Highly active and porous single-crystal In2O3 nanosheet for NO:X gas sensor with excellent response at room temperature

Abstract

Porous single-crystal In2O3 nanosheet (ps-In2O3 NS) was designed and prepared through a method of calcination after liquid reflux. Compared with the other In2O3 with different surface morphologies, the ps-In2O3 NS has gas sensing properties towards NOx at room temperature. Gas sensing data strongly demonstrate that this porous single-crystal In2O3 nanosheet exhibits a distinguished response (89.48) and fast response time (16.6 s) to 97.0 ppm NOx. Meanwhile, the ps-In2O3 NS sensor presents a favorable linearity and good selectivity, and the detection of NOx is down to ppb levels at room temperature. The enhancement of the sensing response is attributed to the porous, single-crystal and two dimensional nanosheet structure of the synthesized ps-In2O3 NS, which has much higher BET surface area, effective gas diffusion of slit pores and thus provides more active sites for the reaction of NOx with surface-adsorbed oxygen ions. This work would be important for the low-cost and high performance of the In2O3 material with highly promising applications in gas sensors.