Room-temperature ammonia gas sensing via Au nanoparticle-decorated TiO2 nanosheets

Abstract

AbstractA high-performance gas sensor operating at room temperature is always favourable since it simplifies the device fabrication and lowers the operating power by eliminating a heater. Herein, we fabricated the ammonia (NH3) gas sensor by using Au nanoparticle-decorated TiO2nanosheets, which were synthesized via two distinct processes: (1) preparation of monolayer TiO2nanosheets through flux growth and a subsequent chemical exfoliation and (2) decoration of Au nanoparticles on the TiO2nanosheets via hydrothermal method. Based on the morphological, compositional, crystallographic, and surface characteristics of this low-dimensional nano-heterostructured material, its temperature- and concentration-dependent NH3gas-sensing properties were investigated. A high response of ~ 2.8 was obtained at room temperature under 20 ppm NH3gas concentration by decorating Au nanoparticles onto the surface of TiO2nanosheets, which generated oxygen defects and induced spillover effect as well.