For verification of this paper, please visit on http://www.socialresearchfoundation.com/innovation.php#8

Understanding Water Splitting: The Process and Its Importance

Water splitting is a chemical process that holds significant promise for sustainable hydrogen production, and it begins with a simple yet powerful reaction: the decomposition of water (H₂O) into its elemental components hydrogen (H₂) and oxygen (O₂)[10]. This process is not only pivotal in the context of renewable energy but also plays a critical role in addressing the pressing need for clean fuel alternatives in a world increasingly focused on reducing carbon emissions[11,12].

At its core, water splitting typically involves two electrochemical reactions: the oxidation of water to produce oxygen at the anode and the reduction of protons to generate hydrogen at the cathode. The efficiency of this process hinges on the catalysts used, which can dramatically lower the energy barrier required to initiate the reactions[13–15]. Traditional methods, such as thermal decomposition or electrolysis, can be energy-intensive, leading to questions about their overall sustainability. This is where LDH (Layered Double Hydroxide) catalysts come into play.

LDH catalysts are gaining traction due to their unique structure and composition, which can be tailored for enhanced catalytic activity. Their layered nature allows for the intercalation of various anions and cations, optimizing the catalytic sites available for the reactions. This adaptability not only improves the efficiency of the water splitting process but also promotes the use of abundant, non-toxic materials, making them an appealing choice for researchers focused on sustainable practices[13–15].

The importance of water splitting extends beyond hydrogen production; it represents a fundamental shift towards utilizing renewable resources. Hydrogen, as a clean fuel, can serve as a vital component in various applications, from powering fuel cells in vehicles to providing energy for industrial processes. By harnessing advanced catalysts like LDHs, we can significantly reduce the carbon footprint associated with hydrogen production, paving the way for a greener and more sustainable future.

As the global community endeavours to transition to cleaner energy sources, understanding the intricacies of water splitting and the role of innovative catalysts is essential. The potential for LDH catalysts to revolutionize hydrogen production not only highlights their environmental promise but also underscores their importance in the broader context of sustainable energy solutions.

The Role of LDH Catalysts in Hydrogen Production

Layered double hydroxides (LDHs) are emerging as transformative catalysts in the quest for sustainable hydrogen production through water splitting. Their unique structure, comprised of positively charged layers of metal hydroxides interspersed with anions, allows for remarkable tunability and versatility in catalysis. This inherent flexibility enables LDHs to facilitate both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) with enhanced efficiency compared to traditional catalysts[3,11,16–18].

The layered architecture of LDHs provides a large surface area and abundant active sites, which are critical for accelerating the electrochemical reactions involved in water splitting. When engineered with specific metal combinations such as nickel-cobalt or magnesium-aluminium their catalytic properties can be optimized to maximize hydrogen production rates while minimizing energy input. This is particularly important as the hydrogen economy seeks to reduce reliance on fossil fuels and lower greenhouse gas emissions[19].

Moreover, LDHs exhibit excellent stability and resistance to leaching, which are essential characteristics for long-term applications in real-world conditions. Their ability to maintain activity over extended periods under various operational environments makes them a promising choice for large-scale hydrogen production technologies[1,20].

In addition to their catalytic prowess, LDHs also present a viable pathway for integrating renewable energy sources into hydrogen generation processes. By coupling LDH catalysts with solar or wind energy systems, it is possible to harness clean energy for water splitting, thereby contributing to an eco-friendlier hydrogen production paradigm[21–23].

In conclusion, the role of LDH catalysts in hydrogen production is not only pivotal for enhancing efficiency and stability but also for aligning with global sustainability goals. As research advances, the promise of LDHs could lead to breakthroughs that make hydrogen a cornerstone of a sustainable energy future.

Environmental Impact of Traditional Hydrogen Production Methods

The environmental impact of traditional hydrogen production methods is significant and multifaceted, raising concerns about sustainability and ecological integrity[24]. Historically, the predominant method for hydrogen production has been steam methane reforming (SMR), which involves extracting hydrogen from natural gas[25,26]. This process not only consumes a large volume of fossil fuels but also emits considerable amounts of carbon dioxide (CO2), contributing to greenhouse gas emissions that exacerbate climate change.

In addition to SMR, other traditional methods such as coal gasification and electrolysis powered by non-renewable energy sources further compound the environmental issues at hand. Coal gasification releases not only CO2 but also other harmful pollutants, including sulfur dioxide (SO₂) and nitrogen oxides (NO_x), which can lead to acid rain and respiratory problems in humans. Similarly, electrolysis of H₂O inherently cleaner becomes problematic when the electricity required is derived from fossil fuels, thereby negating its potential benefits.

Moreover, the production of hydrogen through these conventional methods often results in significant water usage, straining local water resources, especially in arid regions. This creates an unsustainable cycle where water scarcity becomes a pressing issue as demand for hydrogen continues to rise.

