Ag modified Tb-doped double-phase In2O3 for ultrasensitive hydrogen gas sensor

Herein, an Ag modified Tb-doped In2O3 nanocomposite with two coexisting crystalline phases was synthesized by hydrothermal and annealing methods. The gas-sensing performance test results revealed that the In2O3 composite with two coexisting crystalline phases improves the stability and accuracy of the sensor compared to In2O3 with only a cubic phase. Moreover, Ag modified Tb-doped In2O3 sensor not only has an excellent response to hydrogen (H-2) of ppb level (4.63 for 500 ppb H-2) but also greatly improves the selectivity, stability, and reliability of the H-2 sensor at a low optimal operating temperature. The coexistence of the two crystal phases enhances the stability of the sensor materials and the introduction of oxygen vacancies and the spillover effect by Tb doping and Ag modification enhances the gas-sensing performance. In particular, the synergistic effect of Ag modification and Tb doping also reduces the response attenuation effect during H(2 & nbsp;)reaction process. The gas sensing mechanism of the prepared sensor provides an effective strategy to achieve an excellent gas-sensing performance for H-2 gas.