Photocatalytic degradation of bisphenol A by oxygen-rich and highly visible-light responsive Bi₁₂O₁₇Cl₂ nanobelts

Visible light responsive photocatalysts can directly harvest energy from solar light, offering a desirable way to resolve environmental pollution problems through utilizing solar energy. Bismuth oxychloride (BiOCl) with a band gap of about 3.4 eV is widely recognized as an effective photocatalyst for the degradation of organic dye molecules under visible light irradiation, but such a photocatalytic degradation has to be assisted by dye-sensitization. Thus, preparation of BiOCl photocatalyst to achieve visible light response without dye-sensitization is greatly desired, as this would greatly expand their practical applications for the degradation of non-dye pollutants. In this work, oxygen-rich Bi₁₂O₁₇Cl₂ nanobelts with a band gap of 2.07 eV were synthesized by using a solvothermal route, and their photocatalytic performance was evaluated through photodegrading a colorless contaminant bisphenol A (BPA) in an aqueous solution. In comparison with BiOCl, which is not sensitive to visible light, the oxygen-rich Bi₁₂O₁₇Cl₂ nanobelts exhibited a drastically enhanced visible-light photoreactivity and were also superior to the well-known photocatalyst TiO₂ (P25). The greatly enhanced photocatalytic performance of the Bi₁₂O₁₇Cl₂ nanobelts was attributed to their efficient visible light absorption. Our findings might be helpful to explore visible light bismuth-based photocatalysts for pollutant degradation and water treatment.