Hierarchical flower-like TiO2 microspheres for high-selective NH3 detection: A density functional theory study

Abstract TiO2 is proved to be a promising material in the detection of various hazardous gases at the high temperature. However, gas adsorption-diffusion capacity at the room temperature is limited by their insufficient specific surface area and surface active sites. Herein, we report a strategy to synthesis of flower-like TiO2 microspheres assembled by nanosheets and characterize the selective adsorption of NH3 by using density functional theory (DFT). The as fabricated flower-like TiO2 microspheres show an outstanding gas sensitivities (∼122 to 50 ppm NH3) and high selectivity for NH3 detection at room temperature. The higher adsorption energy and smaller adsorption distance of NH3 on TiO2 (001) indicate the much stronger interaction NH3-TiO2 system. The present studies provide useful gas sensing materials with fine morphologies for the development of high-performance room temperature NH3 sensors.