Magnetically recoverable B,F,P-TiO2/Fe3O4 nanophotocatalyst with enhanced charge separation efficiency

摘要

A magnetically recoverable B, F, P-TiO2/Fe3O4 nanophotocatalyst was prepared via a microwave-hydrothermal process and subsequent calcination after grinding B, F, P-TiO2 and Fe3O4 nanosheets in an agate mortar. The synergetic effects of B, F, P-tridoping and Fe3O4 coupling on promoting the photogenerated charge separation of TiO2 were confirmed by photoluminescence spectroscopy (PL), surface photovoltage spectra (SPS), and electrochemical impedance spectroscopy (EIS). B, F, P-TiO2/Fe3O4 exhibited typical superparamagnetic behavior and sufficient magnetic recycling property, as well as excellent photoactivity for the degradation of 4-chlorophenol (4-CP) under simulated sunlight irradiation (K-app = 1.1 x 10(-2) min(-1)), almost equal to that of P25 TiO2 (Kapp = 1.13 x 10(-2) min(-1)). center dot OH radical was confirmed to be a main activated species in the photocatalytic processes. No positive correlation between surface hydroxyl content and center dot OH radical generation amount was observed. Photogenerated charge separation efficiency superior to other factors including photoabsorption ability, phase structure, surface hydroxyl, and textural property, played a dominant role in improving the photoactivity. This work provides a promising approach to develop magnetically recoverable high-performance photocatalysts suitable to wide application for wastewater treatment.