The adsorption performance of harmful gas on Cu doped WS2: A first-principle study

Abstract

With the development of modern industry, the production of harmful gases brought about by the growth of industrial production will increase, seriously endanger human health, and will also cause pollution to the environment. The development of high-performance sensing materials to detect harmful gases has become an urgent problem to be solved in today's society. Based on the first-principles study, this paper analyzed the most stable doping points of Cu atom on the WS2 surface, and then calculates and compares the adsorption energy, charge transfer, adsorption distance and other parameters. At the microscopic level, we analyzed in detail the interaction between Cu doping WS2 (Cu-WS2) and four harmful gases (CO, CO2, NO, NO2). In addition, the sensing behavior of each gas molecule to the four gases was further evaluated by estimating the time required to remove each gas molecule from the surface of Cu-WS2. The results show that Cu atom tend to be located on top of the W atom and lead to a strong n-type doping, which will lead to an increase in the conductivity of WS2. Under certain conditions, high response and reasonable recovery time indicate that Cu-WS2 has ideal sensing behavior for CO and NO gases, while the very short recovery time indicates that Cu-WS2 was not suitable for detecting CO2 in actual engineering, and for NO2 gas, larger adsorption energy makes Cu-WS2 more suitable for gas scavenger. This work shows that Cu-WS2 is expected to become a new gas warning material or adsorption material for the detection and removal of harmful gases.