β-Cyclodextrin-enhanced photodegradation of bis(4-hydroxyphenyl)ethane under UV irradiation

β-Cyclodextrin (β-CD) reacts with bis(4-hydroxyphenyl)ethane (BPE) forming a 1:1 inclusion complex, the formation constant of which is 7.81 × 103 l mol−1. In the present study, the enhanced photodegradation behavior of BPE in the presence of β-CD was investigated under a 30 W UV lamp (λmax = 254 nm). As a result, the photodegradation rate constant of BPE in aqueous solution with β-CD showed a 5.37-fold increase. After 60 min UV irradiation, addition of β-CD increased the photodegradation efficiency of 10.0 mg l−1 BPE by about 54.4%, simultaneously enhancing the mineralization of BPE. The effect of β-CD concentration, the presence/absence of organic solvent and pH on the photodegradation of BPE were also studied. The predominant photodegradation products were p-hydroxybenzoic acid, m-hydroxylated BPE and o-hydroxylated BPE. The enhancement of photodegradation of BPE was mainly shown to be the result of an increase in the frontier electron density of BPE after inclusion of β-CD and the moderate inclusion depth of BPE molecules in the β-CD cavity.

The enhanced photodegradation behavior of bis(4-hydroxyphenyl)ethane (BPE) in the presence of β-CD was investigated under a 30 W UV lamp (λmax = 254 nm); the photodegradation reaction rate constant of BPE in aqueous solution with β-CD showed a 5.37-fold increase. After 60 min UV irradiation, β-CD increased the photodegradation efficiency of 10.0 mg l−1 BPE by about 54.4%. Figure optionsDownload as PowerPoint slide