Adsorption and enhanced photocatalytic activity of the {0001} faceted Sm-doped ZnIn2S4 microspheres

• Published in: Journal of hazardous materials Vol. 278; pp. 572 - 583
• Main Authors: Tan, Congwei, Zhu, Gangqiang, Hojamberdiev, Mirabbos, Lokesh, Koodlur Sannegowda, Luo, Xiancong, Jin, Lei, Zhou, Jianping, Liu, Peng
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15-08-2014; Elsevier
• Subjects: Adsorption; Applied sciences; Azo Compounds - chemistry; Catalysis; Catalytic reactions; Chemical engineering; Chemistry; Coloring Agents - chemistry; Crystal facet; Doping; Exact sciences and technology; General and physical chemistry; Indium - chemistry; Indium - radiation effects; Light; Light irradiation; Microspheres; Photocatalysis; Photocatalytic activity; Photodegradation; Photolysis; Pollution; Reactors; Rhodamines - chemistry; Samarium - chemistry; Samarium - radiation effects; Separation; Sulfides - chemistry; Sulfides - radiation effects; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Visible light; X-ray photoelectron spectroscopy; Zinc - chemistry; Zinc - radiation effects; ZnIn2S4; Photocatalytic activity; Visible light; Crystal facet; Adsorption; ZnIn2S4; Scanning electron microscopy; Dyes; Microsphere; Pollutant behavior; Photocatalysis; Doping; Desorption; Ultraviolet radiation; Transmission electron microscopy; S; Morphology; Visible radiation; Znln; Photochemical degradation; ZnInS
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2014.06.019

•Sm-doped ZnIn2S4 microspheres were synthesized by hydrothermal method.•Sm-doped ZnIn2S4 microspheres are composed of nanoplates with {0001} facets exposure.•The negatively charged {0001} facets are beneficial for the adsorption of RhB.•ZnIn2S4 microspheres doped with 2% Sm shows the best visible-light photocatalytic activity.
In this study, the doping effect of samarium on the structure, morphology, adsorption and photocatalytic performance of hexagonal ZnIn2S4 microspheres was studied. The photocatalytic activity of Sm-doped ZnIn2S4 microspheres was evaluated for the photodegradation of Rhodamine B (RhB) and methyl orange (MO) under visible light irradiation. The samples were characterized by XRD, SEM, XPS, UV–vis, TEM, and N2 adsorption–desorption analysis. The results show that the hexagonal ZnIn2S4 microspheres are composed of nanoplates growing along c-axis with the predominant negative-charged S plane. Compared with the photodegadation of MO dye, the negative-charged {0001} facets not only are beneficial for the adsorption of RhB by –N(Et)2 groups but also can accumulate the separation of photogenerated electrons and holes, enhancing photodegradation efficiency by direct-hole photocatalysis. Moreover, Sm is partially substituted for In in the crystal lattice for forming the doping energy level which promotes the separation of photoinduced electron–hole pairs and enhances absorption of visible light. Hexagonal 2% Sm-doped ZnIn2S4 microspheres with exposed {0001} facets resulted in higher photodegradation efficiency of RhB under visible light irradiation.