Highly dispersed CeO2 nanocubics supported on hydrogen substituted graphyne sheets for highly NH3 gas sensing detection and humidity independent at room temperature

NH₃ is a fairly important raw material in a number of fields but harmful to the human. Currently, hydrogen substituted graphyne (HsGY) shows fast response to NH₃ gas based on our previous report. However, it still suffers from low response values and humidity interference. CeO₂ has the advantage of moisture resistance as NH₃ gas sensor but prone to agglomeration, whereas the alkyne bond of HsGY can anchor CeO₂ to form a discretely distributed CeO₂. Therefore, highly dispersed CeO₂ nanocubics anchoring on HsGY sheets are synthesized through hydrothermal method. The gas sensing characteristics show that the gas sensing response value to 80 ppm NH₃ is increased by 3 times compared to pure HsGY. Furthermore, they present relatively stable NH₃ gas response under relative humidity variation (20–80 %). In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) is used to reveal the gas sensing mechanism. Energy bands are analyzed using ultraviolet photoemission spectroscopy (UPS), revealing the improvement mechanism of NH₃ gas-sensitive performance. Density functional theory (DFT) calculations are employed to explain selectivity mechanism to NH₃ against other interference gases. Our research provides novel gas sensing materials for the development of high-performance, moisture-resistant room temperature NH₃ sensors.