Facet exposure-dependent photoelectrocatalytic oxidation kinetics of bisphenol A on nanocrystalline {001} TiO2/carbon aerogel electrode

An anatase TiO 2 with {001} facet exhibits high oxidation activity towards the degradation of wastewater. The impact of {001} facet exposure degree on the degradation oxidation kinetics and mechanism is still unclear and urgently needs to be discussed. The photoelectrocatalytic (PEC) degradation of bisphenol A (BPA) in wastewater using facet-controlled nanocrystalline {001} TiO 2 /carbon aerogel (CA) photoelectrodes was then investigated in this study. Nano-sized anatase {001} TiO 2 crystals with different {001} facet exposure degrees of high (90%), medium (48%) and low (15%) were constructed on a CA substrate via electrophoretic deposition. A positive correlation was found between the {001} facet exposure and the photocurrent density, electron carrier concentration and the total amount of OH. Nearly 100% BPA removal efficiency was shown on the 90%-{001}TiO 2 /CA in 6   h. The rate constant ( k ) value was 0.454   h −1 and the TOC rate was 83%. They are 1.8 and 1.8 times greater than those obtained on the 48%-{001}TiO 2 /CA, as well as 3.5 and 2.4 times greater than those on the 15%-{001}TiO 2 /CA, respectively. The greatly promoted PEC oxidation activity of 90%-{001}TiO 2 /CA is due to its more rapidly accumulated intermediates products than other two photoelectrodes, which then completely mineralize into CO 2 and H 2 O. This is mainly because of the highest oxidation sites existed on the 90%-{001}TiO 2 surface and the efficient separation of electron-hole pairs between the {001} TiO 2 and CA under the electric fields.