Synthesis of AgCl/BiOCl Composite Photocatalyst and its photocatalytic activity under visible-light irradiation

A series of BiOCl photocatalysts with different AgCl contents have been synthesized by a simple hydrolysis method at room temperature using BiCl3 and Bi(NO3)(3)center dot 5H(2)O as the main raw materials. The resulting products were characterized with X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and UV-vis diffuse reflectance spectra (DRS). The photocatalytic activities of these AgCl/BiOCl composites were evaluated by the degradation of rhodamine B (RhB) under UV and visible light. The results revealed that the BiOCl/AgCl with an initial 100:1 mole ratio of Bi to Ag have the highest photocatalytic activity. RhB (20 mg/L) was decolorized by 98.81% in 15 min under sun light, in contrast to 95.89% and 11.63% in 30 min under halogen lamp and UV light, respectively. The catalysts did not show any significant loss of activity after 19 recycles for the photodegradation of RhB, suggesting the photocatalyst is essential stable. Kinetic studies showed that the RhB photocatalytic degradation followed pseudo-first order kinetics reaction and fit the Langmuir-Hinshelwood kinetic equation. The rate controlling step was absorption reaction.