Crystalline zinc sulfide (ZnS) thin films were prepared by chemical bath deposition (CBD) using the mixed aqueous solutions of zinc acetate, thiourea and tri-sodium citrate, where tri-sodium citrate was used as the complexing agent. The thin films were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM) and optical absorption. The as-deposited thin films were surface homogeneous with pure wurtzite structure and the optical band gap of the film was estimated to be 3.53 eV.

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Two CeO 2 catalysts were fabricated by dry ball milling in the absence or presence of organic ligand, denoted as CeO 2 -A and CeO 2 -B, respectively, and tested for selective catalytic reduction of NO by NH 3 (NH 3 -SCR). It was found that the CeO 2 -B catalyst exhibited high NH 3 -SCR activities as well as high SO 2 and H 2 O resistance. The characterizations of nitrogen adsorption (BET), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG), Raman spectroscopy, temperature-programmed reduction (H 2 -TPR), temperature-programmed desorption (SO 2 -TPD) and X-ray photoelectron spectroscopy (XPS) revealed that the addition of adipic acid in the synthetic procedure leaded to a high reducibility of cerium species and a special surface microstructure, including relative high surface defects and hierarchical pore structure of the CeO 2 catalyst, which played important roles in enhancing NH 3 -SCR performance. Meanwhile, the interaction between SO 2 and CeO 2 under different condition was investigated in detail by in situ diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) and SO 2 -TPD. The data suggested that the high resistance to SO 2 poisoning of CeO 2 -B could be explained by a low amount of sulfur species formation and a low speed transformation of sulfites to sulfates on the ceria catalyst due to its special surface microstructure.