摘要
本文利用磷酸水热法制备了多孔氮化碳(PCN-H)纳米材料,通过紫外-可见吸光光谱、扫描电子显微镜、X射线衍射、X射线光电子能谱和比表面积分析等多种手段表征催化剂的形貌、光学属性及结构特点等.在可见光照射下光催化降解除草剂莠去津,评价材料对莠去津的催化降解活性.分别测试最优化氮化碳材料在不同pH条件下对莠去津降解效率的变化,并分析催化剂用量和除草剂浓度对降解率的影响.结合活性物种捕获实验,阐述莠去津可见光降解的机理.通过材料表征结果分析,PCN-H表现为独特的多孔结构,比表面积分别是基础石墨型氮化碳(MCN)和磷酸浸泡氮化碳(PCN-S)的4.3倍和3.0倍.磷酸水热处理成功实现磷元素的掺杂,可见光利用率明显提高,1 h内即可将莠去津降解率从18.4%提升至45.7%.酸性条件有助于PCN-H对莠去津催化降解.在PCN-H可见光催化降解莠去津的过程中,光致空穴和超氧自由基发挥主要作用.该方法制备的材料光能利用率高,避免了金属催化剂自身对环境的潜在污染,酸性条件下降解更为高效,有助于减轻农药污染对农业生态环境及非靶标生物造成的负面影响.
To improve the photocatalytic efficiency, bulk carbon nitride(MCN) was treated by hydrothermal process with phosphoric acid in the present study. The resulting sample was denoted as PCN-H. The morphology, optical properties, and structure of prepared CN samples were characterized by UV-Vis spectrophotometer, scanning electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy, and BET analysis. The effect of the degradation of atrazine by PCN-H was investigated. The reaction mechanism was identified via active species trapping experiments.PCN-H with porous structure was successfully fabricated. The Brunauer-Emmett-Teller(BET) surface area of PCN-H is about 4.3 times and 3.0 times than that of MCN and PCN-S, respectively.Compared to PCN-S and MCN, the enhanced light absorption ability was obtained via P doping. The degradation percentage increased from 18.4% to 45.7% just in an hour. Acidic condition is conducive to high degradation efficiency. Light induced hole and superoxide radical are the main active species of PCN-H during the photocatalytic degradation of atrazine. The as-prepared PCN-H exhibits considerably high photocatalytic activity under visible light irradiation, which can also overcome contamination problem caused by metal catalyst. This work proved that PCN-H has great potential to be applied in alleviating negative effects of pesticide on agricultural ecological environment and nontarget organisms.
作者
刘雪
林樱楠
赵小燕
程森
蔡宪杰
于卫松
LIU Xue;LIN Yingnan;ZHAO Xiaoyan;CHENG Sen;CAI Xianjie;YU Weisong(Tobacco Research Institute of Chinese Academy of Agricultural Sciences,Qingdao,266101,China;Shanghai Tobacco Group Co.,Ltd.,Shanghai,200082,China)
出处
《环境化学》
CAS
CSCD
北大核心
2021年第12期3927-3935,共9页
Environmental Chemistry
基金
国家自然科学基金(31901921)
中国农业科学院烟草研究所青年科学基金(2019A01)
中国农业科学院科技创新工程(ASTIPTRIC06)资助。
关键词
氮化碳
掺杂
莠去津
光催化
机理
carbon nitride
doping
atrazine
photocatalysis
mechanism
