Oxygen vacancy assisted the enhancement of photocatalytic activities in ultrathin Bi7Fe2Ti2O17Cl nanosheets

High photo -generated carrier recombination rate and weak spectral response are important constrained factors for the enhancement of photocatalytic activities. In this contribution, ultrathin Bi7Fe2Ti2O17Cl nanosheets with Sille ' n-Aurivillius structure were fabricated from ultrasonic assisted exfoliation. The relevant photocatalytic activities were evaluated by the degradation of rhodamine B (RhB) pollutant solutions and the reduction of CO2 under the visible light irradiation. The formation of oxygen vacancies (OVs) can build the new donor level of OVs and reduce the band gap in ultrathin Bi7Fe2Ti2O17Cl nanosheets, which can enhance the light absorption of nanosheets. Simultaneously, this created energy level also can expedite the separation and migration efficiencies of photo -generated charges, boosting the reaction rate. Eventually, the photocatalytic performance of ultrathin Bi7Fe2Ti2O17Cl nanosheets demonstrates the superior photocatalytic activities, with CH3OH yield from CO2 and RhB degradation efficiencies under the visible light irradiation, are 2.16 and 3.87 times higher than those of the raw Bi7Fe2Ti2O17Cl material fabricated from the molten salt synthesis method. This work aims at providing a simple and easy route for the exfoliation of Sille ' n-Aurivillius oxyhalides to boost photocatalytic performances.