A novel nanoparticles spilled-over In2O3microcubes-enabled sustainable chemiresistor for environmental carbon dioxide monitoring.

ABSTRACT

Achieving sustainable future energy goals includes enhancing renewable energy production, optimizing daily energy consumption using feedback loops and minimizing/monitoring contributions to atmospheric carbon dioxide (CO2). Developing economic next-generation CO2sensors enables local monitoring of industrial CO2emissions, aiding energy management and climate monitoring. This study elucidates the efficacy of CO2chemiresistor based on indium oxide (In2O3) micro cubes with spilled-over nanoparticles. The investigation primarily focuses on fabricating and optimising In2O3-based CO2chemiresistors utilizing a hydrothermal technique, creating porous micro cubes essential for enhanced CO2monitoring. As revealed by various characterization techniques, the minimum crystallite size was found to be 24.92 nm with optimum porosity and a high surface-to-volume ratio comprising spilled-over nanoparticle morphology. The fabricated chemiresistor demonstrated excellent CO2 sensing efficacy with a maximum response of around 4.1% at room temperature with selectivity, repeatability, and reversible sensing behavior. The sensing mechanism has been revealed, which is supported by theoretical density functional theory evaluations. Notably, the sensing results reveal the capability of In2O3-based sensors to detect CO2at low concentrations as low as ⩽10 ppm, which enables the chemiresistor for practical implementation in diverse sectors to achieve sustainability.