Photocatalytic whole H2O splitting using Bi0-decorated g-C3N4/SrTiO3 sheet-like catalyst under simulated sunlight

Abstract

The production of hydrogen via photocatalytic water splitting presents considerable opportunities for promoting the advancement of renewable energy. We synthesized sheet-liked nanoparticles of g-C₃N₄/SrTiO₃ composite exhibited a type II heterojunction for hydrogen production from photocatalytic water splitting reaction. To address the limitation of light absorptivity and enhance the photocatalytic hydrogen evolution rate, noble metals are widely used as cocatalysts even though they are overpriced. Replacing noble metals with earth-abundant metals is indispensable for solar hydrogen's affordable price and up-scale ability. We introduced metallic bismuth decorated in g-C₃N₄/SrTiO₃ type II heterojunction by in-situ photoreduction. Under light irradiation, Bi³⁺ was reduced to Bi⁰ by photogenerated electrons, allowing it to act as a non-noble metal cocatalyst for hydrogen production from photocatalytic whole water splitting under simulated sunlight for the first time. At the optimal amount of bismuth-added (1 mol%), g-C₃N₄/SrTiO₃-based photocatalyst had the most remarkable hydrogen evolution rate, approximately 1800 μmol/g after 5 h under simulated sunlight AM 1.5G, 46-fold higher than the composite catalyst without Bi-decorated. The photocatalytic hydrogen production from deionized water was also conducted, which achieved a noteworthy value of 138.7 μmol/g after 5 h under simulated sunlight. The stability test indicated that 1 %Bi/g-C₃N₄/SrTiO₃ could maintain its photocatalytic ability well after four cycles.