A novel dual-channel ZnIn2S4/Bi4Ti3O12 S heterojunction significantly enhances photocatalytic hydrogen peroxide synthesis

Photocatalytic synthesis of hydrogen peroxide is an emerging topic for solar-to-chemical energy conversion. ZnIn 2 S 4 /Bi 4 Ti 3 O 12 (ZIS/BTO) - based S-scheme heterojunction semiconductor photocatalysts were prepared via a one-pot water bath method. Under visible light irradiation, the optimum H 2 O 2 yield of ZIS/BTO-2 reaches 1102 µmol L −1 , which is 20.0 and 11.5 times higher than those of the pure phases of Bi 4 Ti 3 O 12 and ZnIn 2 S 4 , respectively. Experimental and density functional theory (DFT) calculations demonstrated that the Built-in Electric Field (IEF) present between the ZIS/BTO S-type heterostructures not only facilitated the transfer of photogenerated carriers to surface active sites, but also promoted the adsorption of molecular oxygen and the tuning of the energy band structure. This resulted in an enhancement of the efficiency of photocatalytic oxygen reduction reaction (ORR) and the water oxidation reaction (WOR) for the synthesis of H 2 O 2 . Hence, the present study provided a practical route for the efficient synthesis of H 2 O 2 over Bi 4 Ti 3 O 12 - based photocatalysts and disclosed the reaction mechanism, that is, a heterojunction with a high efficiency for H 2 O 2 synthesis.