Iodine-Deficient BiO1.2 I0.6 Coupling with Bi2 O3 for Degradation of Volatile Organic Compounds under Simulated Sunlight Irradiation.

Abstract

A photocatalyst with a high separation efficiency of carriers is crucial for the photocatalytic efficient decomposition of volatile organic compounds (VOCs). In this work, a new iodine-deficient BiO1.2 I0.6 /Bi2 O3 photocatalyst was developed through a solvothermal approach coupled with thermal decomposition. The 2 wt % BiO1.2 I0.6 /Bi2 O3 sample demonstrated optimal photocatalytic activity for the degradation of toluene, achieving a 55.1 % mineralization ratio under 8 h of irradiation, which was 14.9 and 2.1 times higher than those of BiO1.2 I0.6 and Bi2 O3 , respectively. Compared with BiO1.2 I0.6 and Bi2 O3 , 2 wt % BiO1.2 I0.6 /Bi2 O3 exhibited the weakest fluorescence band, highest photocurrent density, and lowest impedance; thus suggesting that Bi2 O3 compounded by 2 wt % BiO1.2 I0.6 distinctly promoted the separation efficiency of carriers. The hydroxyl radical (. OH) was the main active species, apart from holes, for the photocatalytic degradation of toluene.