Engineering the electronic structure of two-dimensional MoS2 by Ni dopants for pollutant degradation

The advanced oxidation process of peroxymonosulfate mediated through metal-doped MoS2 catalysts has attracted extensive attention in recent years, while the understanding of structure-performance relationship with the doping component and MoS2 is still challenging but highly desirable. In this work, a stable Ni-doped 2H-MoS2 catalyst was prepared via a simple one-step hydrothermal method, and employed as efficient PMS activators for the degradation of sulfamethoxazole (SMX). It is revealed that the degradation rate of 2%Ni doped 2H-MoS2 catalyst for SMX can achieve 93% within 60 min, which was 1.5 times than that of counterpart (2H-MoS2). A series of in-depth characterizations and DFT calculations revealed that the introducing of Ni greatly enhanced the generation of hydroxyl radicals, decreased the adsorption energy barriers for PMS and dramatically accelerated the reaction efficiency. Besides, a more stable structure and a higher cycling stability during reaction were obtained after Ni doping on the 2H-MoS2. Based on the results of systematic study, this work elucidates a fundamental understanding of structure-activity relationship on doping MoS2 catalysts, and provides a new strategy for the construction of efficient PMS activators.