Engineering surfaces to improve xylene gas sensing performance in ZnCo2O4 porous architectures

The surface states of gas sensing materials based on oxide semiconductors are closely related to their sensing dynamics. In this work, using surface engineering, p-type ZnCo2O4 architectures are prepared through a feasible hydrothermal strategy followed by subsequent annealing treatment and are applied for the detection of inert xylene gas. The as-prepared ZnCo2O4 architecture (ZCO-300) exhibits a higher response and selectivity toward xylene gas at a working temperature of 170 degrees C. Moreover, the ZCO-300 sensor also presents superior stability/reliability, good moisture resistance and a low detection limit of 0.1 ppm. The larger number of oxygen vacancy defects and higher specific surface area in ZCO-300 not only promote the catalytic oxidation of xylene gas by p-type semiconductor ZnCo2O4, but also provide more gas adsorption sites and surface reaction sites on sensing material surfaces, thereby endowing ZCO-300 with superior xylene gas sensing properties.