Construction and DFT study of Pd decorated WSe2 nanosheets for highly sensitive CO detection at room temperature

This paper demonstrates a high-performance CO sensor based on Pd-decorated WSe2 (Pd-WSe2) hexagonal nanosheet nanostructures. The X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy were used to examine the hydrothermally prepared Pd-WSe2 nanofilms. When exposed to different concentrations of CO gas at room temperature, the gas sensing performance of the Pd-WSe2 thin film sensor was studied. The Pd-WSe2 thin film sensor had excellent sensing performance for CO gas, including high sensitivity, excellent repeatability, good selectivity and stability. Based on first-principles density functional theory (DFT), the sensing mechanism of Pd-WSe2 film to CO gas was discovered, and it was proved from a theoretical perspective that the sensing performance of precious metal Pd doping on CO was better than those of other metal doping. This paper confirmed that the Pd-decorated WSe2 hexagonal nanosheets were a good candidate for high-efficiency CO sensing.