Metal-free SiOC/g-C3N4 heterojunction composites with efficient visible-light photocatalytic H2 production

Photocatalytic water splitting to product hydrogen (H 2 ) is a desired route to utilize solar energy into chemical energy. At present, most photocatalysts for H 2   generation contains metallic elements with high-cost, confined reserves, and environmentally   unfriendly. The exploitation of metal-free and efficient photocatalysts becomes   particularly   important. Herein, a new metal-free g-C 3 N 4 -based heterojunction composites were facilely produced via the ultrasonic assisted deposition and subsequent calcination from g-C 3 N 4 layers embedded with SiOC with prominent conductivity and large surface area. Systematic investigates suggested that the SiOC/g-C 3 N 4 heterojunctions exhibited eminently meliorated photocatalytic H 2 production efficiency. The optimum H 2 production rate (1020 μmol h −1 g −1 ) of the SiOC/g-C 3 N 4 photocatalyst is 3.2 and 25.5 folds that of g-C 3 N 4 and SiOC , respectively. The boosted photocatalytic activity primarily originates from the increased absorptivity of light, the markedly expedited charge migration and the impeded recombination of charge carriers. This study offers a new perspective for the scientific contrive and fabrication of high-quality heterojunction photocatalysts for solar energy utilization.