溶剂热制备球状ZnS 纳米光催化剂及其光催化性能

Solvothermal preparation spherical ZnS nano-photocatalyst and its photocatalytic activity

  • 摘要: 以乙二醇为反应介质,醋酸锌(Zn(CH3COO)2·2H2O)和硫脲((NH2)2CS)为原料,采用溶剂热法制备了系列ZnS 光催化剂. 考察了不同反应温度、时间对ZnS 的结晶度、比表面积、光吸收性能及其光催化性能的影响. 利用N2物理吸附(BET)、扫描电镜(SEM)、X 射线衍射(XRD)、紫外可见漫反射光谱(UV-vis DRS)和光致发光谱(PL)对样品进行了表征.以紫外灯(λ=254 nm)为光源,对所得样品进行了光催化降解不同染料的活性测试.研究结果表明,该系列催化剂均具有较好的结晶性能,具有球状形貌.但在140 ℃下处理16 h 的ZnS 样品表现了最高的光催化活性. 光照5 h 后, 染料酸性橙Ⅱ、甲基橙、亚甲基蓝、罗丹明B 的降解率分别达到91.49 %、93.04 %、64.63 %和51.79 %.这主要归于该条件下制备的ZnS 具有比较好的结晶性能、大比表面积和较少的晶格缺陷.

     

    Abstract: A series of ZnS photocatalysts were prepared by a solvothermal method with ethylene glyclo as the reaction medium and zninc acetate (Zn (CH3COO)2·2H2O)and thiourea ( (NH2)2CS)as the precursors. The effects of reaction temperature and time on the crystallnity , surface area, optic adsorption and photocatalytic performance of the ZnS were investigated. The obtained ZnS samlpes were characterized by N2 physical adsorption (BET), scanning electron microscopy (SEM),X-ray diffraction (XRD),UV-vis diffuse reflectance spectra (UV-vis DRS), and photoluminescence spectroscopy (PL). The photocatalytic activity of the prepared samples was evaluated by photocatalytic degradation of different dyes under UV light (λ=254 nm) irradiation. The experimental results show that these photocatalysts prepared under solvothermal condition have good crystallinity and spherical morphology. ZnS photocatalyst prepared at 140 ℃ for 16 h shows the highest photocatalytic activity in decomposition of the dyes. After 5 hours ’ light irradiation, the degradation rates of the dyes of acid orange II, methyl orange, methylene blue, and rhodamine B are 91.49 %, 93.04 %, 64.63 % and 51.79 %, respectively. This high photocatalytic activity is mainly attributed to the good crystallnity , big surface area, and less crystal defects of the ZnS prepared under the optimal condition.

     

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