摘要
以钛酸四丁酯(C16H36O4Ti)为Ti源,尿素((NH2)2CO)为N源,硅藻土(Diatomite)为载体,采用溶胶凝胶法制备硅藻土负载氮掺杂二氧化钛改性纳米材料(N-TiO2/Diatomite).利用SEM、XRD、XPS、FT-IR、UV-Vis DRS对其进行系列特性表征及可见光催化性能分析,探究Microcystin-LR初始浓度对光催化的影响,分析其降解动力学和降解途径.结果表明,硅藻土负载优化了N-TiO2分子的分散性,形成了链条型纳米孔隙球状结构;N元素掺杂、硅藻土负载不影响材料晶型,晶粒粒径减小至11.39 nm;Si、N分别与TiO2成键;光响应强度和范围红移,可见光活性显著提升.以优化制备条件(350℃煅烧、掺N的物质的量分数为8%)的改性N-TiO2/Diatomite材料可见光催化降解Microcystin-LR,当初始质量浓度为1 mg·L^-1的Microcystin-LR水溶液反应6 h后降解率可达95.0%,矿化率为83.9%;反应符合准一级动力学方程,速率常数k为0.453 3 h^-1.
Nanomaterials modified by nitrogen-doped titanium dioxide(N-TiO2/Diatomite)were prepared by sol-gel method.The photocatalyst was taken tetrabutyl titanate(C16H36O4Ti) as Ti source, urea((NH2)2CO) as N source and Diatomite as carrier.SEM, XRD, XPS, FT-IR and UV-Vis DRS were used to characterize its serial characteristics and analyze its visible light catalytic performance, to explore the influence of Microcystin-LR initial concentration on photocatalysis, and to analyze its degradation kinetics and degradation pathway.The results showed that diatomite load optimized the dispersibility of N-TiO2 molecule, and formed the nanometer pore spherical structure.N doped and diatomite load did not affect the crystal shape of the material, and the grain size decreased to 11.39 nm.Si and N bond with TiO2 respectively.The intensity and range of light response were redshifted, and the visible light activity was significantly increased.Microcystin-LR was degraded by visible light catalytic degradation of modified N-TiO2/Diatomite materials under optimized preparation conditions(calcination at 350 ℃, 8% N doped).When the Microcystin-LR aqueous solution with initial concentration of 1 mg·L^-1 was irradiated for 6 h, the degradation rate reached 95.0%, and the mineralization rate was 83.9%.The reaction conforms to pseudo-first-order kinetic equation, and the rate constant k is 0.453 3 h^-1.
作者
陈俊伟
李丽丽
郑育毅
吴春山
王菲凤
CHEN Jun-wei;LI Li-li;ZHENG Yu-yi;WU Chun-shan;WANG Fei-feng(College of Environmental Science and Engineering,Fujian Normal University Fuzhou 350007,China;Key laboratory of Resource Cycle and Pollution Control of Fujian Province,Fujian Normal University,Fuzhou 350007,China;Fujian Academy of Building Research Institute Co.,Ltd.Fuzhou 350028,China)
出处
《福建师范大学学报（自然科学版）》
CAS
北大核心
2019年第6期51-59,共9页
Journal of Fujian Normal University：Natural Science Edition
基金
福建省科技厅高校产学合作项目(2016Y4002)
福建省科技厅社会发展引导性项目(2018Y0022)
