Synthesis and characterization of BiOCl–Cu2ZnSnS4 heterostructure with enhanced photocatalytic activity

Abstract

Cu 2 ZnSnS 4 QDs (5-7 nm) were synthesized by chemical coprecipitation route. Using prepared Cu 2 ZnSnS 4 QDs, a new type of BiOCl-Cu 2 ZnSnS 4 heterostructures were prepared using bismuth nitrate as a precurssor and potassium chloride as a source of chlorine at 100 °C, 4 h. BiOCl-Cu 2 ZnSnS 4 heterostructures were analyzed by XRD, TEM, UV-visible NIR, PL and surface area studies. The diffracted peaks of BiOCl-Cu 2 ZnSnS 4 heterostructure show the presence of tetragonal BiOCl and did not show the intense peaks of Cu 2 ZnSnS 4 QDs. TEM images of BiOCl-Cu 2 ZnSnS 4 showed the deposition of Cu 2 ZnSnS 4 QDs on the BiOCl microsphere surface. The surface area of BiOCl, Cu 2 ZnSnS 4 and BiOCl-Cu 2 ZnSnS 4-1 was of 1.91 m 2 /g, 3.06 m 2 /g and 13.39 m 2 /g, respectively. BiOCl-Cu 2 ZnSnS 4-1 had a higher photodegradation rate for Congo red dye than BiOCl and Cu 2 ZnSnS 4 QDs under sunlight, and that higher photoactivity was due to the heterostructure effect between BiOCl and Cu 2 ZnSnS 4 QDs along with increased optical absorption in the visible region. Scavenger study endorses the involvement of superoxide and holes radicals in the degradation of Congo red.

Recent Advances in Efficient Photocatalytic Degradation Approaches for Azo Dyes

“…[205,206]. For superoxide anion radical (•O 2 − ), the scavengers used are p-benzoquinone (p-BQ) and ascorbic acid (AA) [207][208][209]. Te scavengers such as ethylenediaminetetraacetic acid (EDTA), triethanolamine (TEA), sodium oxalate (Na 2 C 2 O 4 ), and sodium iodide (NaI) are usually used to scavenge holes [210][211][212].…”