Synthesis of surface sulfated BiWO with enhanced photocatalytic performance

• Published in: Journal of environmental sciences (China) 2012-01, Vol.24 (12), p.2180-2190
• Main Authors: Ju, Yongming, Hong, Jianming, Zhang, Xiuyu, Xu, Zhencheng, Wei, Dongyang, Sang, Yanhong, Fang, Xiaohang, Fang, Jiande, Wang, Zhenxing
• Format: Article
• Language: English
• Subjects: Bismuth - chemistry; Catalysis; catalysts; Environmental Pollutants - chemistry; Environmental Pollutants - radiation effects; free radical scavengers; irradiation; lamps; Malachite Green; microwave; photocatalysis; photocatalytic; Photolysis; reactive oxygen species; Rosaniline Dyes - chemistry; Rosaniline Dyes - radiation effects; salicylic acid; sulfated BiWO; Sulfuric Acid Esters - chemical synthesis; Ultraviolet Rays; UV-Vis; visible light; 催化剂表面; 光催化性能; 可见光响应; 合成; 硫酸根; 自由基清除剂; 表面增强
• ISSN: 1001-0742; 1878-7320
• DOI: 10.1016/S1001-0742(11)61061-9

Sulfated BiWO （SBiWO） was synthesized by an impregnation method to enhance the visible-light-driven photoactivities of BiWO （BiWO）. The characterization results verified that sulfate anion mainly anchored on the catalyst surface greatly extended the visible- light-responsive range without destroying the crystal lattice. Moreover, the SBiWO-based photoactivities were evaluated with the removal of Malachite Green （MG） under UV-Vis irradiation emitted from two microwave-powered electrodeless discharge lamps （MPEDL_2） and under visible light （L 〉 420 nm）. The results demonstrated that the kinetic constant was increased 2.25 times, varying from 0.1478 （BiWO） to 0.3328 rain-1 （SBiWO- 1 ）. Similar results were also obtained for the visible light-driven reaction. Furthermore, radical scavengers such as t-butanol restricted the visible-light induced degradation of MG over BiWO and SBiWO-1. This indicated that the sulfating process increased the generation of reactive oxygen species, which was further verified by molecular probe with salicylic acid. Thus, more blue-shifting at k = 618 nm was observed over SBiWO. On the basis of the above results, the photocatalytic mechanism over the sulfated catalyst was also discussed.