Progress and Perspectives for Solar‐Driven Water Electrolysis to Produce Green Hydrogen

Abstract

energy system is among the most promising solutions to solve the above issues. Substituting the current energy carrier with a sustainable fuel is one of the crucial points in the system. Hydrogen as a green and high energy density carrier, primarily derived from water, can satisfy the requirement of sustainable development and facilitate environmental protection and energy conservation. Nowadays, hydrogen is mainly produced from numerous nonrenewable energy such as fossil fuels and biomass for practical applications. [1][2][3] Water electrolysis is a hopeful strategy for efficient and sustainable hydrogen production, but not cost-effective due to the need for large electricity consumption. [4,5] It remains challenging to achieve highly effective hydrogen production with lowcost and renewable energy.Sunlight is an endlessly renewable energy source, which can substitute fossil fuels. In this regard, coupling of sunlight and water electrolysis is desperately needed. The photovoltaic module coupled with water electrolyzers (PV-EC) to achieve the direct conversion of solar energy into hydrogen fuel is a good choice for sustainable energy system. The solar-driven water electrolysis can be achieved through the electrical power generated by a photovoltaic system for driving an external water electrolyzer. [6][7][8] The solar cells do not need to immerse into the electrolyte and not be vulnerable to corrosion in this configuration. However, the high cost of solar photovoltaic devices limits its practical applications. Integrated photoelectrochemical (PEC) devices comprising a photovoltaic device and a water electrolyzer in a single device have aroused much attention. [9][10][11] It allows the direct coupling of light absorbers and catalysts, which could reduce the cost and mechanical limitations. One of the most prominent works is the "artificial leaf", which comprises a triple junction and amorphous silicon photovoltaic interfaced to hydrogen-and oxygen-evolving catalyst for achieving an efficiency of 4.7%. [12] Considering the fluctuating output power and intrinsically intermittent nature of solar energy, a rechargeable energy storage device could be introduced to serve as a reservoir to offer a stable electrical output and accommodate solar energy. The PV-ES-EC system can thus be achieved through the fabrication of an efficient energy storage device to couple the photovoltaic device and water electrolyzer.Notably, the above solar-driven water electrolysis systems require highly conductive and stable separators, highly Solar-driven water electrolysis has been considered to be a promising route to produce green hydrogen, because the conventional water electrolysis system is not completely renewable as it requires power from nonrenewable fossil fuel sources. This review emphasizes the strategies for solar-driven water electrolysis, including the construction of photovoltaic (PV)-water electrolyzer systems, PV-rechargeable energy storage devicewater electrolyzer systems with solar energy as the sole input energy, and photo...

Halide perovskite photovoltaic-electrocatalysis for solar fuel generation

“…Therefore, many studies have been conducted to reduce the OER overpotential using various strategies such as morphology, composition, and interface control. 137 Mainly, transition metals with partially filled d orbitals are used as constituent elements because of fast electron transfer and high catalytic activity for OER. 138 In particular, through the compositional optimization of various non-noble metals, a higher catalytic activity than that of rare earth metals such as Ir and Ru was implemented.…”

Materials Design and System Innovation for Direct and Indirect Seawater Electrolysis

“…The global challenge of energy and environmental issues calls for innovative technologies to decarbonize energy and industry sectors. Currently, nonrenewable fossil fuels such as oil, coal, and natural gas contribute to over 80% of the global energy supply while simultaneously dominating carbon dioxide emissions. , To ensure long-term sustainability, green hydrogen produced from water electrolysis using renewable energy sources (such as solar and wind energy) has been widely considered as the most promising energy carrier in various end-use sectors. − It is highly attractive and feasible due to the significant technological development and cost reduction of renewable electricity. − However, commercial water electrolyzers typically require ultrahigh-purity water as the raw material to maximize service life and save costs, which is an unpractical approach in hot and arid areas where the fresh water supply is insufficient. − In contrast, seawater, accounting for 96.5% of the total water reserves on Earth, is almost an inexhaustible resource, , thus presenting an abundant opportunity for those areas with limited access to freshwater. Moreover, the global coastal arid areas have sufficient potential for photovoltaic and wind power generation. , From a practical perspective, combining seawater electrolysis with coastal solar/offshore wind power is conducive to becoming an attractive choice for renewable energy based hydrogen production technologies (Figure a). − …”

Theoretical Revelation and Experimental Verification Synergistic Electronic Interaction of V-Doped RuNi as an Efficient Bifunctional Electrocatalyst for Overall Water Splitting

“…By comparing the electronic energetic structure and elemental valence changes, it is clear that the addition of H x V 2 O 5 will shift the characteristic peaks to different extent, which thus affect the activity of the catalysts. 30 Moreover, the insertion of metal oxide V during electrocatalysis enhances the electron transport capacity. 31 In addition, RuNiVO electrocatalysts exhibit low OER and HER overpotentials of 224 and 136 mV, respectively, and after long stability test (48 h), the catalyst also showed superior stability with negligible current losses.…”