摘要
分别以硝酸锌,醋酸锌,氯化锌和硫酸锌为锌源采用水热法制备了纳米ZnO,通过X射线衍射仪(XRD)和透射电子显微镜(TEM)对ZnO进行了表征,结果表明:四类锌源制备的ZnO均为六方晶系的纤锌矿结构,尺寸在23.9～62.6 nm.在紫外光照射下以罗丹明B(Rhodamine B,RhB)和2,4-二氯苯酚(2,4-Dichlorophenol,2,4-DCP)的光催化降解为探针反应,研究了介质pH条件和催化剂用量等对光催化反应的影响,表明pH=6.2和催化剂用量为0.4 g.L-1条件下以硝酸锌为锌源制备的ZnO活性最好,60 min内RhB褪色完全,120 min内2,4-DCP降解率达到97%.通过总有机碳(TOC)的测定,发现6 h内RhB矿化率达到95.2%.采用辣根过氧化物酶(POD)法和苯甲酸荧光光度法分别测定了体系中H2O2和羟基自由基(.OH)的变化,表明其光催化反应机理涉及.OH历程.
ZnO nanoparticles were prepared by hydrothermal method with zinc nitrate,zinc acetate,zinc chloride and zinc sulfate,respectively.The synthesized ZnO nanoparticles were characterized by X-ray diffraction（XRD） and transmission electron microscopy（TEM）.The results show that all structure of ZnO is hexagonal wurtzite and average diameter is 23.9-62.6 nm.The photocatalytic degradation of Rhodamine B（RhB） and 2,4-Dichlorophenol（2,4-DCP） under UV light is used as probe reactions to evaluate photocatalytic activities of ZnO nanoparticles.Effects of pH and catalyst dosage are explored.Under conditions of pH 6.2 and catalyst dosage 0.4 g·L-1;ZnO prepared with zinc nitrate has a best activity which faded RhB completely in 60 min and degradated 2,4-DCP 97% after 120 min.By the measurement of TOC,RhB can be mineralizated 95.2% after 6 h.H2O2 and ·OH radical are detected by horseradish peroxidase spectro-photometry and benzoic acid flurescence analysis method.The results indicate that photocatalytic degradation process mainly referred to ·OH radical mechanism.
出处
《三峡大学学报（自然科学版）》
CAS
2011年第4期75-80,共6页
Journal of China Three Gorges University：Natural Sciences
基金
国家自然科学基金(20877048)
湖北省创新群体项目(2009CDA020)
湖北省高等学校优秀中青年科技创新团队计划(T200703)
关键词
ZNO
光催化
降解
有机污染物
ZnO
photocatalysis
degradation
organic pollutants
