Effect of pretreatment temperature on the photocatalytic activity of microwave irradiated porous nanocrystalline ZnO
Effect of pretreatment temperature on the photocatalytic activity of microwave irradiated porous nanocrystalline ZnO
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DOI：
10.1039/c4nj01465k
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发表时间：
2015-01-01
影响因子：
3.3
通讯作者：
Al-Thabaiti, Shaeel A.
中科院分区：
文献类型：
--
作者：
Ali, Tarek T.;Narasimharao, Katabathini;Al-Thabaiti, Shaeel A.
采用微波辐射法成功合成了多孔纳米ZnO光催化剂，并在不同温度（150 ℃、200 ℃、250 ℃和300 ℃）下进行了热处理。通过使用不同的表征技术，合成样品的物理化学性质进行了测定。表征结果表明，合成的样品由ZnO和Zn（OH）（2）相组成，粒径约为50 nm。在150 ° C下对所合成的样品进行热处理，得到粒径为40 nm的纯ZnO相。结果还表明，在200 ℃下处理的ZnO样品的比表面积、孔径和带隙能达到最大值。在200 ℃下预处理的ZnO纳米粒子在短的反应时间（90 min）内表现出最高的光催化活性（99%的降解），这可以归因于几个因素的综合作用，包括低的晶粒尺寸，相对较高的表面积，孔径，孔体积和带隙能量。可重复使用性的结果表明，催化剂可以很容易地从反应混合物中分离的光催化反应后，通过过滤和重复使用至少5次没有任何损失的活性。
Porous nanocrystalline ZnO photocatalysts were successfully synthesized by microwave irradiation and then thermally treated at different temperatures (150 degrees C, 200 degrees C, 250 degrees C and 300 degrees C). The physicochemical properties of synthesized samples were determined by using different characterization techniques. The characterization results indicated that the as-synthesized sample was comprised of both ZnO and Zn(OH)(2) phases with a particle size of approximately 50 nm. Thermal treatment of the as-synthesized sample at 150 degrees C resulted in a pure ZnO phase with a particle size of 40 nm. The results also demonstrated that the surface area, pore diameter and bandgap energy reach a maximum value for the ZnO sample treated at 200 degrees C. The ZnO nanoparticles pretreated at 200 degrees C showed the highest photocatalytic activity (99% of degradation) in a short reaction time (90 min), which can be attributed to the combined effects of several factors including low crystallite size, relatively high surface area, pore diameter, pore volume and bandgap energy. Reusability results show that the catalysts can be readily separated from the reaction mixture by filtration after the photocatalytic reaction and reused at least five times without any loss of activity.