As industries and governments increasingly focus on transitioning to greener alternatives, the environmental footprints of these traditional hydrogen production methods are under scrutiny. The urgency for innovative solutions that minimize ecological impact is palpable, positioning LDH (layered double hydroxide) catalysts as a beacon of promise[4,14,27–29]. By harnessing the potential of these catalysts, we can not only reduce the carbon footprint associated with hydrogen production but also move towards a more sustainable and environmentally friendly approach to meeting global energy needs.

Advantages of LDH Catalysts Over Conventional Catalysts

In the quest for sustainable hydrogen production, Layered Double Hydroxides (LDH) catalysts are emerging as a game-changer, offering several advantages over traditional catalytic materials[4,14,27–29]. Conventional catalysts, often based on noble metals such as platinum or palladium, come with significant drawbacks: they are expensive, rare, and can be less effective in certain reaction environments. In contrast, LDH catalysts are composed of abundant, non-toxic elements, making them a more sustainable and cost-effective solution for water splitting[4,14,27–29].

One of the standout benefits of LDH catalysts is their unique structural properties. With a layered architecture, these catalysts provide a high surface area, facilitating greater interaction with reactants and enhancing catalytic activity. This characteristic not only increases the efficiency of hydrogen production but also allows for the potential fine-tuning of the catalyst's composition, enabling researchers to optimize performance for specific reactions[30].

Moreover, LDH catalysts demonstrate excellent stability under a variety of operating conditions. Unlike conventional catalysts that may suffer from leaching or deactivation over time, LDHs maintain their structural integrity and functionality, resulting in longer operational lifetimes and reduced replacement costs. This stability is crucial for large-scale hydrogen production, where continuous operation is essential for economic viability[7,31].

Another significant advantage lies in the ease of synthesis and modification of LDH catalysts. These materials can be produced using straightforward, low-cost methods, and their properties can be tailored through the incorporation of different metal ions or anions. This flexibility not only makes it easier to scale up production but also allows for the development of catalysts that can be specifically designed to meet the demands of various applications in green energy technologies.

In summary, the advantages of LDH catalysts over conventional catalysts ranging from cost-effectiveness and stability to tunability and scalability, position them as promising candidates for revolutionizing sustainable hydrogen production through water splitting. As research continues to explore their full potential, LDH catalysts may play a pivotal role in the transition to a more sustainable and hydrogen-powered future[32].

Mechanisms of LDH Catalysts in Water Splitting

The mechanisms by which Layered Double Hydroxide (LDH) catalysts facilitate water splitting are both intricate and fascinating, making them a focal point of research in the pursuit of sustainable hydrogen production. At the core of this process is the unique layered structure of LDH materials, which allows for enhanced ionic conductivity and more effective charge separation when exposed to light or electrical energy.

LDH catalysts, composed of metal cations and anionic species, operate through a series of electrochemical reactions. When water is split, two primary reactions occur: the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER). The OER involves the oxidation of water molecules to produce oxygen gas, while the HER focuses on reducing protons to generate hydrogen gas. LDH materials serve as active sites for these reactions, promoting the necessary electron transfer processes[7,33].

One of the key advantages of LDH catalysts is their tunability. Researchers can manipulate the metal composition and anionic interlayers to optimize their catalytic activity and stability. For instance, incorporating transition metals such as nickel, cobalt, or iron can enhance the overall efficiency of the catalyst, allowing for lower energy inputs and faster reaction rates. Additionally, the presence of intercalated anions can influence the electronic properties of the catalyst, further improving its performance in water splitting[34].

Moreover, LDH catalysts exhibit remarkable stability under operational conditions, which is essential for long-term applications in renewable energy systems. The layered structure not only provides robustness but also allows for the sustained exposure to corrosive environments that typically challenge other catalyst types.

Recent studies have also highlighted the role of LDH catalysts in facilitating synergistic effects when combined with other materials, such as carbon-based supports or conductive polymers. These hybrid systems leverage the strengths of each component, resulting in enhanced performance and increased hydrogen production rates.

As we delve deeper into the mechanisms of LDH catalysts in water splitting, it becomes evident that their unique properties and versatile nature present a promising avenue for advancing sustainable hydrogen production. By unlocking the full potential of these materials, researchers are paving the way for cleaner, more efficient energy solutions that could play a critical role in addressing global energy demands and mitigating environmental impacts[24,32].

Recent Advances in LDH Catalyst Research

In recent years, the field of Layered Double Hydroxides (LDHs) has witnessed a remarkable surge in research and development, driven by the pressing need for sustainable energy solutions and the quest for efficient hydrogen production through water splitting. Researchers have been tirelessly exploring innovative approaches to enhance the catalytic performance of LDH materials, focusing on their unique structural properties and tunable composition.

One of the most significant advancements has been the incorporation of various metal ions into the LDH framework, which allows for the fine-tuning of electronic and catalytic properties. For instance, the introduction of transition metals such as nickel, cobalt, or iron has been shown to dramatically improve the hydrogen evolution reaction (HER) efficiency. This customization not only enhances activity but also optimizes stability under operational conditions, addressing one of the critical challenges in the practical application of LDH catalysts[35,36].

