Mechanistic Insights into Photocatalytic WO3 for Hydrogen Generation

Growing environmental concerns and the limitations of fossil fuel resources have recently led to increased focus on clean and renewable energy sources. Hydrogen (H2) has gained importance as an alternative clean fuel with its potential to become the primary chemical energy carrier. Photocatalytic hydrogen generation offers a capable solution to the energy crisis and has gained significant attention as a renewable energy solution, offering independence from fossil fuels and zero carbon dioxide emissions. Tungsten oxide (WO3) offers to be a promising photocatalyst for Hydrogen Evolution Reaction (HER) with its ability to tune the band gap, robust absorption in the visible spectrum range, steadiness in harsh reaction conditions, low cost, and reduced toxicity. Various synthetic methods can be employed to fabricate photocatalysts with diverse morphologies, sizes, and structures, all of which significantly influence their catalytic performance to varying extents. This review goals to explicitly highlight and discourse the main properties of WO3 and its modifications for photocatalytic HER via different synthesis methods. Modification in WO3 to its corresponding composites, heterojunctions are explicitly explained in this review.