Generation of singlet oxygen over Bi(V)/Bi(III) composite and its use for oxidative degradation of organic pollutants

An efficient singlet oxygen generation system was first developed by using Bi(V)/Bi(III) composites for degrading organic pollutants. The composites were prepared by hydrolyzing NaBiO3 in HCl solutions. As monitored by various techniques, it was found that the morphology and composition of the composites were able to be tuned by changing the molar ratio of HCI to NaBiO3 in the preparation process, which was optimized at 2.0. Due to the efficient generation of singlet oxygen, the use of the composite (0.75 g L-1) resulted in almost complete degradation of bisphenol A (0.2 mmol L-1) in 20 min, with a pseudo-first-order kinetic constant of 0.14 min(-1). The dominant reactive species in the degradation system were confirmed to be singlet oxygen, which was generated from the release of the lattice oxygen in the composite. The good performances of the concerned singlet oxygen generation system are general for degrading different organic pollutants. (C) 2014 Elsevier B.V. All rights reserved.