Ultrasound-assisted room-temperature in situ precipitation synthesis of BC doped Bi4O5Br2 for enhanced photocatalytic activity in pollutants degradation under visible light

A novel photocatalyst based on the integration of biochar (BC) with Bi4O5Br2 using an ultrasound-assisted room-temperature in situ precipitation method was facilely prepared. The morphological, optical, structural and photoelectrochemical characteristics of the composites were studied via various techniques. The photocatalytic result confirmed that the BC/Bi4O5Br2 photocatalyst with 1.5 wt% of Bi4O5Br2 has achieved 99.98% removal efficiency in removing Rhodamine B (RhB) within 25 min, and 93.53% removal efficiency in removing tetracycline hydrochloride (TCH) within 90 min, respectively. This boosted photoability in the composite was attributed to the synergistic interactions between BC and Bi4O5Br2, more effective charge separation, and enhancing the absorption of visible light. Due to this optimization and more activity sites generated in the photocatalyst surface, an improvement of the •O2- generation were displayed by the trapping experiments. Moreover, the composite showed acceptable stability. This study supplies new information to the construction of visible-light-induced photocatalysts based on Bi4O5Br2 under room-temperature for efficient degradation of organic pollutants.