Cu-HAB/GO composite with superior active surface area/sites and conductivity properties for the electrocatalytic degradation of tetracycline hydrochloride

Abstract

Conventional metal–organic frameworks (MOFs) used for electrocatalytic applications have the drawbacks of poor conductivity and instability. Herein, a Cu–1,2,3,4,5,6-benzenehexamine (Cu-HAB)/graphene oxide (GO) composite was prepared for the electrocatalytic degradation of tetracycline hydrochloride (TCH). Our characterization results show that Cu-HAB/GO has more active sites (ID/IG = 1.0030), larger surface area (SBET = 395.3441 m2/g), and faster electron transport (Rct = 20.69) than Cu-HAB. Simultaneously, the improvement in the number of active sites, surface area and electron transport leads to a superior TCH electrocatalytic degradation efficiency. The reaction rate constant (0.70575 min−1) of the composite was higher with a 51.81% improvement observed when compared to Cu-HAB under the optimum conditions of 1 g/L NaCl, 20 mA, and 20 °C. In addition, 100% of the degradation efficiency was maintained after five cycles. A detailed study of the mechanism revealed that 1O2 and active chlorine were the critical active species for the degradation of TCH via quenching and electron paramagnetic resonance (EPR) studies. The possible TCH degradation pathway has been proposed. This study provides a novel and feasible method for the preparation of MOF-based electrocatalysts to expand their application to environmental fields.