Room-temperature ammonia gas sensing via Au nanoparticle-decorated TiO2 nanosheets
Jeong Yun Hwang, Yerin Lee, Gyu Lee, Seung Yong Lee, Hyun‐Sik Kim, Sang‐il Kim, Hee Jung Park, Sun-Jae Kim, Beom Zoo Lee, Myung Sik Choi, Changhyun Jin, Kyu Hyoung Lee
Abstract
Abstract A 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 (NH 3 ) gas sensor by using Au nanoparticle-decorated TiO 2 nanosheets, which were synthesized via two distinct processes: (1) preparation of monolayer TiO 2 nanosheets through flux growth and a subsequent chemical exfoliation and (2) decoration of Au nanoparticles on the TiO 2 nanosheets via hydrothermal method. Based on the morphological, compositional, crystallographic, and surface characteristics of this low-dimensional nano-heterostructured material, its temperature- and concentration-dependent NH 3 gas-sensing properties were investigated. A high response of ~ 2.8 was obtained at room temperature under 20 ppm NH 3 gas concentration by decorating Au nanoparticles onto the surface of TiO 2 nanosheets, which generated oxygen defects and induced spillover effect as well.