Hydrothermal Synthesis of Flower-Like CuO/ZnO/SiNWs Photocatalyst for Degradation of R6G under Visible Light Irradiation

Abstract:

Flower-like CuO/ZnO/SiNWs nanostructures were successfully synthesized on SiNWs substrates using a simple hydrothermal method. The characteristics of the CuO/ZnO/SiNWs nanostructures were investigated through scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV–vis spectrophotometer. SEM images revealed shape transitions when the precursor mass ratic increased from 50:50 to 5:95. The strong intensity and narrow width of XRD peaks indicate that CuO/ZnO nanostructures with high molarities have good crystallinity. The UV–vis spectro-photometer indicate that ultraviolet emissions shift slightly toward lower wavelengths with incr-easing precursor solution molarity and that the intensity increases with improvement in CuO/ZnO/SiNWs crystallization.The mechanism of CuO/ZnO/SiNWs for improvement in photocatalytic activity was also discussed.

• Periodical: Key Engineering Materials (Volume 727)
• Pages: 847-852
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.727.847
• Online since: January 2017
• Authors: Qi Feng, Shao Yuan Li*, Wen Hui Ma, Xiao He, Yu Xin Zou
• Keywords: Flower-Like CuO/ZnO/SiNWs, Photocatalytic Activity, SiNWs, Visible Irradiation

References

[29] Thus, it is considered that the loaded CuO on ZnO/SiNWs can promote the transfer of electrons in ZnO/SiNWs conduction band to outer oxygen, in the meanwhile it degrades the R6G. In other words, transfer of electrons from CuO to ZnO/SiNWs is possible due to work function of CuO being similar to that of ZnO.

DOI: 10.4028/www.scientific.net/kem.727.847

[30] To better enhance the decomposition rate, experiments were performed with external electron acceptors, such as H2O2 , and the observed rate constants are in the following H2O2 (k = 3. 9×10−2 min−1) (experimental conditions are as follows: Dye [1×10−5 M]; and H2O2 [1×10−5 M] (Fig. 4(c). The reason for such enhanced rate constant is due to the generation of enhanced number of surface active radicals by reaction between electron acceptors and CuO/ZnO/SiNWs. Conclusion Doping of copper on ZnO surface has been successfully conducted through wet impregnation method for the improvement of photocatalytic degradation of R6G. As prepared CuO-ZnO-SiNWs exhibits notably high photocatalytic activity in decomposing R6G under visible light irradiation. This may be due to the role of loaded metal in trapping and subsequent transfer of photoexcited electrons. Also through various characterization studies, it is identified that Cu in the as prepared nanocomposites belongs to CuO phase only. Acknowledgements Financial support of this work from the National Natural Science Foundation of China (Grant No. 51504117), Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20135314110001), Research Project Fund of Yunnan Province Collaborative Innovation Center of Complex Nonferrous Metal Resources Comprehensive Utilization (Grant No. 2014XTZS009) and Open Project of State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization (Grant No. CNMRCUKF1404). Refernces.

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