Platinum Nanoclusters-Modified Porous In2O3 Nanocubes for Highly Sensitive and Selective Formaldehyde Gas Sensing at Room Temperature

Abstract

The detection of formaldehyde gas generally requires a relatively high temperature. It is still challenging to simultaneously possess high sensitivity and strong selectivity for the detection of low-concentration formaldehyde at room temperature. The activation energy of the reaction can be reduced by introducing oxygen vacancies or loading the metal clusters on the surface of metal oxide-based semiconductors, leading to an improvement in the performance and detection limit of the sensor. However, this approach may lead to an increased cross-sensitivity to other gases and a reduction in the selectivity of the sensors. In this study, In2O3 can capture a significant amount of adsorbed oxygen by increasing the oxygen vacancies and introducing platinum nanoclusters on the surface of In2O3 synthesized with a specific morphology, leading to high sensitivity and selectivity for the detection of formaldehyde gas at room temperature. The Pt-In2O3 sensor exhibits a response value of approximately 38 to a concentration of 1 ppm formaldehyde gas at 20 °C. Moreover, the developed sensor demonstrates excellent performance in a complex atmosphere and exhibits good long-term stability. The achieved high sensitivity and selectivity for the detection of formaldehyde gas at low temperatures hold significant implications for research and practical applications in the field of sensors.