Effect of M2+ (M = Zn and Cu) Dopants on the Electronic Structure and Photocatalytic Activity of In(OH)ySz Solid Solution

Nanocrystalline Zn-doped and Cu-doped In(OH)(y)S-z solid solutions were synthesized from In(NO3)(3), thiourea, and M(NO3)(2) (M = Zn and Cu) in an aqueous solution of ethylenediamine via a facile hydrothermal method. The samples were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (DRS), and X-ray photoelectron spectroscopy (XPS). Although both Zn-doped and Cu-doped In(OH)(y)S-z solid solutions show visible-light-driven photocatalytic activities in the decomposition of acetone and typical dye like RhB, their photocatalytic performance is quite different. Cu-doped In(OH,,S, solid solution can only decompose acetone and RhB to intermediates, but cannot mineralize them. On the contrary, Zn-doped In(OH),,S, solid solution can mineralize acetone and RhB to CO2 and its photocatalytic activity is a little enhanced compared to that of the undoped In(OH)(y)S-z. solid solution. Density functional theory (DFT) calculations on Zn-doped and Cu-doped In(OH)(y)S-z solid solutions reveal that the introduction of M2+ (M = Zn and Cu) into In(OH)(y)S-z solid solution influences the electronic structure. The different photocatalytic performance observed on Zn-doped and Cu-doped In(OH)(y)S-z solid solutions can be well explained by their different electronic structures.