Another promising development is the exploration of hybrid LDH systems, where LDHs are combined with other materials, such as carbon-based nanomaterials or conductive polymers. These hybrids leverage the high surface area and dispersion capabilities of LDHs while benefiting from the superior electrical conductivity of the complementary materials. As a result, researchers have observed significant improvements in charge transfer kinetics, leading to enhanced overall reaction rates during water splitting.

Moreover, advances in synthesis methods, such as the use of electrochemical or sol-gel processes, have enabled the production of LDH catalysts with controlled morphology and particle size. This precision in fabrication not only increases the active surface area but also allows for the development of more robust and durable catalysts that can withstand the harsh conditions typically encountered in electrochemical reactions.

Field trials and pilot projects are also emerging, highlighting the scalability and real-world applicability of these advanced LDH catalysts. Researchers are now focusing on integrating these catalysts into solar-driven systems and other renewable energy setups, thereby paving the way for sustainable hydrogen production on a larger scale[7,33,37].

As the momentum in LDH catalyst research continues to build, the potential for these materials to contribute to a greener future becomes increasingly evident. With ongoing innovations and a commitment to sustainability, LDH catalysts are well-positioned to play a pivotal role in addressing global energy challenges and fostering the transition to clean hydrogen fuel[38].

Challenges in Harnessing LDH Catalysts for Industrial Use

While layered double hydroxide (LDH) catalysts hold immense promise for sustainable hydrogen production through water splitting, their transition from laboratory research to industrial application is fraught with challenges. One of the primary hurdles is related to the stability and durability of these catalysts under real-world operating conditions[39,40]. In controlled laboratory settings, LDH catalysts often exhibit impressive activity and selectivity. However, when subjected to the harsh environments typical of industrial processes such as high temperatures, varying pH levels, and the presence of impurities their performance can significantly degrade[41–43].

Moreover, the scalability of LDH synthesis poses another challenge. Most promising LDH catalysts are developed in small batches, using specific precursor materials and intricate synthesis methods that may not be easily scalable. To harness the full potential of these catalysts, industries will need to develop cost-effective and efficient production processes that can maintain their beneficial properties while catering to the larger volumes required for commercial hydrogen production.

Additionally, there exists a need for comprehensive understanding in terms of the operational mechanisms of LDH catalysts. While research has made strides in elucidating their fundamental behaviors, the complexity of real-world reactions and the interaction of LDHs with other materials can lead to unpredictable outcomes. This unpredictability can hinder the optimization of process conditions essential for maximizing hydrogen output.

Finally, regulatory and economic factors also play a critical role in the widespread adoption of LDH catalysts. The transition to alternative energy sources, including hydrogen, requires significant investment and infrastructure changes, which can be daunting for many organizations. Securing funding, navigating regulatory frameworks, and competing with established technologies present formidable obstacles.

Addressing these multifaceted challenges will be crucial for unlocking the full potential of LDH catalysts. To make them a viable option in the quest for sustainable hydrogen production, concerted efforts in research, engineering, and policy-making will be necessary, paving the way for innovative solutions that can ultimately lead to a greener future.

Life Cycle Assessment of LDH Catalysts

Life Cycle Assessment (LCA) is a crucial tool in evaluating the environmental impact of Layered Double Hydroxide (LDH) catalysts, particularly in the context of sustainable hydrogen production through water splitting. By systematically analysing the entire life cycle of these catalysts from raw material extraction and production to usage, maintenance, and eventual disposal we can gain a comprehensive understanding of their environmental footprint.

The LCA process begins with a thorough inventory of inputs and outputs associated with the production of LDH catalysts. This includes the sourcing of precursor materials, energy consumption during synthesis, and the emissions generated throughout these phases. By quantifying these factors, researchers can identify hotspots where improvements can be made, such as optimizing energy use or selecting more sustainable raw materials.

Next, the assessment focuses on the operational phase of LDH catalysts. Evaluating their efficiency in catalyzing water splitting reactions and the resulting hydrogen production is essential. This phase not only considers the performance of the catalysts but also the lifecycle impacts of the hydrogen generated, particularly in terms of its potential for reducing greenhouse gas emissions when utilized in fuel cells or other applications.

Finally, the LCA addresses the end-of-life scenarios for LDH catalysts. It considers options such as recycling, repurposing, or safe disposal, which are vital for minimizing their impact on the environment. By exploring these pathways, we can determine the most sustainable practices for managing LDH catalysts post-use.

Through a thoughtful application of LCA, researchers and industry stakeholders can make informed decisions that enhance the sustainability profile of LDH catalysts. This analysis not only supports the development of environmentally friendly hydrogen production methods but also underscores the promise of LDH catalysts in contributing to a greener future.

