Porous In2O3 nanospheres with high methane sensitivity: A combined experimental and first-principle study

Abstract

Sensors that can detect methane (CH4) at low or even room temperature with good sensitivity and selectivity are of great significance for practical applications. Herein, porous In2O3 nanospheres (NSs) sensitive materials was synthesized the via a one-step hydrothermal method to detect CH4 sensitively and selectively at 30 °C. The obtained porous In2O3 NSs sensor possesses high sensitivity to CH4, which is 15.9–500 ppm CH4 at 30 °C. Moreover, the sensor has good selectivity, repeatability and long-term stability. The excellent sensing performance of porous In2O3 NSs sensor towards CH4 could be attributed to its unique structural characteristics. Simultaneously, to gain insight into the gas sensing mechanism of CH4 in the sensor, the first principle study of In2O3 was carried out based on density functional theory. The calculated results agree with the conclusions obtained from the experiment that In2O3 has better gas sensitivity and selectivity to CH4, and further proves that the sensitive mechanism of In2O3 to methane is controlled by the surface adsorbed oxygen model. All the conclusions show that porous In2O3 NSs sensor has a very promising application prospect for CH4 detection at room temperature.