Abstract：Using self-made g-C3N4, graphene oxide (GO) and TiO2 as raw materials, the g-C3N4/rGO/TiO2 photocatalyst with reduced graphene oxide (rGO) as photo-generated electron transport medium was successfully prepared through electrostatic adsorption and hydrothermal reduction processes, and the morphologies, structures and optical properties of the catalysts were characterized by SEM, X-ray diffraction (XRD), UV-Vis-DRS and photocurrent density test. Ammonia nitrogen solution with nitrogen concentration of 50mg/L was used as the simulated raw water, and the pH of ammonia nitrogen solution was adjusted to 9~10. The photocatalytic property of this photocatalyst for ammonia nitrogen removal was studied under the irradiation of a xenon lamp. The SEM results showed that g-C3N4/rGO/TiO2 photocatalytic material was coated with TiO2 as the coating layer, the XRD pattern of the composite exhibited both diffraction peaks of TiO2 and g-C3N4, and the DRS spectrum showed that the optical absorption capacity of the composite photocatalyst was significantly enhanced in the visible region. Experiments on ammonia nitrogen removal showed that the composite photocatalyst with raw material GO:g-C3N4=1:10possessed best photocatalytic performance in ammonia nitrogen degradation, and the average removal rate of ammonia nitrogen was 96.80%. From the results of the electron paramagnetic resonance (EPR), it was speculated that the degradation mechanism was that the superoxide anion radical and hydroxyl radical generated by the composite catalyst oxidize the adsorbed NH3 directly on the surface of the material under light irradiation, and rGO played a conduction role as the photocatalytic material's photo-generated charges transmission medium.
曹雅洁, 岳秀萍, 李厚芬, 薛帅, 孔鑫, 李慧, 曹昉. g-C3N4/rGO/TiO2光催化材料降解模拟污水中氨氮[J]. 中国环境科学, 2020, 40(10): 4370-4377.
CAO Ya-jie, YUE Xiu-ping, LI Hou-fen, XUE Shuai, KONG Xin, LI Hui, CAO Fang. The photocatalytic property of g-C3N4/rGO/TiO2 photocatalyst for ammonia nitrogen degradation in simulated wastewater. CHINA ENVIRONMENTAL SCIENCECE, 2020, 40(10): 4370-4377.
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