PbO2 modified BDD electrode by dicationic ionic liquids assisted electrodeposition for efficient electrocatalytic degradation of pesticide wastewater

Abstract

Pesticide wastewater is difficult to treat, and it is necessary to develop a new anode material electrochemical oxidation to efficiently degrade pesticide wastewater. DIL-PbO2-Ti/BDD electrodes with better electrocatalytic oxidation performance were obtained by using dicationic ionic liquid (DIL) for assisted electrodeposition of PbO2 modified boron-doped diamond (BDD) electrodes. At a current density of 100 mA cm-2 and a temperature of 25 °C, the DIL-PbO2-Ti/BDD electrode was used as anode and titanium plate as cathode. The electrochemical window and oxygen evolution potential (OEP) of the DIL-PbO2-Ti/BDD electrode obtained by CV testing at a scan rate of 50 mV s-1 in 1 M H2SO4 were 4.12 and 3.29 V, respectively. Under the conditions of current density of 100 mA cm-2, 25 °C, pH 12, salt content of 8%, chemical oxygen demand (COD) of 24,280.98 mg L-1, and total nitrogen (TN) content of 5268 mg L-1, after electrification for 12 h, the removal efficiency of COD and TN reached 64.88 and 67.77%, respectively, indicating that the DIL-PbO2-Ti/BDD electrode has excellent electrocatalytic performance. In order to further understand the mechanism of electrochemical degradation of pesticide wastewater, HPLC-MS was used to detect the intermediates in the degradation process, and the possible degradation pathways were proposed in turn.