Hubei Provincial Key Laboratory of Green Materials for Light Industry, Hubei University of Technology, Wuhan 430068, China.
Institute for Catalysis, Hokkaido University, N21, W8, 001-0021 Sapporo, Japan.
J Nanosci Nanotechnol. 2020 Feb 1;20(2):1278-1287. doi: 10.1166/jnn.2020.16970.
Octahedral anatase particles (OAPs) belonging to faceted titania photocatalysts exhibit one of the highest photocatalytic activities among various titania photocatalysts, probably due to hindered recombination of charge carriers resulting from low content of defects (recombination centers). In this study, OAPs have been examined for oxidative decomposition of acetic acid, dehydrogenation of methanol and bacteria inactivation. OAPs were prepared from partly protonated potassium nanowires by hydrothermal reaction (HT) at various experimental conditions, i.e., the influences of HT temperature and content of reaction reagents were studied in detail. The morphology, composition and crystal structure of the products were characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS) and time-resolved microwave conductivity (TRMC) method. It was found that all parameters during HT influenced simultaneously the morphology of obtained products, and even slight change in one of them could result in significant change in the properties, and thus photocatalytic activities. Moreover, it was shown that titania morphology was a key-factor for photocatalytic activity for decomposition of both organic compounds and microorganisms. Although, an imperfection in octahedral shape (semi-OAPs) did not influence the efficiently for decomposition of organic compounds, it had tremendous negative impact on antimicrobial performance, probably due to hindered adsorption of bacterial cells on the photocatalyst surface (preferential on {101} facets).
八面体锐钛矿颗粒（OAPs）属于有棱钛光催化剂，在各种钛光催化剂中表现出最高的光催化活性之一，这可能是由于缺陷（复合中心）含量低导致载流子复合受到阻碍。在这项研究中，研究了 OAPs 对乙酸的氧化分解、甲醇的脱氢和细菌失活的作用。通过水热反应（HT），从部分质子化的钾纳米线制备 OAPs，在不同的实验条件下，详细研究了 HT 温度和反应试剂含量的影响。通过扫描电子显微镜（SEM）、粉末 X 射线衍射（XRD）、透射电子显微镜（TEM）、X 射线光电子能谱（XPS）、漫反射光谱（DRS）和时间分辨微波电导率（TRMC）法对产物的形貌、组成和晶体结构进行了表征。结果发现，HT 过程中的所有参数都会同时影响产物的形貌，甚至其中一个参数的微小变化都可能导致性能甚至光催化活性的显著变化。此外，还表明钛形态是光催化分解有机化合物和微生物活性的关键因素。尽管八面体形状的不完美（半-OAPs）并不影响有机化合物的分解效率，但它对抑菌性能有巨大的负面影响，这可能是由于细菌细胞在光催化剂表面的吸附受到阻碍（优先在{101}面）。
