Bismuth sulfide-impregnated cobalt oxide nanocrystals: An enhanced photocatalyst for improved hydrogen production beneath visible light

Abstract

Hydrogen (H2) is the lightest and greenest fuel compared to conventional energy resources. The production of H2 could be achieved via several techniques as renewable energy sources. Due to its simplicity, the visible-light H2 evolution over nanocomposite photocatalysts is an emerging method. Following this, the surfactant-aided sol–gel way has grown Cobalt oxide (Co3O4) nanoparticles. 3.0–12.0 wt% of bismuth sulfide (Bi2S3) nanocrystals were added to Co3O4 by impregnating technique to enhance the visible-light photoactivity. The produced nanostructures were utilized to generate H2 by photocatalytic reaction in a water/glycerol medium with platinum traces cocatalyst. The impregnation of Bi2S3 at 9.0 wt% has endorsed the photogenerated H2 by ∼ 8.7 folds (∼1547 µmol g−1 h−1) than only using bare Co3O4 (∼178 µmol g−1 h−1) owing to bandgap reduction down to 1.71 eV and suppression of charge recombination. The dose control of 2.5 gL−1 has augmented the H2 generation to 3.095 mmol g−1 h−1 with a significant regeneration to reach 96.5 % after the fifth run. The improved performance of the formed 9.0 % Bi2S3/Co3O4 heterojunction is accredited to the enhanced photocharge separation between Bi2S3 and Co3O4.