Enhanced Sensing Performance of SnXTi1‐XO2‐TiXSn1‐XO2 Core–Shell Heterostructure via Increasing the Density of Unsaturated Sn and Ti Atoms

Abstract

AbstractThe strategy of combining different semiconductor materials is adjudged an effective approach to improve the sensing performances of semiconductor materials. However, the specific synergistic mechanism for the excellent gas‐sensitive performances of composite materials has not been elucidated. Herein, a facile solvothermal method is employed to synthesize SnXTi1‐XO2‐TiXSn1‐XO2 core–shell heterostructures using SnCl4•5H2O and tetrabutyl titanate (TBOT) as raw materials. When the molar ratio of SnCl4•5H2O/TBOT is 1.8/3.0, the afforded composite exhibited the highest gas sensing performances compared with other composites prepared with other molar ratios. The enhanced sensing performance is attributed to the simultaneous incorporation of Sn and Ti ions into each other's lattice, leading to an increase in the density of unsaturated Sn and Ti atoms on the surface. Ultimately, more oxygen vacancies are formed by the unsaturated Sn and Ti atoms, which benefits electron capture and the redox reaction of adsorbed gases. Thus, the concept of increased unsaturated metal atoms and oxygen vacancy resulting from the doping of different metal ions into each other's lattice has deepened the understanding of gas sensing and the catalytic reaction mechanisms. The lattice synergy of different metals provides a pathway for the design of advanced gas‐sensing materials and catalysts.