Gram-scale wet chemical synthesis of wurtzite-8H nanoporous ZnS spheres with high photocatalytic activity

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• 作者：Yong Liu^a ; Juncheng Hu^a ; ^{junchenghuhu@hotmail.com"" rel=""nofollow} ; Chilan Ngo^b ; Sergey Prikhodko^b ; Suneel Kodambaka^b ; ^{Kodambaka@ucla.edu"" rel=""nofollow} ; Jinlin Li^a ; Ryan Richards^c ; ^{rrichard@mines.edu"" rel=""nofollow}
• 关键词：Nanoporous ZnS spheres ; Wurtzite ; Photocatalysis ; Organic pollutants ; Hydroxyl radical ( ; //www.sciencedirect.com/scidirimg/entities/rad"" alt=""radical dot"" title=""radical dot"" border=""0"">OH) ; Photoluminescence technique
• 刊名：Applied Catalysis B: Environmental
• 出版年：2011
• 出版时间：21 July 2011
• 年：2011
• 卷：106
• 期：1-2
• 页码：212-219
• 全文大小：946 K

文摘

Wurtzite-8H nanoporous ZnS spheres assembled from crystallites, were synthesized via a “green” wet chemical route. A possible formation mechanism for the growth process of the ZnS spheres has been proposed based on experimental observations. The prepared catalysts are characterized by transmission electron microscopy, high-resolution transmission electron microscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, N₂ adsorption–desorption isotherms, elemental analysis, and UV–vis absorption spectroscopy. The catalyst showed high and stable photocatalytic activity for the degradation of persistent toxic organic pollutants, as demonstrated with azo dye X-3B (X-3B), trichloroacetate (TCA) and phenol under both visible (>420 nm) and UV light irradiation. The experimental results demonstrate that the photocatalytic activity of ZnS spheres is 3.3 and 9 times higher than that of Degussa P25 and commercial ZnS, respectively. The production of OH radicals on the ZnS surface was detected by the photoluminescence (PL) technique using coumarin as a probe molecule, which suggests that OH radicals are the dominant photo-oxidant in the photocatalytic reaction. More importantly, this synthesis method can be economical for a scale-up process, and may also be applicable to the preparation of additional II–VI semiconductors for catalysis and other applications.