Synergistic effects of multiple heterojunctions significantly enhance the photocatalytic H2 evolution rate CdS/La2Ti2O7/NiS2 ternary composites

Abstract

Abstract Novel CdS/La2Ti2O7/NiS2 ternary composite photocatalysts without noble metal were successfully constructed by a simple hydrothermal method. Under visible light irradiation (λ\xa0>\xa0400\xa0nm), the optimal CdS/La2Ti2O7/NiS2 composite produced H2 at a rate of about 12.77\xa0mmol\xa0g−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/La2Ti2O7/NiS2 interface structures) between the three components in the as-prepared CdS/La2Ti2O7/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/La2Ti2O7/NiS2 composites. This is very important for the utlization of solar energy for water splitting.