Future Prospects for LDH Catalysts in Sustainable Energy

As the demand for sustainable energy solutions continues to escalate, the future prospects for Layered Double Hydroxide (LDH) catalysts in hydrogen production through water splitting look increasingly promising. With their unique structural properties and tunable composition, LDH catalysts offer a compelling alternative to traditional catalysts, paving the way for more efficient and environmentally friendly hydrogen generation processes[44–46].

In recent years, researchers have made significant strides in enhancing the performance of LDH catalysts by optimizing their composition and morphology. This optimization not only improves their catalytic activity but also increases their stability under operational conditions, making them more viable for long-term applications. As advancements in material science and nanotechnology continue, we can expect even greater improvements in LDH catalyst efficiency, which could dramatically lower the energy costs associated with water splitting.

Moreover, the integration of LDH catalysts into renewable energy systems presents an exciting avenue for future exploration. For instance, coupling these catalysts with solar energy harnessing technologies could lead to the development of decentralized hydrogen production units that operate in tandem with solar panels. This synergy would enable communities to produce hydrogen locally, reducing reliance on fossil fuels and minimizing carbon emissions[47–50].

Additionally, the potential for LDH catalysts in other sustainable applications such as carbon capture and storage opens up new avenues for research and development. By leveraging their unique properties, LDH materials could play a crucial role in reducing greenhouse gas emissions while simultaneously facilitating the transition towards a hydrogen economy.

In summary, the future of LDH catalysts in sustainable energy is filled with possibilities. As we continue to innovate and refine these materials, the prospect of scalable, efficient, and environmentally friendly hydrogen production becomes not just a hope, but a tangible goal. With continued investment and research, LDH catalysts could be at the forefront of the green energy revolution, helping to mitigate climate change and foster a sustainable future.

Policy Implications for Supporting LDH Catalyst Research

As the global community pivots towards sustainable energy solutions, the role of policy in fostering research and development of layered double hydroxide (LDH) catalysts cannot be overstated. Governments and regulatory bodies must recognize the pivotal role that these catalysts can play in advancing hydrogen production through water splitting process that holds tremendous promise for a cleaner energy future[51].

To support LDH catalyst research effectively, policymakers should consider establishing dedicated funding programs aimed at academic institutions and research organizations focused on nanomaterials and catalytic processes. By providing grants or subsidies, governments can stimulate innovation, encouraging scientists to explore new formulations and techniques that enhance the efficiency and stability of LDH catalysts.

Furthermore, creating collaborative frameworks between public and private sectors can drive the commercialization of LDH technologies. By incentivizing partnerships, policymakers can leverage the expertise and resources of the private sector while ensuring that research aligns with environmental goals. Initiatives such as innovation hubs or technology incubators specifically for sustainable energy solutions can facilitate this synergy, promoting knowledge exchange and accelerating the development of practical applications.

Moreover, regulatory frameworks should prioritize sustainability metrics in assessing new technologies. By integrating life cycle assessments and environmental impact evaluations into the research funding criteria, policymakers can ensure that only the most effective and eco-friendly solutions receive support. This approach not only guides researchers toward impactful innovations but also assures the public and stakeholders that investments are being made in technologies that will benefit the environment.

Additionally, outreach programs aimed at raising awareness about the potential of LDH catalysts can further enhance public and private investment in this area. By showcasing successful case studies and the positive implications of hydrogen production for energy security and climate change mitigation, policymakers can inspire a broader commitment to research and development in sustainable technologies.

In conclusion, the promise of LDH catalysts in sustainable hydrogen production hinges not just on scientific discovery but also on the robust support of policies that encourage research, collaboration, and environmental accountability. Through thoughtful policy implications, we can pave the way for a cleaner energy future, harnessing the full potential of these innovative catalysts.

Conclusion: The Promise of LDH Catalysts for a Greener Future

In conclusion, layered double hydroxide (LDH) catalysts represent a groundbreaking advancement in the quest for sustainable hydrogen production through water splitting. Their unique structural properties and tunable compositions not only enhance catalytic efficiency but also provide a pathway to greener chemical processes. By facilitating the electrochemical reactions necessary for hydrogen generation, LDH catalysts offer an eco-friendly alternative to traditional methods that often rely on fossil fuels and generate harmful emissions.

As we face the pressing challenges of climate change and dwindling natural resources, the promise of LDH catalysts cannot be overstated. They embody the potential to significantly reduce our carbon footprint while meeting the growing energy demands of our modern world. With ongoing research and innovation in this field, we can expect to see even more optimized formulations and applications that further enhance their performance and sustainability.

Investing in LDH catalyst technology not only aligns with environmental goals but also positions industries at the forefront of the green energy transition. As we harness their capabilities, we move closer to a future where clean, renewable hydrogen can be produced efficiently and economically, paving the way for a cleaner planet. Embracing LDH catalysts is not merely a scientific endeavor; it's a commitment to building a sustainable future for generations to come. The time to act is now, and the potential of these catalysts stands as a beacon of hope in our pursuit of environmental stewardship.

