Synergistic effects of multiple heterojunctions significantly enhance the photocatalytic H_2 evolution rate CdS/La_2Ti_2O_7/NiS_2 ternary composites

摘要

Novel CdS/La2Ti2O7/NiS2 ternary composite photocatalysts without noble metal were successfully constructed by a simple hydrothermal method. Under visible light irradiation (lambda 400 nm), the optimal CdS/La2Ti2O2/NiS2 composite produced H-2 at a rate of about 12.77 mmol g(-1) h(-1), which was 84 times as high as that of pure CdS. This performance enhancement can be attributed to the formation of multiple heterojunctions (including CdS/NiS2, CdS/La2Ti2O7 and CdS/La2Ti2O2/NiS2 interface structures) between the three components in the as-prepared CdS/La2Ti2O2/NiS2 composites. The formed multiple heterojunctions help to separate electron-hole pairs more quickly and efficiently, thus greatly increasing the photocatalytic activity of the CdS/La2Ti2O2/NiS2 composites. This is very important for the utlization of solar energy for water splitting. (C) 2019 Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.