Polypeptide-Regulated the Self-Assembled In2O3/ZnO Nanocubes for Enhanced H2 Gas Sensing at Low Operating Temperatures

Abstract

In this study, hydrogen sensors based on In ₂ O ₃ /ZnO nanocubes are fabricated by single step hydrothermal route, and polypeptide is utilized to guide the morphology of the composites to heighten the responsiveness of the sensors to hydrogen at low operating temperatures. A series of analyses and validations are carried out by characterization techniques. Gas sensitivity test results display that the optimal operating temperature of the modified sensing element is reduced by 60 °C compared to the initial element, accompanied by a doubling of the response value (22.12). At the same time, the response time to 100 ppm H ₂ is 2.5 s. Even more strikingly, the modified gas sensing element has evidently improved the response speed to low-ppm levels hydrogen. Moreover, the sensor components exhibit favorable repeatability, stability and excellent selectivity. By analyzing the characterization data and gas-sensitive test results, the improved responsiveness of the sensing elements is mainly attributed to the synergistic effect of the dilatation in the specific surface area of the gas-sensitive materials and the increase in intergranular contacts.