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Spin coating process and photocatalytic activities of modified graphene thin film |
SUN Shiqing1, ZHENG Yanyin1,2, GU Baoshan2, GUO Dong1, QIN Sen1, FU Kai1 |
1. School of Materials Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050000, China; 2. National Engineering Laboratory for Advanced Coatings Technology of Metal Materials, China Iron and Steel Research Institute Group, Beijing 100081, China |
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Abstract Modified graphene dispersion was prepared by the modified Hummer method, and the modified graphene film was prepared on the glass substrate by spin coating method. The effects of low speed (600-800 r/min), medium speed (1 000-2 000 r/min), high speed (3 000-5 000 r/min), dropping time (10-30 s), acceleration (100-700 r/(min·s)) and pH value (4-11) on the adhesion of the thin graphene film were studied, and the optimized spin coating process parameterts were obtained. The modified graphene and its film were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy, Raman spectroscopy and laser confocal spectroscopy. The effect of the modified graphene film on the degradation of methylene blue in visible light was emphasically studied, and the photocatalytic principle of visible light was preliminarily revealed. The results show that the modified graphene film with the optimum adhesion can be obtained by rotating the modified graphene dispersion whose pH value is 7 and the dripping time is 20 s at the low speed of 800 r/min for 60 s at first, the medium speed of 1500 r/min for 30 s, and the high speed 4000 r/min for 60 s at last, with an acceleration rate of 100 r/(min∙s). The modified graphene film exists the maximum absorption peak at 421 nm in the visible wavelength band. The visible photo degradation rate of methylene blue by the modified graphene film is 34.4% for 4 h. Its catalytic principle is that the graphene film generats a strong oxidant • OH in the visible light, which can gradually degrade methylene blue and other pollutants into carbon dioxide and water, then the purpose of degradation is ultimately achieved.
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Received: 22 September 2017
Published: 11 July 2019
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