Enhancing photocathodic protection with Ti3C2-Decorated BiVO4 microspheres

In order to solve the problem of low carrier separation efficiency and large electron-transmission loss in transfer process of BiVO4; therefore, this study considered titanium carbide (Ti3C2) as a photoelectron-transfer agent for use in photocathodic protection (PCP) applications. Frist, SEM characterization proved that the typical accordion structure of Ti3C2 could be controlled by adjusting the etching time (36 h) and temperature (50 ℃). As-prepared Ti3C2 could reduced the volume resistivity of epoxy resin by four orders of magnitude and has excellent hydrophilicity. Second, different mass ratios of Ti3C2 to BiVO4 were also tested. When the ratio of BiVO4 to Ti3C2 was 1:2, the mixture self-assembled into BiVO4/Ti3C2 microspheres owing to the electrostatic adsorption of functional groups on the Ti3C2 surface. Third, the PEC test demonstrated that 304SS coupled with BiVO4/Ti3C2 (B:T = 1:2) photoanode showed an enhanced photocurrent density (154 μA•cm−2) and maximum potential drop (799 mV), which were equivalent to 3.5 times and 2.18 times that of the bare BiVO4, respectively. Mechanism study illustrated that enhanced performance of the BiVO4/Ti3C2 photoanode was attributed to Ti3C2 increased the hydrophilicity and conductivity, promoting the differentiation of the photocurrent in composite microspheres, and the interconnection structure helped maintain long-term stability.