Microwave plasma processing of Ag2Zr4 nanospheres@GO composite: A novel approach of improving structural and photocatalytic properties

Low-pressure microwave plasma has attracted much attention as an effective strategy for improving the opto-physical properties of materials. In present study, Silver Zirconate nanospheres (Ag2Zr4) and its composite with Graphene Oxide (Ag2Zr4@GO) were synthesized hydrothermally for photodegradation of Basic Fuchsin (BF) dye. The Ag2Zr4@GO composite was subjected to oxygen plasma sustained by microwave source to improve the opto-physical properties. The physico-chemical attributes of samples were explored using conventional and analytical techniques. X-ray diffraction analysis revealed that plasma treated composite (PT-Ag2Zr4@GO) retained tetragonal crystalline system with crystallite size of 80 nm. Scanning electron microscopy with energy-dispersive X-ray spectroscopy reflected an increase in surface porosity of Ag2Zr4@GO composite after plasma treatment with an average particle size of 220 nm. The successful loading of Ag2Zr4 nanospheres onto GO surface was revealed by Fourier transform infrared spectroscopy. UV–visible spectroscopy exhibited the characteristic absorption bands of catalysts in 400–530 nm range. Dynamic light scattering analysis showed the z-average of 230 ± 5 nm with zeta potential of −14.01 ± 2 mV for PT-Ag2Zr4@GO composite. The parametric study exhibited 84, 91 and 99 % BF dye degradation under optimum conditions of pH = 6, dye dose = 10 mg/L, catalyst dose and irradiation time = 15 mgL−1/90 min, 10 mgL−1/60 min and 3 mgL−1/45 min for Ag2Zr4, Ag2Zr4@GO and PT-Ag2Zr4@GO composites, respectively. Kinetic study revealed that experimental data were in good agreement with Behnajady-Modirshahla-Ghanbery (BMG) model. Furthermore, photodegradation analysis of industrial wastewater exhibited a reduction of 75.63 % in chemical oxygen demand (COD) using PT-Ag2Zr4@GO composite. Reusability study revealed that catalysts can be reused in 5 consecutive cycles. Samples exhibited efficient antibacterial activity against E. coli and S. aureus strains and less cytotoxicity. All these merits demonstrate that PT-Ag2Zr4@GO composite can be used as a promising candidate for oxidation of organic pollutants in environmental remediation applications. [Display omitted] •Synthesis of bimetallic silver zirconate nanoparticles-based graphene oxide composite and its plasma treatment•Comparison study for treated and untreated plasma was performed•Photocatalytic degradation experiments revealed excellent catalytic efficiency of composites against Basic fuchsin dye•Comp