Abstract: Using zinc acetate dihydrate, urea, ammonia and purified diatomite as raw materials, diatomite supported nitrogen-doped nano-zinc oxide catalyst (N-ZnO/DE) was prepared by sol-gel method. The structure, morphology and composition of the samples were characterized and analyzed by use of testing techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-Visible diffuse reflectance spectrometer (UV-Vis DRS) and fluorescence spectrometer (PL). Taking methylene blue (MB) as the target pollutant, the photocatalytic activity and stability of diatomite loaded nitrogen-doped ZnO nanoparticles on MB under visible light irradiation were investigated. The research results show that N-ZnO /DE can effectively broaden the spectral response range and improve photocatalytic efficiency. After 150 min photocatalytic oxidation, the maximum decolorization rate of MB in N-ZnO/DE catalytic reaction system reaches 86%, and the reaction is in accordance with the first-order kinetic model. ·OH and ·O-2 are found to be the main active substances for photocatalytic degradation of MB by the free radical capture experiment, and free radical oxidation is the main pathway for MB decolorization reaction.

Key words: resource and environment engineering; photocatalysis; zinc oxide; nitrogen-doped; spectral characteristics; diatomite

摘要： 以二水乙酸锌、尿素、氨水及提纯后硅藻土为原料，采用溶胶-凝胶法制备了硅藻土负载氮掺杂纳米氧化锌催化剂（N-ZnO/DE）；采用扫描电子显微镜（SEM）、X射线衍射仪（XRD）、紫外-可见漫反射光谱仪（UV-Vis DRS）和荧光光谱仪（PL)等测试技术对制备出的样品结构、形貌及组成进行表征分析；以亚甲基蓝（MB）为目标污染物，考察硅藻土负载氮掺杂纳米ZnO在可见光照射下对MB的光催化活性及稳定性。 研究结果表明：N-ZnO/DE可有效拓宽光谱响应范围，提升光催化效率；经150 min光催化氧化反应后，N-ZnO/DE催化反应体系中MB最大脱色率达86%；自由基捕获实验发现·OH及·O-2为光催化降解MB的主要活性物质，且自由基氧化是MB脱色反应的主要路径。

关键词: 资源环境工程；光催化剂；氧化锌；氮掺杂；光谱特性；硅藻土