Morphology-controlled self-assembly of hollow spherical heterostructured TiO2@BiOBr promotes visible-light degradation of antibiotic pollutants

Although BiOBr exhibits a good photodegradation activity for organic pollutants due to its special layered structure, low visible-light utilization and insufficiently exposed active sites limit its photocatalytic efficiency. To address these challenges, we construct TiO 2 @BiOBr (HTBB) photocatalyst by coupling hollow spherical structure and p-n heterojunction. The strong built-in electric field can boost efficient charge separation, while hollow spherical structure not only can provide abundant accessible active sites due to its unique two-sided available interfaces, but also can promote light absorption through multiple reflection mechanism. As a result, the degradation rate of levofloxacin (LVFX) over HTBB photocatalyst is as high as 96.25 % under visible light within 1 h and still maintains a high level (>90 %) after five successive cycles. Meanwhile, the photocatalytic performance of HTBB shows excellent harsh environment tolerance. Therefore, this work provides a new insight for constructing BiOBr-based hollow spherical photocatalysts for the treatment of antibiotic wastewater.