One-step preparation of reduced graphene oxide aerogel loaded with mesoporous copper ferrite nanocubes: A highly efficient catalyst in microwave-assisted Fenton reaction

Heterogeneous Fenton reaction is an attractive method for degradation of organic pollutants due to its high efficiency and non-selectivity and it also causes no secondary pollution. However, low degradation rate and poor recyclability of the catalysts limit its applications for water purification. To overcome this, herein, copper ferrite/reduced graphene oxide (CF/rGO) aerogel was prepared by a one-step hydrothermal method, as a highly efficient catalyst for the microwave-assisted Fenton reaction (MAFR). Under optimal conditions (500 W of microwave power, 600 μL of H2O2, 15 mg of catalyst, and 30 mg/L of RhB), the degradation efficiency of CF/rGO aerogel at 1.0 min (95.7%) was higher than that of reference samples at 3.0 min. Thermodynamical study showed the activation energy, enthalpy change, entropy change, and Gibbs free energy change were 0.73 kJ/mol, -49.5 kJ/mol, -0.135 kJ/mol·K, and -6.8 kJ/mol, respectively, indicating that MAFR was an endothermic and non-spontaneous process.Radical trapping experiments showed that OH, O2-, and h+ played a combined role in RhB degradation. Besides high catalytic activity, CF/rGO aerogel also displayed good reusability, showing removal efficiency of 87.4% after 5 cycles. The high efficiency, good reusability, and simple process make CF/rGO aerogel a promising catalyst for wastewater treatment.