Degradation of catechol on BiOCl: charge transfer complex formation and photoactivity

BiOCl photocatalysts were successfully synthesized using Bi(NO3)(3.)5H(2)O and KCl as raw materials. The physical properties and optical absorption performances of as-prepared samples were characterized through XRD, SEM, TEM, XPS and DRS. Contrary to common expectations, catechol could be degraded with visible light on as-synthesized BiOCl. The observed visible-light induced activity could be due to the formation of charge transfer complex, confirmed by DRS, FTIR, Raman, and XPS. About 65.0 % of catechol was degraded after 120 min light irradiation, and the rate constant, k, is 9.04x10(-3) min(-1). The addition of L-ascorbic acid inhibited the degradation of catechol, indicating center dot O2- being the main active species in catechol redox reaction. Finally, the degradation mechanism of catechol under visible light irradiation with BiOCl was proposed.