Further Reading and Resources on LDH Catalysts and Hydrogen Production

For those looking to deepen their understanding of Layered Double Hydroxides (LDH) catalysts and their pivotal role in sustainable hydrogen production through water splitting, a wealth of resources is available. These materials provide valuable insights into both the theoretical frameworks and practical applications of LDH catalysts in energy conversion technologies.

To start, consider delving into academic journals such as Energy & Environmental Science and Journal of Catalysis, where we find peer-reviewed articles detailing recent advancements, experimental methodologies, and case studies focusing on LDH catalysts. These publications often highlight innovative techniques and provide comparative analyses with other catalytic materials, allowing readers to grasp the current landscape of hydrogen production research.

Additionally, there are numerous online platforms that host webinars and workshops led by experts in the field. Websites like ResearchGate and LinkedIn Learning offer access to discussions and presentations that cover emerging trends, best practices, and collaborative opportunities in the realm of hydrogen energy.

Books such as *Hydrogen Production: Fundamentals and Case Studies* provide comprehensive overviews of various hydrogen production methods, including the role of LDH catalysts. These texts often serve as excellent foundational resources for both students and professionals seeking to expand their knowledge.

For those interested in practical applications, consider exploring industry reports from organizations such as the International Energy Agency (IEA) or the U.S. Department of Energy (DOE), which often publish analyses on the environmental impact and economic viability of hydrogen production technologies.

Finally, engaging with online forums and communities dedicated to sustainable energy can also prove beneficial. Platforms like Reddit or specialized Facebook groups facilitate discussions where enthusiasts and experts alike share resources, ask questions, and exchange ideas related to LDH catalysts and hydrogen production.

By tapping into these diverse resources, you can enrich your understanding of LDH catalysts and their promising potential in the transition towards a more sustainable energy future.

Call to Action: Encouraging Innovation in Sustainable Technologies

As we stand at the crossroads of environmental challenge and technological opportunity, the call to action for innovation in sustainable technologies has never been more urgent. The landscape of energy production is evolving, and with it comes the imperative to harness new methods that can mitigate the effects of climate change and promote a healthier planet. LDH (Layered Double Hydroxide) catalysts present a promising avenue in this pursuit, particularly in the realm of sustainable hydrogen production through water splitting.

To truly realize the potential of LDH catalysts, we must encourage a collaborative approach among researchers, engineers, and industry leaders. This can be achieved by fostering interdisciplinary partnerships that bring together expertise in materials science, chemistry, and environmental policy. Innovation thrives in environments where diverse minds converge, and your ideas could play a pivotal role in this transformation.

Moreover, investing in education and awareness around the benefits of LDH catalysts and water splitting technology is crucial. By sharing knowledge and encouraging dialogue about sustainable practices, we can inspire the next generation of scientists and entrepreneurs who will continue to push the boundaries of what is possible.

Finally, consider this your invitation to be part of the movement. Whether you are a seasoned professional in the field or a passionate newcomer, your contribution matters. Engage with communities dedicated to sustainable technologies, participate in forums and discussions, and advocate for policies that support research and development in this vital area. Together, we can innovate, inspire, and implement the changes needed to create a more sustainable future powered by clean hydrogen. The time for action is now let's seize this opportunity to make a meaningful impact on our world.

