High sensitivity and ultra-low detection limit of chlorine gas sensor based on In2O3 nanosheets by a simple template method

Chlorine (Cl2) gas sensors with outstanding gas response and ultra-low detection limit by an easy and economical fabrication are increasingly in demand in practical application. In this work, In2O3 nanosheets with excellent gas sensing properties for Cl2 have been successfully synthesized using melamine-formaldehyde (MF) sponge as the template via a simple soak-drying-calcination approach. The gas response (Rgas/Rair) of In2O3 nanosheets sensor is up to 2353.4 toward 3 ppm Cl2 at 200 °C, which is about 158 times compared with In2O3 particles (14.9). The selectivity to Cl2 reaches up to 254.3 against other interferential gases. Additionally, the sensor based on In2O3 nanosheets displays extremely low detection limit of 0.037 ppb. Such excellent gas sensing performance is primarily ascribed to the unique sheet structure and abundant oxygen vacancies which are formed during the removal of MF sponge template. Therefore, the In2O3 nanosheets sensor shows great potential in Cl2 detection.