BiOBr nanoflakes with engineered thickness for boosted photodegradation of RhB under visible light irradiation

Direct discharge of massive textile dyes into natural water urges us to exploit an efficient technique and further alleviate the pollution level. Herein, a series of BiOBr nanoflakes with different thicknesses were successfully fabricated by a simple adjustment of bromine sources, and the photodegradation of rhodamine B (RhB) was further explored under visible light irradiation. The results indicated that the BiOBr photocatalyst synthesized with CTAB as the bromine source (BOB-CTAB) delivered the top-flight photocatalytic performance, and the degradation efficiency of RhB achieved 98.7% within 20 min. The improved photoactivity was attributed to the ultrathin nanoflakes structure, reduced band gap, enhanced transfer rate of light-induced electron-hole pairs. The cycling experiment suggested that the exceptional BOB-CTAB photocatalyst can still remove more than 88% of RhB after 5 cycles. In addition, the boosted photodegradation mechanism was systematically elaborated. This work provides a new strategy to accelerate the photodegradation efficiency for water purification by engineering the thickness of BiOBr nanoflakes.