Preparation of macro-porous 3D boron-doped diamond electrode with surface micro structure regulation to enhance electrochemical degradation performance

Abstract Boron-doped diamond (BDD) is commonly considered as an excellent electrode material toward electrochemical oxidation, and its specific surface area is an important factor in determining its electrocatalytic performance. In this work, we have prepared three-dimensional (3D) BDD film material on the foamed Cu/W surface, denoted by Cu/W/BDD. A cone-shaped structure formed during the thermal treatment due to the phenomenon of BDD thermal weight loss, and thereafter the intermingled macro-micro structure of BDD was obtained. This intermingled 3D-BDD structure (3D-BDD1) has a high electrochemically active surface area, which is 7.9 times higher than that of 2D planar BDD structure (2D-BDD). The tetracycline hydrochloride (TCH) was chosen as the research benchmark to compare the performance difference of 3D intermingled structure and 2D planar structure. The TCH removal and the total organic carbon (TOC) removal by 3D-BDD1 is 1.51 times and 5.31 times than those by 2D-BDD, respectively. The electric energy of 2D-BDD and 3D-BDD1 needed to reduce the TOC concentration by 1 order of magnitude is 28.76 and 3.43 kWh m−3 order-1. The 2D-BDD consumed 7.95 times more energy per unit of TOC removal than the 3D-BDD1. In combination with fluid dynamics simulation, the fluid turbulence form of 3D structure and its disturbance to fluid flow are considered as the major reason responsible for the enhancement of degradation performance.