Adsorption of DTC-CTS on sphalerite (1 1 0) and Cu-activated sphalerite (1 1 0) surfaces: A DFT study

Abstract

Density functional theory (DFT) was used to simulate the adsorption of dithiocarbamate chitosan (DTC-CTS) on sphalerite (110) and Cu-activated sphalerite (110) surfaces in the presence and absence of water molecules. The results show that the adsorption of DTC-CTS on sphalerite (110) and Cu-activated sphalerite (110) surfaces in the absence of water are physical adsorption and chemical adsorption, respectively. It indicates that the adsorption capacity of DTC-CTS on sphalerite surface is enhanced obviously after being activated by Cu. That’s because DTC-CTS is easier to adsorb on Cu. Besides, the replacement of Zn by Cu on sphalerite (110) surface further enhanced the adsorption ability of DTC-CTS onto S of sphalerite surface. However, the presence of water molecules has little effect on the adsorption of DTC-CTS on sphalerite (110) and Cu-activated sphalerite (110) surfaces. The results of Density of states (DOS) and Mulliken population analysis also confirmed that the adsorption of DTC-CTS on Cu-activated sphalerite (110) surface is easier and more stable than that of sphalerite (110) surface.