XO2 (X=Ti, Zr, and Hf) nanoparticles modified SnS2 nanosheet for detection and scavenging towards NO2 and SO2

Abstract

Realizing industrial applications for online monitoring and scavenging of hazardous gases (SO2 and SO2) is essential. In this study, utilizing density functional theory (DFT), electronic characteristics of pristine SnS2 monolayers modified with transition metal oxides (TiO2, HfO2, and ZrO2) are examined as well as electrical characteristics and abilities to adsorb hazardous gases (NO2 and SO2). The conduction and valence band structures of the composite structures are ideally optimized, and the transition metal oxides can be reliably bonded to SnS2 monolayer in the form of perfect crystal modification. The transition metal oxides function as electron acceptors, taking electrons away from the SnS2 monolayer and accomplishing p-type modification. The stability of XO2 (X=Ti, Hf, and Zr) modification is TiO2 > ZrO2 > HfO2. With the significant larger adsorption energy for NO2 than for SO2 molecules, XO2-SnS2 (X=Ti, Hf, and Zr) has a superior adsorption effect to NO2. To achieve differentiated online monitoring and scavenging, various modified structures, adsorption systems, and LUMOHOMO with varying band gaps and conductivities will assist to increase the selectivity of gas sensitive materials for hazardous gases.