[111]-/{101}晶面共暴露的锐钛矿型TiO2纳米晶的制备及可提高的光催化性能

本文以层状钛酸H1.07Ti1.73O4为前驱体，以不同含量的HF溶液为形貌控制剂，在温和的水热条件下(120~180 ℃)采用一锅法合成了共暴露111]-/{101}晶面的方块状为主的锐钛矿型TiO2纳米晶；对制备的xHF-T180 (x = 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 mL)锐钛矿型TiO2纳米晶的晶体结构、形貌、微观结构、比表面积、元素电子态、光学性能和电荷迁移行为进行了表征；并对其光催化降解MB性能进行了评价. 研究结果表明，与CM-TiO2和其他xHF-T180锐钛矿型TiO2纳米晶相比，2.5HF-T180显示了最高的k值(0.0165 min-1)，分别是Blank (0.0009 min-1)、CM-TiO2 (0.0083 min-1)、0.5HF-T180 (0.0126 min-1)、1.0HF-T180 (0.0113 min-1)、1.5HF-T180 (0.0142 min-1)、2.0HF-T180 (0.0130 min-1)和3.0HF-T180 (0.0123 min-1)样品的18.33、1.99、1.31、1.46、1.16、1.27和1.34倍. 2.5HF-T180显示了最高的光催化活性可以归因于其最小的颗粒尺寸、最大的比表面积、最弱的荧光光谱强度和最小的电阻的协同效应. 本研究为合成具有较高光催化性能的锐钛矿型TiO2纳米晶以处理有机染料废水提供了新思路.

Synthesis of [111]-/{101} facets co-exposed anatase TiO2 nanocrystals with improved photocatalytic performance

Cuboid anatase TiO2 nanocrystals with co-exposed 111]-/{101} facets were synthesized by one-pot method under mild hydrothermal conditions (120~180 ?C) using layered titanate H1.07Ti1.73O4 as precursor and different amounts of HF as morphology-controlling agent. The crystal structure, morphology, microstructure, surface area, electronic states, optical properties and charge migration behavior of xHF-T180 (x = 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 mL) anatase TiO2 nanocrystals were characterized, and their photocatalytic degradation of MB was evaluated. The results show that, compared with CM-TiO2 and other xHF-T180 anatase TiO2 nanocrystals, 2.5HF-T180 shows the highest k value (0.0165 min-1), which is 18.33, 1.99, 1.31, 1.46, 1.16, 1.27 and 1.34 times that of Blank (0.0009 min-1), CM-TiO2 (0.0083 min-1), 0.5HF-T180 (0.0126 min-1), 1.0HF-T180 (0.0113 min-1), 1.5HF-T180 (0.0142 min-1), 2.0HF-T180 (0.0130 min-1), and 3.0HF-T180 (0.0123 min-1), respectively. The highest photocatalytic activity of 2.5HF-T180 can be attributed to the synergistic effect of its smallest particle size, largest specific surface area, weakest fluorescent intensity and smallest electrical resistance. This study provides a new idea for the synthesis of anatase-type TiO2 nanocrystals with high photocatalytic performance for the treatment of organic dye wastewater.