Pd/Uio-66/Ti Electrode for Electrocatalytic Debromination of Tetrabromobisphenol a

Abstract

Metal organic frameworks (MOFs) have engendered great interest due to their high surface areas, tunable porous size, and functionalities. They are explored in a wide range of applications including absorption, gas storage or separation, catalysis, biomedicine and drug delivery. Presently, a large number of reports appraise the application of MOFs in the field of electrochemistry, from rechargeable batteries, supercapacitors to fuel cells. Among these various metal organic frameworks, UiO-66 as a type of highly stable zirconium-based MOF linking by 1,4-benzenedicarboxylate (BDC), has been extensively studied. It is reported that UiO-66 demonstrates high structural stability in water medium, thus, it shall be a feasible strategy to incorporate UiO-66 with other functional materials for the applications in aqueous medium, water treatment and water splitting for instance. Herein, palladium nanoparticles supported UiO-66 was fabricated on Ti plate electrode (Pd/UiO-66/Ti) in this study. White UiO-66, as a bridging layer with controlled size and thickness, was first deposited on Ti plate via an electrochemical film deposition method. UiO-66/Ti plates of different thickness were acquired by changing the ratio of electrochemical deposition solution. Pd/UiO-66/Ti was further made by dipping Pd2+ solution onto the UiO-66 surface and then reduced by impregnating in 0.1 % NaBH4 solution for two hours. The obtained dark Pd/UiO-66/Ti electrode was characterized by X-ray diffraction (XRD). And the electrochemical properties of the Pd/UiO-66/Ti cathode electrode were investigated through cyclic voltammetry (CV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). The results revealed that UiO-66 films with different thickness were successfully deposited on the Ti cathodes (UiO-66/Ti), Pd particles well dispersing on the surface of the UiO-66/Ti. The electro-catalytic performance was evaluated by electrocatalytic debromination of 5 mg/L tetrabromobisphenol A (TBBPA) in a 200 mL vessel, containing Pd/UiO-66/Ti as cathode, graphite as anode at a current of 6.67 mA/cm2. It was found that degradation rate of TBBPA was 80% within 60 min by Pd/ UiO-66/Ti cathode electrode. The excellent electro-catalytic performance could be ascribed to the adsorption of TBBPA on UiO-66 and the reaction with hydrogen at the palladium/UiO-66 interface. The results indicated that Pd/UiO-66/Ti should be a promising cathode for the application on electrochemical.