Hu Yulong, Liu Hongfang, Kong Xiaodong, Guo Xingpeng
J Nanosci Nanotechnol. 2014 May;14(5):3532-7. doi: 10.1166/jnn.2014.8021.
A series of N-doped TiO2 nanoparticle powders have been prepared by the sol-gel method using triethylamine as N precursor. The effect of calcination temperatures on the quality of the as-prepared samples was studied and an annealing treatment was introduced to improve further the quality of the as-prepared sample. The visible light photocatalytic activities of the samples were evaluated by decomposition of methyl orange (MO) in water. The calcination temperature plays a key role in determining the quality of N-doped TiO2 nanoparticle powders. The enhancement of calcination temperatures facilitates the crystallization of N-doped TiO2 powders and the elimination of surface organic residues, but promotes the loss of doping N and the agglomeration of nanoparticles and results in low N doping level and large particle sizes. The N-doped TiO2 sample (NT-300) calcined at 300 degrees C in air for 3 h produced the maximum visible light photocatalytic activity. The annealing treatment of NT-300 at its calcination temperature could improve the crystallinity, remove effectively the surface organic residues, keep nanoparticles in smaller size, and retain the doping N, therefore improving the visible light photocatalytic activity significantly.
采用溶胶-凝胶法，以三乙胺为氮源前驱体，制备了一系列氮掺杂二氧化钛纳米颗粒粉末。研究了煅烧温度对所制备样品质量的影响，并引入退火处理进一步提高所制备样品的质量。通过水中甲基橙（MO）的分解来评估样品的可见光光催化活性。煅烧温度在决定氮掺杂二氧化钛纳米颗粒粉末的质量方面起着关键作用。提高煅烧温度有助于氮掺杂二氧化钛粉末的结晶以及表面有机残留物的消除，但会促进掺杂氮的损失和纳米颗粒的团聚，导致氮掺杂水平低和颗粒尺寸大。在空气中300℃煅烧3小时制备的氮掺杂二氧化钛样品（NT-300）具有最大的可见光光催化活性。在煅烧温度下对NT-300进行退火处理可以提高结晶度，有效去除表面有机残留物，使纳米颗粒保持较小尺寸，并保留掺杂氮，从而显著提高可见光光催化活性。
