1T and 2H mixed phase MoS2 nanobelts coupled with Ti3+ self-doped TiO2 nanosheets for enhanced photocatalytic degradation of RhB under visible light

Abstract

A novel 1T-2H MoS2/TiO2−x composite was fabricated via a facial hydrothermal and in-situ chemical reduction process, in which 1T and 2H mixed phase MoS2 (1T-2H MoS2) nanobelts were deposited on Ti3+ self-doped TiO2 (TiO2−x) nanosheets. This 2D-2D 1T-2H MoS2/TiO2−x composite exhibits excellent photocatalytic degradation performance toward RhB under visible light, which is much higher than that of pristine TiO2. The remarkably enhanced photocatalytic activity of 1T-2H MoS2/TiO2−x composite can be ascribed to the 2D heterostructure, Ti3+ and oxygen vacancy defects, which enhances the adsorption for pollutants, provides abundant reaction active sites, extends the photoresponse to visible light region, benefits the effective charge separation and transport. Furthermore, the experiment results showed that the metallic 1T phase MoS2 in 1T-2H MoS2/TiO2−x composite could effectively accelerate charge transfer between 2H phase MoS2 and TiO2−x, resulting in enhanced photocatalytic degradation ability. Moreover, a feasible photocatalytic reaction mechanism of 1T-2H MoS2/TiO2−x photocatalytic system was proposed in view of the active species trapping experiments, electron spin resonance tests and energy band analysis.