Remarkably Enhanced Methane Sensing Performance at Room Temperature via Constructing a Self-Assembled Mulberry-Like ZnO/SnO2 Hierarchical Structure

Abstract

Development of metal oxide semiconductors-based methane sensors with good response and low power consumption is one of the major challenges to realize the real-time monitoring of methane leakage. In this work, a self-assembled mulberry-like ZnO/SnO2 hierarchical structure is constructed by a two-step hydrothermal method. The resultant sensor works at room temperature with excellent response of ~56.1% to 2000 ppm CH4 at 55% relative humidity. It is found that the strain induced at the ZnO/SnO2 interface greatly enhances the piezoelectric polarization on the ZnO surface and that the band bending results in the accumulation of chemically adsorbed (Formula presented.) ions close to the interface, leading to significant improvement in the sensing performance of the methane gas sensor at room temperature.