Abstract
Hydrogen (H2) is regarded as the future supernumerary energy source owing to its lightweight, renewability and greenness. The interest in the photocatalytic hydrogen (H2) evolution over semiconductor photocatalysts has become a robust approach for green fuel production. In the meantime, bismuth tungstate (Bi2WO6) is considered a promising photocatalyst for H2 evolution. This work studied the synthesis and improvement of nanocrystalline Bi2WO6 via a modified sol-gel process followed by anchoring diverse trace portions of silver oxide (Ag2O) support. The prepared nanostructures were utilized for the photocatalytic evolution of H2 under visible-light irradiation in a water/glycerol mixture. The detailed depiction of the gained photocatalysts exposed the synergetic effects of anchoring Ag2O on the light harvesting and semiconducting properties without significant changes to the main surface or crystalline structure. The addition of 3.0 wt% Ag2O on Bi2WO6 has a little reduction on its specific surface area from 145 to 125 m2 g−1. However, visible light absorbance improved due to its bandgap energy reduction from 2.78 to 2.31 eV. The 3% Ag2O/Bi2WO6 utilization at the optimized dose of 2.0 gL‒1 led to efficient H2 generation in the presence of Pt deposits of 3.06 mmol g−1h−1 that sustained a 97% reusability five times. This capable H2 evolution is credited to the extended light harvesting and the robust charge separation by Ag2O anchoring to Bi2WO6.
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