1. S. Venkata Mohan, A. Pandey, Sustainable Hydrogen Production, Biomass, Biofuels, Biochem. Biohydrogen, Second Ed. 305 (2019) 1–23. https://doi.org/10.1016/B978-0-444-64203-5.00001-0.
2. J. Ran, J. Yu, M. Jaroniec, Ni(OH)2 modified CdS nanorods for highly efficient visible-light-driven photocatalytic H2 generation, Green Chem. 13 (2011) 2708–2713. https://doi.org/10.1039/c1gc15465f.
3. S. Anantharaj, S. Kundu, S. Noda, Progress in nickel chalcogenide electrocatalyzed hydrogen evolution reaction, J. Mater. Chem. A. 8 (2020) 4174–4192. https://doi.org/10.1039/c9ta14037a.
4. Y. Wang, D. Yan, S. El Hankari, Y. Zou, S. Wang, Recent Progress on Layered Double Hydroxides and Their Derivatives for Electrocatalytic Water Splitting, Adv. Sci. 5 (2018). https://doi.org/10.1002/advs.201800064.
5. P.H. Cyril, G. Saravanan, Development of advanced materials for cleaner energy generation through fuel cells, New J. Chem. 44 (2020) 19977–19995. https://doi.org/10.1039/d0nj03746j.
6. Z.W. She, J. Kibsgaard, C.F. Dickens, I. Chorkendorff, J.K. Nørskov, T.F. Jaramillo, Combining theory and experiment in electrocatalysis: Insights into materials design, Science (80-. ). 355 (2017). https://doi.org/10.1126/science.aad4998.
7. S.M.I. Shamsah, Earth-Abundant Electrocatalysts for Water Splitting : Current and Future Directions, Catalysts. 11 (2021) 429. https://doi.org/10.3390/catal11040429.
8. . Chu, A. Majumdar, Opportunities and challenges for a sustainable energy future, Nature. 488 (2012) 294–303. https://doi.org/10.1038/nature11475.
9. H. Xu, J. Wei, K. Zhang, M. Zhang, C. Liu, J. Guo, Y. Du, Constructing bundle-like Co-Mn oxides and Co-Mn selenides for efficient overall water splitting, J. Mater. Chem. A. 6 (2018) 22697–22704. https://doi.org/10.1039/c8ta07449f.
10. J. Baltrusaitis, D.M. Cwiertny, V.H. Grassian, Adsorption of sulfur dioxide on hematite and goethite particle surfaces, Phys. Chem. Chem. Phys. 9 (2007) 5542–5554. https://doi.org/10.1039/b709167b.
11. A. Indra, A. Acharjya, P.W. Menezes, C. Merschjann, D. Hollmann, M. Schwarze, M. Aktas, A. Friedrich, S. Lochbrunner, A. Thomas, M. Driess, Boosting Visible‐Light‐Driven Photocatalytic Hydrogen Evolution with an Integrated Nickel Phosphide–Carbon Nitride System, Angew. Chemie. 129 (2017) 1675–1679. https://doi.org/10.1002/ange.201611605.
12. K.N. Chaudhari, M.Y. Song, J.S. Yu, Transforming hair into heteroatom-doped carbon with high surface area, Small. 10 (2014) 2625–2636. https://doi.org/10.1002/smll.201303831.
13. Y. Wu, H. Wang, S. Ji, X. Tian, G. Li, X. Wang, R. Wang, Ultrastable NiFeOOH/NiFe/Ni electrocatalysts prepared by in-situ electro-oxidation for oxygen evolution reaction at large current density, Appl. Surf. Sci. 564 (2021) 150440. https://doi.org/10.1016/j.apsusc.2021.150440.
14. P. Ding, H. Song, J. Chang, S. Lu, N-doped carbon dots coupled NiFe-LDH hybrids for robust electrocatalytic alkaline water and seawater oxidation, Nano Res. 15 (2022) 7063–7070. https://doi.org/10.1007/s12274-022-4377-4.
15. J.J. Zhang, W.W. Bao, M.Y. Li, C.M. Yang, N.N. Zhang, Ultrafast formation of an FeOOH electrocatalyst on Ni for efficient alkaline water and urea oxidation, Chem. Commun. 56 (2020) 14713–14716. https://doi.org/10.1039/d0cc05592a.
16. B. Jones, K.R. Davies, M.G. Allan, S. Anantharaj, I. Mabbett, T. Watson, J.R. Durrant, M.F. Kuehnel, S. Pitchaimuthu, Photoelectrochemical concurrent hydrogen generation and heavy metal recovery from polluted acidic mine water, Sustain. Energy Fuels. 5 (2021) 3084–3091. https://doi.org/10.1039/d1se00232e.
17. X. Wang, R. Liu, Y. Zhang, L. Zeng, A. Liu, Hierarchical Ni 3 S 2 -NiOOH hetero-nanocomposite grown on nickel foam as a noble-metal-free electrocatalyst for hydrogen evolution reaction in alkaline electrolyte, Appl. Surf. Sci. 456 (2018) 164–173. https://doi.org/10.1016/j.apsusc.2018.06.107.
18. A. Indra, P.W. Menezes, K. Kailasam, D. Hollmann, M. Schröder, A. Thomas, A. Brückner, M. Driess, Nickel as a co-catalyst for photocatalytic hydrogen evolution on graphitic-carbon nitride (sg-CN): What is the nature of the active species?, Chem. Commun. 52 (2016) 104–107. https://doi.org/10.1039/c5cc07936e.
