Abstract

Photocatalyst in the supported form is more meaningful in large scale wastewater treatment than using powder material. HZSM-5 zeolite was used to support boron-doped anatase TiO₂ in a sol–gel route in this work. The supported B-TiO₂(20%)/HZSM-5 composite photocatalyst has strong activity on azophloxine degradation. The crystallite size of anatase TiO₂ slightly increased from 6.1 to 8.4 nm when calcination temperature rose from 350 to 450 °C. The bandgap energies were around 3.3 eV for the composites calcined between 350 and 600 °C. The adsorption–desorption isotherm of the composites was the type IV isotherm for mesoporous material. The porous structure in the supported B-TiO₂ layer was responsible for the variations of both BET surface area and pore volume in the composite. The maximum photocatalytic activity was obtained on the sample calcined at 450 °C. After 30 min of irradiation, 61.8% of the initial azophloxine molecules were degraded on the material. The first order reaction rate constant was 0.06168 min⁻¹. Photocatalytic degradation efficiency was enhanced with increasing B-TiO₂ concentration when the B-TiO₂ dosage was below 400 mg/L.

中文翻译：

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溶胶-凝胶法合成B-TiO 2（20％）/ HZSM-5复合光催化剂用于降解甲氧嗪

摘要

负载形式的光催化剂在大规模废水处理中比使用粉末材料更有意义。在这项工作中，HZSM-5沸石被用于以溶胶-凝胶途径负载硼掺杂的锐钛矿型TiO ₂。负载的B-TiO ₂（20％）/ HZSM-5复合光催化剂对氮氧杂环丁烷的降解具有很强的活性。当煅烧温度从350℃升高到450℃时，锐钛矿型TiO ₂的微晶尺寸从6.1nm略微增加到8.4nm。对于在350至600°C之间煅烧的复合材料，带隙能约为3.3 eV。复合材料的吸附-解吸等温线是介孔材料的IV型等温线。负载型B-TiO _2中的多孔结构层是造成复合材料中BET表面积和孔体积的变化的原因。在450°C下煅烧的样品具有最大的光催化活性。辐照30分钟后，初始材料中有61.8％的初始氮氧嗪分子被降解。一级反应速率常数为0.06168min ^-1。当B-TiO ₂用量低于400 mg / L时，随着B-TiO ₂浓度的增加，光催化降解效率提高。