TiO2 Microflowers Assembled by 6-nm Single-Crystal Stranded Wires with Improved Photoelectrochemical Performances

As the diffusion length of charge carriers in TiO2 is around 10 nm, it would be an efficient way to increase the photocatalytic properties by controlling the size within 10 nm. Herein, TiO2 microflowers assembled by 6-nm single-crystal stranded wires grown on Ti foam (TiO2-SWs/TF) were synthesized which facilated electron transfer rate with a photocurrent of 0.33 mA cm−2 compared to that of the P25/TF (0.06 mA cm−2). A photoelectrochemical (PEC) system combining degradation of bisphenol A and H2 production was constructed based on the as-obtained TiO2-SWs/TF as photoanode and Pt wire as cathode. This PEC system exhibited excellent ability for simultaneous bisphenol A degradation and H2 production, giving a 94% bisphenol A degradation efficiency within 60 min at 1.2 vs (Ag/AgCl) V with power consumption of only 0.02 kWh m−3. The excellent PEC degradation of bisphenol A by the TiO2-SWs/TF could mainly be ascribed to the fast electron transfer via the 6-nm ultrathin wires and synergetic effect of photocatalysis and electrochemical process. Two pathways for PEC degradation of bisphenol A were proposed based on the intermediates identified by Ultra Performance liquid chromatography-quadruple-time of flight-mass spectrometry (UPLC-Q-TOF-MS).