19. A. Indra, U. Paik, T. Song, Boosting Electrochemical Water Oxidation with Metal Hydroxide Carbonate Templated Prussian Blue Analogues, Angew. Chemie - Int. Ed. 57 (2018) 1241–1245. https://doi.org/10.1002/anie.201710809.
20. J. Wang, T. Liao, Z. Wei, J. Sun, J. Guo, Z. Sun, Heteroatom-Doping of Non-Noble Metal-Based Catalysts for Electrocatalytic Hydrogen Evolution: An Electronic Structure Tuning Strategy, Small Methods. 5 (2021) 1–27. https://doi.org/10.1002/smtd.202000988.
21. Y. Ma, Y. Ma, Q. Wang, S. Schweidler, M. Botros, T. Fu, H. Hahn, T. Brezesinski, B. Breitung, High-entropy energy materials: Challenges and new opportunities, Energy Environ. Sci. 14 (2021) 2883–2905. https://doi.org/10.1039/d1ee00505g.
22. S. Dou, L. Tao, J. Huo, S. Wang, L. Dai, Etched and doped Co9S8/graphene hybrid for oxygen electrocatalysis, Energy Environ. Sci. 9 (2016) 1320–1326. https://doi.org/10.1039/c6ee00054a.
23. H. Su, X. Zhao, W. Cheng, H. Zhang, Y. Li, W. Zhou, M. Liu, Q. Liu, Hetero-N-Coordinated Co Single Sites with High Turnover Frequency for Efficient Electrocatalytic Oxygen Evolution in an Acidic Medium, ACS Energy Lett. 4 (2019) 1816–1822. https://doi.org/10.1021/acsenergylett.9b01129.
24. A. Maiti, S.K. Srivastava, Sulphur edge and vacancy assisted nitrogen-phosphorus co-doped exfoliated tungsten disulfide: A superior electrocatalyst for hydrogen evolution reaction, J. Mater. Chem. A. 6 (2018) 19712–19726. https://doi.org/10.1039/c8ta06918b.
25. New York State Energy Research and Development Authority, HYDROGEN FACT SHEET Hydrogen Production – Steam Methane Reforming (SMR), (2004) 4. www.nyserda.org.
26. A.P. Simpson, A.E. Lutz, Exergy analysis of hydrogen production via steam methane reforming, Int. J. Hydrogen Energy. 32 (2007) 4811–4820. https://doi.org/10.1016/j.ijhydene.2007.08.025.
27. J. Fan, X. Qin, W. Jiang, X. Lu, X. Song, W. Guo, S. Zhu, Interface-Coupling of NiFe-LDH on Exfoliated Black Phosphorus for the High-Performance Electrocatalytic Oxygen Evolution Reaction, Front. Chem. 10 (2022) 1–10. https://doi.org/10.3389/fchem.2022.951639.
28. X. Xu, X. Yu, K. Guo, L. Dong, X. Miao, Alkaline Media Regulated NiFe-LDH-Based Nickel–Iron Phosphides toward Robust Overall Water Splitting, Catalysts. 13 (2023). https://doi.org/10.3390/catal13010198.
29. H.S. Chavan, C.H. Lee, A.I. Inamdar, J. Han, S. Park, S. Cho, N.K. Shreshta, S.U. Lee, B. Hou, H. Im, H. Kim, Designing and Tuning the Electronic Structure of Nickel-Vanadium Layered Double Hydroxides for Highly Efficient Oxygen Evolution Electrocatalysis, ACS Catal. 12 (2022) 3821–3831. https://doi.org/10.1021/acscatal.1c05813.
30. [M. Fu, X. Ma, K. Zhao, X. Li, D. Su, High-entropy materials for energy-related applications, IScience. 24 (2021) 102177. https://doi.org/10.1016/j.isci.2021.102177.
31. [31]         G. Liu, P. Li, G. Zhao, X. Wang, J. Kong, H. Liu, H. Zhang, K. Chang, X. Meng, T. Kako, J. Ye, Promoting Active Species Generation by Plasmon-Induced Hot-Electron Excitation for Efficient Electrocatalytic Oxygen Evolution, J. Am. Chem. Soc. 138 (2016) 9128–9136. https://doi.org/10.1021/jacs.6b05190.
32. J.P. Paraknowitsch, A. Thomas, Doping carbons beyond nitrogen: An overview of advanced heteroatom doped carbons with boron, sulphur and phosphorus for energy applications, Energy Environ. Sci. 6 (2013) 2839–2855. https://doi.org/10.1039/c3ee41444b.
33. J. Luo, J.H. Im, M.T. Mayer, M. Schreier, M.K. Nazeeruddin, N.G. Park, S.D. Tilley, H.J. Fan, M. Grätzel, Water photolysis at 12.3% efficiency via perovskite photovoltaics and Earth-abundant catalysts, Science (80-. ). 345 (2014) 1593–1596. https://doi.org/10.1126/science.1258307.
34. Y. Lee, J. Suntivich, K.J. May, E.E. Perry, Y. Shao-Horn, Synthesis and activities of rutile IrO 2 and RuO 2 nanoparticles for oxygen evolution in acid and alkaline solutions, J. Phys. Chem. Lett. 3 (2012) 399–404. https://doi.org/10.1021/jz2016507.
35. Y. Huang, L.W. Jiang, B.Y. Shi, K.M. Ryan, J.J. Wang, Highly Efficient Oxygen Evolution Reaction Enabled by Phosphorus Doping of the Fe Electronic Structure in Iron–Nickel Selenide Nanosheets, Adv. Sci. 8 (2021) 1–7. https://doi.org/10.1002/advs.202101775.
