Porous TiO2 with a controllable bimodal pore size distribution from natural ilmenite
Porous TiO2 with a controllable bimodal pore size distribution from natural ilmenite
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来自天然钛铁矿的具有可控双峰孔径分布的多孔 TiO2
作者：
T. Tao;A. Glushenkov;Qi;Hui;Dan Zhou;Hongzhou Zhang;M. Boese;Sanly Liu;R. Amal;Y. Chen
钛铁矿 (FeTiO3) 是一种廉价、丰富的天然矿物，如果开发出合适的合成方法，它将成为生产多孔 TiO2 的完美前体。本文提出了一种结合球磨、高温退火、选择性化学浸出和最终空气煅烧一系列工艺步骤的新方法。所得的 TiO2 是一种具有双峰孔结构的多孔材料。孔径分布有两个明显的最大值，分别对应于小介孔（2-30 nm）和大介孔和大孔（集中在 50-80 nm 左右）。研究发现，退火步骤的持续时间可以改变每种类型的孔的贡献。较短的退火时间（0.5 h）导致优先形成2-30 nm范围内的孔隙，而在相对较长的退火时间（1.5 h）后，以50-80 nm为中心的孔隙主导了孔径分布。所获得的多孔金红石TiO2表现出比商业金红石TiO2粉末更好的光催化活性。
Ilmenite (FeTiO3) is an inexpensive abundant natural mineral and it would be a perfect precursor for the production of porous TiO2 if a suitable synthesis method was developed. A new method combining a series of processing steps of ball milling, high-temperature annealing, selective chemical leaching and final calcining in air is proposed in this paper. The resulting TiO2 is a porous material with a bimodal pore structure. The pore size distribution has two clear maxima corresponding to small mesopores (2–30 nm) and large meso- and macropores (centered at around 50–80 nm). It was found that the duration of the annealing step could alter the contribution of each type of pores. A short annealing time (0.5 h) lead to the preferential formation of pores within 2–30 nm while pores centered at 50–80 nm dominated the pore size distribution after a relatively long annealing (1.5 h). The obtained porous rutile TiO2 shows a better photocatalytic activity than that of a commercial rutile TiO2 powder.