Abstract
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•Fe was incorporated into the structure of TiO2 via one-step thermal process.•Fe-TiO2/rGO exhibited excellent activity for BPA and its analogues degradation.•The visible light absorption of Fe-TiO2/rGO was extended by Fe ions and rGO.•The photocatalysis was promoted due to the presence of Ti3+.•Superoxide radicals play the prominent role during the photodegradation of BPA.
For extending the light response to visible spectrum, an approach to efficient photocatalysts in sustainable energy technology has been a hot research topic. In this work, Fe doped TiO2/rGO (Fe-TiO2/rGO) was synthesized via one-step hydrothermal deposition method. The presence of Fe-Ti bond and Ti3+ in the photocatalyst was confirmed by XPS, EXAFS and Raman analyses. The batch experiments showed that as-synthesized Fe-TiO2/rGO nanocomposites exhibited high photocatalytic performance for bisphenol A (BPA) and its analogues degradation under visible light irradiation (λ ≥ 420 nm). Moreover, Fe-TiO2/rGO presented high photocatalytic activity at a high BPA concentration of 95 ppm as well as a wide pH value of 4.5–8.5. Additionally, the extended visible light absorption range Fe-TiO2/rGO was demonstrated by low temperature electron spin resonance, UV–vis diffuse reflectance spectra, the transient photocurrent density and electrochemical impedance spectroscopies measurements. The radical quenching and ESR active species trapping experiments implied the main role of superoxide radicals on the high efficient photodegradation of BPA. These findings are crucial for designing TiO2-based photocatalysts with high performance for degradation of persistent organic pollutants in wastewater treatment.