Facile fabrication of heterogeneous TiO2/BiOCl composite with superior visible-light-driven performance towards Cr(VI) and tetracycline

Abstract

Heavy metals and antibiotics are known for their difficulty of removal and enormous harmful intermediates released during degradation as well as the great threat to the health of human beings, which arouses urgent demand for highly efficient photocatalysts as solution. Thus, in this work, TiO2/BiOCl heterogeneous composite was synthesized via a facile and low-cost hydrolysis-precipitation method at room temperature without organic reagent. The characteristic results indicate anatase TiO2 nanoparticles with smaller grain size (around 15 nm) were uniformly dispersed on the surface of BiOCl nanosheets to form the heterogeneous structure. The hybrid catalyst exhibits higher photocatalytic performance for both Cr(VI) and tetracycline, and the synergistic degradation effect is demonstrated in the co-existent system. The superior photoactivity is mainly attributed to the excellent visible light capture capability and effective separation of photogenerated electron-holes pairs. Moreover, the main active radicals for Cr(VI) are photo-induced electrons (e−), and that for tetracycline are superoxide radical (•O2−) and holes (h+). Furthermore, the effect of mass ratio of TiO2 and BiOCl on the photocatalytic performance was discussed and a speculated degradation mechanism was also proposed. In summary, this work would provide significant meaningful guidance for the development of Ti-based composites in the field of wastewater treatment.