NiO-functionalized In2O3 flower-like structures with enhanced trimethylamine gas sensing performance

NiO-functionalized In2O3 flower-like structures were successfully synthesized via a simple one-step hydrothermal route and applied in gas sensors for trimethylamine (TMA) detection. By virtue of the unique 3D hierarchical flower-like structures, p-n heterojunctions and the catalytic activity of NiO, NiO-functionalized In2O3 shows enhanced TMA gas sensing performance. Specifically, the sensor fabricated from 0.05-NiO-In2O3 composites with well-defined flower-like structures shows the highest response of about 20.5 to 10 ppm TMA at 200 °C, which is 4.7 times higher than that of the pure In2O3 flower-like structures (4.4 to 10 ppm TMA). Besides, this sensor shows good reproducibility and stability, high selectivity and a ppb-level detection limit of 1.5 to 0.5 ppm (500 ppb) TMA, providing a widely applicable strategy to improve the gas sensing properties of metal oxides semiconductors.