Oxygen defect-rich In2O3 thin film sensor via in-situ controllable assembly for enhanced detection of Cl2 under low power consumption

Synthesizing a gas-sensitive material for detecting Cl 2 at low temperatures remains a challenge in terms of lowering the operating temperature of the gas sensors. In this paper, a simple hydrothermal method was used to prepare thin film of MIL-68(In) nanoparticles grown in-situ on ceramic tubes and calcined to obtain an oxygen defect-rich In 2 O 3 sensitive thin film. At a low temperature of 50 °C, this In 2 O 3 thin-film sensor can achieve a response of 14.1–5 ppm Cl 2 , with a minimum detectable concentration of 100 ppb. The sensor has a clear advantage in terms of optimal operating temperature. In addition, the optoelectronic properties of the sensor, the types of adsorbed oxygen on the surface and the effect of oxygen defects are investigated in detail, and the density functional theory calculations were used to corroborate the actual characterization results with the theoretical calculation simulation results. It provides an in-depth analysis of the reasons for the excellent sensing performance of the sensor to chlorine.