2021/06/11 by Lei Chen, Zhi Yang, Baoliang Chen
Energy · Engineering · Materials Science · #Advanced Photocatalysis Techniques #Perovskite Materials and Applications #Quantum Dots Synthesis And Properties
paper · doi:10.1021/acs.energyfuels.1c00688
Loading transition metal as a cocatalyst to a photocatalyst is a promising and mainstream way to improve the photocatalytic H 2 evolution reaction (HER) of a semiconductor. However, transition metal cocatalysts are rarely reported to enhance photocatalytic oxygen reduction (ORR) to generate H 2 O 2 . In this work, a light-induced deposition approach was adopted to precisely load nickel sulfide nanodots onto the surface of g-C 3 N 4, and the resultant composite photocatalysts enhanced both photocatalytic HER and ORR performances. In the typical case of NiS@g-C 3 N 4, NiS@g-C 3 N 4 -30 displayed a H 2 evolution rate of 3297 μmol g –1 h –1 under visible-light irradiation, which showed 74 and 1.23 times activity for pure g-C 3 N 4 and classical Pt (3%) modified g-C 3 N 4, respectively. NiS@g-C 3 N 4 -30 also exhibited the best photocatalytic efficiency with a H 2 O 2 production of 400 μM in 1 h, which was 12.6 times that of pure g-C 3 N 4 . The remarkable activity and stability of this bifunctional catalyst can be attributed to the accurate loading of intimately contacted NiS nanodots at the electron transfer sites of g-C 3 N 4 nanosheets, which can boost the separation of photogenerated charge carriers and accelerate the chemical reaction on the surface of the photocatalyst. This work opens a new pathway for the precise preparation of bifunctional cocatalysts for solar to chemical energy conversion.