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).