Microwave-assisted synthesis of bismuth oxybromochloride nanoflakes for visible light photodegradation of pollutants

BiOBrxCl1-x (0 < x < 1) nanoflakes with lateral dimensions of similar to 1 mu m and thickness of < 100 nm were synthesized using bismuth nitrate pentahydrate, potassium bromide and sodium chloride by a microwave-assisted synthesis method. The X-ray diffraction (XRD) studies confirmed the formation of pure crystalline phase of BiOBrxCl1-x. The UV-visible diffuse reflectance and photoluminescence (PL) spectroscopies revealed the indirect band gap of similar to 2.82 eV for the bismuth oxybromochloride nanoflakes. Visible light-assisted photocatalytic studies showed that the degradation efficiency of the as-prepared BiOBrxCl1-x for (100 mL of 10 mg L-1) Rhoclamine B (RhB), Natural Red 4 (N-Red) dye solutions was 98.14% and for the colorless organic pentachlorophenol (PCP) solution was 91.09% over 150 min. The possible mechanisms involved in the visible light photodegradation of the pollutants by BiOBrxCl1-x photocatalyst were also discussed. (C) 2015 Elsevier B.V. All rights reserved.