High performance room temperature NH3 sensor based on zigzag morphology TiO2/Fe2O3 heterojunction

The paper discusses the optimization of gas sensor performance using heterojunctions and nanostructure morphology modulation. It specifically focuses on TiO2/Fe2O3 heterojunction combinations based on sawtooth shaped nanostructures prepared using an electron beam evaporation method. The study explores an optimization scheme for enhancing NH3 sensing performance of TiO2 at room temperature. Various sawtooth shaped TiO2/Fe2O3 nanorod arrays with different material ratios and deposition orders were prepared and characterized using scanning electron microscopy and X-ray diffraction. Gas sensing tests including NH3 concentration gradient, repeatability, and selectivity were conducted at room temperature. The results show that the gas sensing performance varies with different material ratios in the heterojunction combinations. The combination where TiO2 is deposited in the lower layer at three times the height of Fe2O3 outperformed other combinations in NH3 room temperature sensing, showing significant improvement compared to pure TiO2 materials. The study also explores the impact of humidity on the sensor's performance at room temperature.