DFT Study on the Enhanced Sensing Performance of MoTe₂ Modified with Four Metals for Industrial Toxic Gases

With the acceleration of industrialisation, the emissions of harmful gases generated by industrial production have significantly increased, posing a serious threat to the environment and human health. This study employs density functional theory to compare the adsorption mechanisms and efficiency differences between ordinary metal-doped and noble metal-doped MoTe₂ monolayers for three industrial harmful gases (H₂S, HCN, and NO₂), aiming to explore dopant metal options that are both highly sensitive and cost-effective. The results show that precious metal doping significantly enhances the adsorption capacity and charge transfer efficiency of MoTe₂ towards toxic gases. Furthermore, Cr Ru significantly increases the density of electronic states and conductivity, thereby improving the sensitivity of gas sensing. Under high-temperature conditions, Ni and Cr doping enhance MoTe₂'s excellent sensing performance for hydrogen cyanide (HCN) and hydrogen sulphide (H₂S), similar to noble metals, while also demonstrating a strong adsorption capability for nitrogen dioxide. This study provides theoretical support for developing gas sensors, particularly by enhancing the response to toxic gases, making more cost-effective metal doping strategies possible.