Enhanced Photocatalytic Activities of RhB Degradation and H2 Evolution from in Situ Formation of the Electrostatic Heterostructure MoS2/NiFe LDH Nanocomposite through the Z-Scheme Mechanism via p-n Heterojunctions.

Abstract

Designing of an efficient heterostructure photocatalyst for photocatalytic organic pollutant removal and H2 production has been a subject of rigorous research intended to solve the related environmental aggravation and enormous energy crises. Z-scheme-based charge-transfer dynamics in a p-n heterostructure could significantly replicate the inherent power of natural photosynthesis, which is the key point to affect the transportation of photoinduced exciton pairs. In this finding, a series of p-type MoS2 loaded with n-type NiFe-layered double hydroxide (LDH) forming a heterostructure MoS2/NiFe LDH were designed by electrostatic self-assembled chemistry and an in situ hydrothermal strategy for photocatalytic rhodamine B (RhB) dye degradation and H2 production. The creation of p-n heterojunctions of type-II and Z-scheme mode of charge transfer modified the optical and electronic property of the as-synthesized MSLDH3, thereafter promoting the generation, separation, and migration of photoinduced electron-hole pairs. The as-synthesized MSLDH3 showed superior photocatalytic activities in degradation of RhB with H2 evolution, which was enhanced by 3- and 4.5-fold and 10.9 and 19.2 times higher than that of NiFe LDH and MoS2, respectively. Last but not the least, heterostructure MSLDH3 possesses practical stability for its resultant enhanced photocatalytic activity with recyclability for everyday life.