Synergy Photodegradation of Basic Dyes by ZnO/Bi۲O۳ Nanocomposites under Visible Light Irradiation

Environmental problems caused by organic pollutants can be resolved by semiconductor photocatalysts. Using the strategies of doping hydrothermally, Zinc oxide/Bismuth oxide nanocomposites (ZnO/Bi۲O۳ NCs) comprising of different proportions of BiO for the applications of basic dyes and were tested for antibacterial activity. The average crystallite sizes of these, metal oxide nanocomposites were ranging from ۱۲ nm to ۲۹ nm. UV-Visible diffuse reflectance spectra were used to determine the optical energy bandgap (Eg) of about ۲ to ۲.۸۲ eV of the NCs for different proportions of the metal oxides. Square-like morphology of ZnO NPs and ZnO/Bi۲O۳ NCs were observed in the Scanning Electron Microscopy (SEM). This morphological structure along with its high surface area attributes to the promotion of degrading organic pollutants in dyeing wastewater along with decolorization. The Photoluminescence (PL) emission intensity of ZnO/Bi۲O۳ NCs suggests a lower recombination rate of photogenerated charge carriers leading to enhanced photocatalytic activity. Visible light-driven photodegradation of MB, MG, and R۶G by ۰.۵M ZnO: ۰.۵M Bi۲O۳ resulted in high rate constants of ۸.۵×۱۰-۳/min, ۶×۱۰-۳/min, and ۹×۱۰-۳/min. The hybrid ZnO/Bi۲O۳ NC materials showed immense antibacterial activity against gram-positive bacterium S. aureus and the gram-negative bacterium E. coli with an inhibition zone of ۶mm and ۵mm respectively which was comparable to the standard, chloramphenicol. A desired predominant gram-positive bacterial inhibition unwraps a new way for enhanced antibacterial agents. The heterojunction at the interface between Bi۲O۳ and ZnO could efficiently reduce the recombination of photoinduced electron-hole pairs and thereby enhancing the photocatalytic and antibacterial activity of ZnO/Bi۲O۳ heterostructures. This study reveals that ZnO/Bi۲O۳ NCs as a promising candidate for the photocatalytic and antibacterial treatment of dye effluent.

کلیدواژه ها:

ZnO/Bi۲O۳ nanocomposites ، X-ray diffraction ، energy bandgap ، Photoluminescence ، photocatalytic activity ، Antibacterial activity