Synthesis and Evaluation of ZnFe2O4@Bi2WO6 Nanocomposites Enhanced with Graphene Oxide and Reduced Graphene Oxide: A Novel Approach for Sustainable Photocatalytic Degradation of Organic Pollutant

This study presents an innovative approach to synthesizing magnetically recoverable ZnFe<INF>2</INF>O<INF>4</INF>@Bi<INF>2</INF>WO<INF>6</INF>-GO and ZnFe<INF>2</INF>O<INF>4</INF>@Bi<INF>2</INF>WO<INF>6</INF>-rGO-decorated graphene oxide and reduced graphene oxide nanocomposites using swift and energy-conserving microwave-assisted methods. The synthesis of ZnFe<INF>2</INF>O<INF>4</INF>@Bi<INF>2</INF>WO<INF>6</INF> and ZnFe<INF>2</INF>O<INF>4</INF>@Bi<INF>2</INF>WO<INF>6</INF> nanocomposites was accomplished using a microwave-assisted combustion method at a low power setting of 200 W, completed in just 5 min with minimal glycine as the fuel source. Various characterization techniques were employed to analyze the obtained materials, including XRD, EDX, UV-DRS, PL, TEM, FESEM, FTIR, VSM, BET analysis, and UV-Visible spectroscopy. The microwave synthesis process produced GO/rGO surfaces that effectively facilitate electron transport within the photocatalysts. We optimized the photocatalytic performance of the catalysts by modifying the weight ratios of graphene oxide and reduced graphene oxide when evaluating their efficacy against tetracycline antibiotic under visible light irradiation. The presence of mesoporous structures significantly enhances the performance of the ZnFe<INF>2</INF>O<INF>4</INF>@Bi<INF>2</INF>WO<INF>6</INF>,ZnFe<INF>2</INF>O<INF>4</INF>@Bi<INF>2</INF>WO<INF>6</INF>-GO, and ZnFe<INF>2</INF>O<INF>4</INF>@Bi<INF>2</INF>WO<INF>6</INF>-GO photocatalysts. Among these photocatalysts, the highest photocatalytic activity was observed for ZnFe<INF>2</INF>O<INF>4</INF>@Bi<INF>2</INF>WO<INF>6</INF>-GO (0.10 g/L catalyst concentration and 10 mg/L dye concentration at pH = 5), achieving effective degradation in just 25 min under visible light. Kinetic studies revealed that the photodegradation of tetracycline adheres to a pseudo-first-order reaction model, with rate constants determined to be 0.210 min<SUP>-1</SUP> for ZnFe<INF>2</INF>O<INF>4</INF>@Bi<INF>2</INF>WO<INF>6</INF>-GO and 0.115 min<SUP>-1</SUP> for ZnFe<INF>2</INF>O<INF>4</INF>@Bi<INF>2</INF>WO<INF>6</INF>-rGO at a concentration of 0.10 g/L. This method of synthesizing nanocatalysts through microwave-assisted combustion represents a cost-efficient and sustainable strategy for treating wastewater in various industries, significantly mitigating harmful effects, including carcinogenic risks.