Enhanced Gas Sensing Performance of ZnO/TiCT MXene Nanocomposite.

A representative of titanium carbide MXene, TiCT is a promising candidate for high performance gas sensing and has attracted significant attention. However, MXene naturally has a multilayer structure with low porosity, which prevents its gas-sensing activity. Zinc oxide (ZnO) has long been utilized as a gas detector. Despite its good response to multiple gases, high operation temperature has limited its widespread use as a gas-sensing material. In this study, a room-temperature toxic gas sensor was prepared from ZnO/TiCT MXene nanocomposite consisting of 2D few-layered MXene and 1D ZnO nanoparticles. A simple technique for synthesizing the nanocomposite was established. The physicochemical properties of the nanocomposite were fine-controlled with more active sites and higher porosity. The sensitivity and gas-selectivity of the sensing material were closely examined. The nanocomposite showed enhanced response and recovery behaviors to toxic gases, which outperformed pure TiCT MXene and pure ZnO. This study offers a practical strategy by which to increase the gas-sensing performance of TiCT MXene, and expands comprehensive understanding of the gas-sensing process of ZnO/TiCT p-n heterostructure.