Synthesis and photocatalytic degradation ability evaluation for rhodamine B of ZnO@SiO2 composite with flower-like structure

• Published in: Water science and technology 2019-11, Vol.80 (10), p.1986-1995
• Main Authors: Shen, Xiaoyi, Shi, Youjiang, Shao, Hongmei, Liu, Yan, Zhai, Yuchun
• Format: Article
• Language: English
• Subjects: Access; Catalytic activity; Degradation; Flowers; Membrane separation; Morphology; Photocatalysis; Photodegradation; Raw materials; Rhodamine; Scanning electron microscopy; Silica; Silicon dioxide; Synthesis; Zinc oxide; Zinc oxides
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2020.020

ZnO@SiO2 composite with flower-like structure was successfully prepared with molar ratio of ZnO/SiO2 = 1:1 based on the optimized synthesizing parameters of spherical SiO2 and flower-like ZnO. SiO2 particles were coated on the flower-like ZnO to form a homogeneous film through the multidimensional polycondensation of Si(OH)4. The photocatalytic degradation ability of ZnO@SiO2 composite for rhodamine B (RhB) obtained at different ZnO/SiO2 molar ratio and the comparison to that of flower-like ZnO showed that ZnO@SiO2 composite with ZnO/SiO2 molar ratio of 1:1 displayed a relatively good photocatalytic degradation ability to degrade RhB, but it was weaker than that of flower-like ZnO. Twenty millilitres of RhB solution at a concentration of 15 mg·L−1 could be completely degraded by 300 mg flower-like ZnO powder within 3 h, while the degrading efficiency was only 82.5% by 300 mg ZnO@SiO2 composite. But ZnO@SiO2 composite showed a better photocatalytic activity than flower-like ZnO at a lower pH value of 4.5.