36. M. Kumar, R.P. Singh, Unlocking Oxygen Evolution : The Impact of Hetero Atom Doping on NiFe-Based Pre-Catalysts and Their Transformation into Ultrathin Layered Double Hydroxides, 13 (2024) 1446–1451.
37. A. Indra, P. Maity, S. Bhaduri, G.K. Lahiri, Chemoselective Hydrogenation and Transfer Hydrogenation of Olefins and Carbonyls with the Cluster-Derived Ruthenium Nanocatalyst in Water, ChemCatChem. 5 (2013) 322–330. https://doi.org/10.1002/cctc.201200448.
38. Y. Tian, S. Wang, E. Velasco, Y. Yang, L. Cao, L. Zhang, X. Li, Y. Lin, Q. Zhang, L. Chen, A Co-Doped Nanorod-like RuO2 Electrocatalyst with Abundant Oxygen Vacancies for Acidic Water Oxidation, IScience. 23 (2020) 100756. https://doi.org/10.1016/j.isci.2019.100756.
39. J. Hu, S. Li, J. Chu, S. Niu, J. Wang, Y. Du, Z. Li, X. Han, P. Xu, Understanding the Phase-Induced Electrocatalytic Oxygen Evolution Reaction Activity on FeOOH Nanostructures, ACS Catal. (2019) 10705–10711. https://doi.org/10.1021/acscatal.9b03876.
40. J. Li, J. Song, B.Y. Huang, G. Liang, W. Liang, G. Huang, Y. Qi Jin, H. Zhang, F. Xie, J. Chen, N. Wang, Y. Jin, X.B. Li, H. Meng, Enhancing the oxygen evolution reaction performance of NiFeOOH electrocatalyst for Zn-air battery by N-doping, J. Catal. 389 (2020) 375–381. https://doi.org/10.1016/j.jcat.2020.06.022.
41. Q. Jia, F. Su, Z. Li, X. Huang, L. He, M. Wang, Z. Zhang, S. Fang, N. Zhou, Tunable Hollow Bimetallic MnFe Prussian Blue Analogue as the Targeted pH-Responsive Delivery System for Anticancer Drugs, ACS Appl. Bio Mater. 2 (2019) 2143–2154. https://doi.org/10.1021/acsabm.9b00129.
42. L.F. Li, Y.F. Li, Z.P. Liu, Oxygen Evolution Activity on NiOOH Catalysts: Four-Coordinated Ni Cation as the Active Site and the Hydroperoxide Mechanism, ACS Catal. 10 (2020) 2581–2590. https://doi.org/10.1021/acscatal.9b04975.
43. S. Dutta, A. Indra, H.S. Han, T. Song, An Intriguing Pea-Like Nanostructure of Cobalt Phosphide on Molybdenum Carbide Incorporated Nitrogen-Doped Carbon Nanosheets for Efficient Electrochemical Water Splitting, ChemSusChem. 11 (2018) 3956–3964. https://doi.org/10.1002/cssc.201801810.
44. W. Xia, J. Zhu, W. Guo, L. An, D. Xia, R. Zou, Well-defined carbon polyhedrons prepared from nano metal-organic frameworks for oxygen reduction, J. Mater. Chem. A. 2 (2014) 11606–11613. https://doi.org/10.1039/c4ta01656d.
45. L. Cai, J. Zhao, H. Li, J. Park, I.S. Cho, H.S. Han, X. Zheng, One-Step Hydrothermal Deposition of Ni:FeOOH onto Photoanodes for Enhanced Water Oxidation, ACS Energy Lett. 1 (2016) 624–632. https://doi.org/10.1021/acsenergylett.6b00303.
46. X. Shu, M. Yang, D. Tan, K.S. Hui, K.N. Hui, J. Zhang, Recent advances in the field of carbon-based cathode electrocatalysts for Zn-air batteries, Mater. Adv. 2 (2021) 96–114. https://doi.org/10.1039/d0ma00745e.
47. S. Niu, W.J. Jiang, Z. Wei, T. Tang, J. Ma, J.S. Hu, L.J. Wan, Se-Doping Activates FeOOH for Cost-Effective and Efficient Electrochemical Water Oxidation, J. Am. Chem. Soc. 141 (2019) 7005–7013. https://doi.org/10.1021/jacs.9b01214.
48. X. Chen, Q. Wang, Y. Cheng, H. Xing, J. Li, X. Zhu, L. Ma, Y. Li, D. Liu, S-Doping Triggers Redox Reactivities of Both Iron and Lattice Oxygen in FeOOH for Low-Cost and High-Performance Water Oxidation, Adv. Funct. Mater. 32 (2022). https://doi.org/10.1002/adfm.202112674.
49. J. Yu, Q. Li, Y. Li, C.Y. Xu, L. Zhen, V.P. Dravid, J. Wu, Ternary Metal Phosphide with Triple-Layered Structure as a Low-Cost and Efficient Electrocatalyst for Bifunctional Water Splitting, Adv. Funct. Mater. 26 (2016) 7644–7651. https://doi.org/10.1002/adfm.201603727.
50. S. Anantharaj, Ru-tweaking of non-precious materials: The tale of a strategy that ensures both cost and energy efficiency in electrocatalytic water splitting, J. Mater. Chem. A. 9 (2021) 6710–6731. https://doi.org/10.1039/d0ta12424a.
51. A. Lal, F. You, Economic Benefits from Planned Renewable Installations in the US using Hydrogen and Modular Ammonia Production Units, Comput. Aided Chem. Eng. 52 (2023) 2839–2846. https://doi.org/10.1016/B978-0-443-15274-0.50452-2.