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

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.

A series of ZnS photocatalysts were prepared by a solvothermal method with ethylene glyclo as the reaction medium and zninc acetate （Zn （ CHACOO ） 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 Nz physical adsorption （BET）, scanning electron microscopy （SEM）,X-ray diffraction （XRD）,UV-vis diffuse reflectance spectra （UV-vis DRS）, and photolumineseence spectroscopy （PL）. The photocatalytic activity of the prepared samples was evaluated by photocatalytic degradation of different dyes under UV light （A=254 nm） irradiation. The experimental results show that these photoeatalysts prepared under solvothermal condition have good erystallinity 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 1I, methyl orange, methylene blue, and rhodamine B are 91.49 %, 93.04 %, 64.63 % and 51.79 %, respectively. This high photoeatalytie activity is mainly attributed to the good crystallnity, big surface area, and less crystal defects of the ZnS prepared under the optimal condition.