Dien Nguyen Dac, Thu Ha Pham Thi, Vu Xuan Hoa, Trang Tran Thu, Thanh Giang Trinh Duc, Dung Nguyen Thi
Faculty of Occupational Safety and Health, Vietnam Trade Union University 169 Tay Son Street, Dong Da district Ha Noi city 100000 Vietnam.
Faculty of Chemistry, TNU-University of Sciences Tan Thinh ward Thai Nguyen city 24000 Vietnam.
RSC Adv. 2023 Aug 16;13(35):24505-24518. doi: 10.1039/d3ra03791f. eCollection 2023 Aug 11.
CuO/ZnO nanocomposites with different components can overcome the drawbacks of previously used photocatalysts owing to their promotion in charge separation and transportation, light absorption, and the photo-oxidation of dyes. In this study, CuO nanoplates were synthesized by the hydrothermal method, while ZnO nanoparticles were fabricated by the precipitation method. A series of CuO/ZnO nanocomposites with different ZnO-to-CuO weight ratios, namely, 2 : 8, 4 : 6, 5 : 5, 6 : 4, and 8 : 2 were obtained a mixing process. X-ray diffraction patterns confirmed the presence of hexagonal wurtzite ZnO and monoclinic CuO in the synthesized CuO/ZnO nanocomposites. Scanning electron microscopy showed the dispersion of ZnO nanoparticles on the surface of CuO nanoplates. Ultraviolet-visible absorption spectra exhibited a slight red-shift in the absorption edge of binary oxides relative to pure ZnO or CuO. All samples were employed for the photocatalytic degradation of methylene blue (MB) under visible light irradiation. The composite samples exhibited enhanced photocatalytic performance compared with pristine CuO or ZnO. This study aimed to examine the effect of the ZnO-to-CuO weight ratio on their photocatalytic performance. The results indicated that among all the synthesized nanocomposites and pristine oxides, the nanocomposite with ZnO and CuO in a proportion of 4 : 6 shows the highest photodegradation activity for the removal of MB with 93% MB photodegraded within 60 min at an initial MB concentration of 5 ppm. The photocatalytic kinetic data were described well by the pseudo-first-order model with a high correlation coefficient of 0.95. The photocatalytic mechanism of the mixed metal oxide was proposed and discussed in detail. The photodegradation characteristic of CuO/ZnO nanostructures is valuable for methylene blue degradation from aqueous solutions as well as environmental purification in various fields.
具有不同组分的CuO/ZnO纳米复合材料能够克服先前使用的光催化剂的缺点，这归因于它们在电荷分离与传输、光吸收以及染料的光氧化方面的促进作用。在本研究中，采用水热法合成了CuO纳米片，而通过沉淀法制备了ZnO纳米颗粒。通过混合过程获得了一系列具有不同ZnO与CuO重量比（即2∶8、4∶6、5∶5、6∶4和8∶2）的CuO/ZnO纳米复合材料。X射线衍射图谱证实了在合成的CuO/ZnO纳米复合材料中存在六方纤锌矿ZnO和单斜CuO。扫描电子显微镜显示ZnO纳米颗粒分散在CuO纳米片的表面。紫外可见吸收光谱表明二元氧化物的吸收边缘相对于纯ZnO或CuO有轻微的红移。所有样品都用于在可见光照射下对亚甲基蓝（MB）进行光催化降解。与原始的CuO或ZnO相比，复合样品表现出增强的光催化性能。本研究旨在考察ZnO与CuO重量比对其光催化性能的影响。结果表明，在所有合成的纳米复合材料和原始氧化物中，ZnO与CuO比例为4∶6的纳米复合材料对MB的去除表现出最高的光降解活性，在初始MB浓度为5 ppm时，60分钟内93%的MB被光降解。光催化动力学数据通过伪一级模型得到了很好的描述且相关系数高达0.95。详细提出并讨论了混合金属氧化物的光催化机理。CuO/ZnO纳米结构的光降解特性对于从水溶液中降解亚甲基蓝以及各个领域的环境净化具有重要价值。
