宽泛条件下光催化降解四环素的C_(3)N_(4)/TiO_(2)复合材料的性能研究  

Study on the properties of C_(3)N_(4)/TiO_(2) composites capable of photocatalytic tetracycline degradation under a wide range of conditions

作　　者：马晓佳 马同宇 赵益华 唐学静 靳凤先 郭盛祺 MA Xiaojia;MA Tongyu;ZHAO Yihua;TANG Xuejing;JIN Fengxian;GUO Shengqi(Tianjin Eco-City Water Investment and Construction Co.,LTD.,Tianjin,300467,China;School of Energy and Environmental Engineering,Hebei University of Technology,Tianjin,300401,China)

机构地区：[1]天津生态城水务投资建设有限公司,天津300467 [2]河北工业大学能源与环境工程学院,天津300401

出　　处：《环境化学》2023年第11期3789-3800,共12页Environmental Chemistry

基　　金：国家自然科学基金(21701125);中国博士后科学基金(2021T140512,2020M680896)资助.

摘　　要：本研究采用简便的原位水热法成功制备了g-C_(3)N_(4)/TiO_(2)复合材料.采用X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、傅立叶红外光谱(FTIR)、比表面积分析仪(BET)、紫外可见漫反射光谱仪(UV-Vis)、电化学工作站等对其物像、结构、形貌、光学特性和光电化学性能进行表征;以四环素(TC)为目标污染物在可见光下进行光催化降解实验,研究催化剂投加量、溶液pH、污染物浓度等不同条件对g-C_(3)N_(4)/TiO_(2)复合材料降解TC效果的影响,通过自由基捕获实验探讨其光催化降解TC的机理.结果表明,g-C_(3)N_(4)/TiO_(2)复合材料对TC的光催化降解效果均优于纯g-C_(3)N_(4)和TiO_(2),掺杂量为3%的CNT-3光催化活性最好,且有着优秀的矿化能力;复合材料能够在较少的投加量、较宽的pH范围以及较高的污染物浓度下高效降解TC,并且能够在反应环境中保持稳定,,OH自由基和空穴在反应体系中起主要作用.g-C_(3)N_(4)和TiO_(2)之间存在的Z型异质结,有效减少光生载流子复合,g-C_(3)N_(4)的引入不仅拓宽了TiO_(2)的光响应范围,而且促进了电荷转移和分离,提高了复合材料的光催化活性.In this work,g-C_(3)N_(4)/TiO_(2) composites were successfully prepared by simple in situ hydrothermal method.X-ray powder diffraction(XRD),scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),Fourier infrared spectroscopy(FTIR),specific surface area analyzer(BET),UV-visible diffuse reflection spectrometer(UV-Vis),electrochemical workstation were used to investigate the object image,structure,morphology,optical properties and photoelectric chemical properties were characterized;Tetracycline(TC)was used as the target pollutant to conduct photocatalytic degradation experiments under visible light.The influences of different conditions such as catalyst dosage,solution pH and pollutant concentration on the TC degradation effect of g-C_(3)N_(4)/TiO_(2) composites were studied.The mechanism of photocatalytic TC degradation was discussed through free radical capture experiments.The results show that the photocatalytic degradation effect of g-C_(3)N_(4)/TiO_(2) composites on TC is superior to that of pure g-C_(3)N_(4) and TiO_(2).The photocatalytic activity of CNT-3 doped with 3%is the best,and it has excellent mineralization ability.The composite can effectively degrade TC with less dosage,wider pH range and higher pollutant concentration,and can maintain stability in the reaction environment.·OH radical and h+play a major role in the reaction system.The existence of Z-type heterojunction between g-C_(3)N_(4) and TiO_(2) effectively reduces photogenerated carrier recombination.The introduction of g-C_(3)N_(4) not only broadens the photoresponse range of TiO_(2),but also promotes charge transfer and separation,which greatly improves the photocatalytic activity of the composites.

关 键 词：二氧化钛 光催化 四环素 Z型异质结 

分 类 号：X703[环境科学与工程—环境工程] O643.36[理学—物理化学] O644.1[理学—化学]