MOF-derived SnO2 nanoparticles for realization of ultrasensitive and highly selective NO2 gas sensing

Abstract

Herein, SnO2 nanoparticles (NPs) were synthesized from a Sn-metal organic framework (MOF) through a hydrothermal synthesis approach for NO2 sensing studies. The expected phase, morphology and composition of the SnO2 NPs were demonstrated via different characterizations. The individual sizes of SnO2 NPs were ∼20–30 nm, and they had a high surface area (185.31 m2/g). The sensing properties were measured at various temperatures towards NO2 gas. It showed very high responses of 240.60 and 3984.98–10 and 100 ppm NO2, respectively, at 200°C. Also, it still displayed a high response of 47.11–100 ppm NO2 gas at 25°C. Enhanced response of MOF-derived SnO2 NPs gas sensor was owing to the high surface area of the SnO2 NPs, the presence of oxygen vacancies, formation of plenty of SnO2-SnO2 homojunctions and the creation of SnO/SnO2 heterojunctions. The synthesis method employed in this study led to the preparation of high surface area SnO2 NPs that can be used for preparing other metal oxides for the development of sensors.