Elevating the prospects of green hydrogen (H2) production through solar-powered water splitting devices: A systematic review

As the commercialisation of two contrasting solar-powered water splitting devices with lower TRLs of proton exchange membrane (PEM) electrolyser systems and photoelectrochemical (PEC) systems gains momentum, the path towards a sustainable H2 economy is taking shape. Ongoing pilot projects and demonstration plants are proving the feasibility and potential of these technologies in real-world applications. However, to ensure their success, we must confront the critical challenges of cost reduction and efficiency enhancement, making green H2 economically competitive with traditional production methods. To achieve this, a collaborative effort among academia, industry, and policymakers is paramount. This comprehensive review begins by examining traditional water electrolysis methods, focusing on the production of green H2 through electrochemical splitting. It delves into crucial components and advancements in the PEM systems, addressing challenges related to catalysts, membranes, gas diffusion layers, and bipolar plates. The review also explores solar-driven PEC water splitting, emphasizing the significance of efficient photoelectrodes and reactor design. Additionally, it discusses the integration of photovoltaic cells with electrochemical or PEC systems for higher H2 yield. Commercialisation is underway and this endeavour necessitates a collaborative approach, with active involvement from academia, industry, and policymakers. This collective effort not only propels us towards greener and more sustainable energy solutions but also represents a transformative step in the global journey towards a sustainable and environmentally conscious economy.