2.3.1. Synthesis of the ZnCo2O4
A microwave-assisted synthesis method was used to synthesize ZnCo2O4 particles. The specific preparation process is as follows: 7.5 mmol of Zn(NO3)2·6H2O, 15 mmol of Co(NO3)3.6H2O, 60 mmol of CO(NH2)2 and 12 mmol of NH4F were successively added to 100 ml of deionized water, using a magnetic stirrer to stir for 30 minutes and ultrasound for 30 minutes to completely dissolve the medicine and form a light pink solution. Then transfer the mixed solution to a 300 ml polytetrafluoroethylene reaction tank, assemble the reaction instrument, and place it in the microwave device, heating at a rate of 8 °C/min and microwave reaction at 130 °C for 30 min. When the reaction is complete, the product temperature is brought to room temperature, and then the drug is collected by centrifugation, filtration, and repeat washing with deionized water, dried in the oven at 80 °C for 10 hours, and finally calcined in the tubular muffle furnace at 350 °C for 2 hours at a heating rate of 1 °C/min to obtain the product, which is collected for standby.