Effect of calcination on structure and photocatalytic property of N-TiO2/g-C3N4@diatomite hybrid photocatalyst for improving reduction of Cr(VI)
Effect of calcination on structure and photocatalytic property of N-TiO2/g-C3N4@diatomite hybrid photocatalyst for improving reduction of Cr(VI)
复制标题
焙烧对N-TiO2/g-C3N4@硅藻土杂化光催化剂结构和光催化性能的影响以提高Cr(VI)还原率
DOI：
10.1016/j.envpol.2018.10.121
复制
发表时间：
2019
影响因子：
8.9
通讯作者：
Sheng Jiawei
中科院分区：
文献类型：
--
作者：
Sun Qing;Hu Xiaolong;Zheng Shuilin;Zhang Jian;Sheng Jiawei
以四氯化钛为前驱体，尿素为氮碳源，通过简单的浸渍法制备了N-二氧化钛/g-C3N4@硅藻土(NTCD)复合材料。考察了焙烧温度对催化剂结构、表面性质和光催化活性的影响。并用X射线衍射仪、透射电子显微镜、X射线光电子能谱、傅立叶变换红外光谱和紫外-可见漫反射吸收光谱对所得粉末进行了表征。通过可见光照射(λ>； 400 nm)还原水中的六价铬来评价其光催化活性。结果表明，在500 °C焙烧2 h的NTCD-500催化剂中，锐钛矿晶型中15~30 nm的纳米二氧化钛粒子均匀沉积在硅藻土表面，并且纳米二氧化钛表面附着着厚度为0.92 nm的g-C3N4。N掺杂的TiO_2和g-C_3N_4掺杂的催化剂在可见光区具有协同增强的响应，减小了NTCD-500的带隙(如 = 3.07 eV)。在5 h内，催化剂对六价铬的光催化活性接近100%，高于P25、粗二氧化钛@硅藻土和g-C3N4@硅藻土。
The N-TiO2/g-C3N4@diatomite (NTCD) composite has been prepared through a simple impregnation method, using titanium tetrachloride as precursor and urea as nitrogen-carbon source. Then the effects of calcination temperature on structure, surface property and photocatalytic activity of the catalysts were investigated. And XRD, TEM, XPS, FTIR and UV–vis diffuse adsorption spectroscopy were used to characterize the obtained powders. The photocatalytic activity of the NTCD was evaluated through the reduction of aqueous Cr (VI) under visible light irradiation (λ> 400 nm). The results demonstrated that the nano-TiO2particles ranging from 15 to 30 nm in the crystal of anatase are well deposited on the surface of diatomite in the NTCD-500 which calcined at 500 °C for 2 h. Furthermore, the g-C3N4with the lay thickness of 0.92 nm was attached to the surface of nano-TiO2. The N-doped TiO2and g-C3N4doped catalysts could co-enhance response in the visible light region and reduce band gap of NTCD-500 (Eg = 3.07 eV). And the NTCD-500 sample exhibited nearly 100% removal rate within 5 h for photocatalytic reduction of Cr (VI) which was higher activity than P25, crude TiO2@diatomite and g-C3N4@diatomite.