Andronic Luminita, Ghica Daniela, Stefan Mariana, Mihalcea Catalina Gabriela, Vlaicu Aurel-Mihai, Karazhanov Smagul
Product Design, Mechatronics and Environment Department, Transilvania University of Brasov, Eroilor 29, 500036 Brasov, Romania.
National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania.
Nanomaterials (Basel). 2022 Jul 26;12(15):2563. doi: 10.3390/nano12152563.
Special attention has recently been paid to surface-defective titanium dioxide and black TiO with advanced optical, electrical, and photocatalytic properties. Synthesis of these materials for photodegradation and mineralization of persistent organic pollutants in water, especially under visible radiation, presents interest from scientific and application points of view. Chemical reduction by heating a TiO and NaBH mixture at 350 °C successfully introduced Ti defects and oxygen vacancies at the surface of TiO, with an increase in the photocatalytic degradation of amoxicillin-an antibiotic that is present in wastewater due to its intense use in human and animal medicine. Three TiO samples were prepared at different annealing temperatures to control the ratio between anatase and rutile and were subjected to chemical reduction. Electron paramagnetic resonance investigations showed that the formation of surface Ti defects in a high concentration occurred mainly in the anatase sample annealed at 400 °C, contributing to the bandgap reduction from 3.32 eV to 2.92 eV. The reduced band gap enhances visible light absorption and the efficiency of photocatalysis. The nanoparticles of ~90 m/g specific surface area and 12 nm average size exhibit ~100% efficiency in the degradation of amoxicillin under simulated solar irradiation compared with pristine TiO. Mineralization of amoxicillin and by-products was over 75% after 48 h irradiation for the anatase sample, where the Ti defects were present in a higher concentration at the catalyst's surface.
最近，具有先进光学、电学和光催化性能的表面缺陷二氧化钛和黑色二氧化钛受到了特别关注。从科学和应用的角度来看，合成这些材料用于光降解和矿化水中的持久性有机污染物，尤其是在可见光辐射下，具有重要意义。通过在350°C下加热TiO和NaBH混合物进行化学还原，成功地在TiO表面引入了Ti缺陷和氧空位，提高了阿莫西林的光催化降解率。阿莫西林是一种抗生素，由于在人类和动物医学中的大量使用，存在于废水中。制备了三个在不同退火温度下的TiO样品，以控制锐钛矿和金红石的比例，并进行化学还原。电子顺磁共振研究表明，高浓度表面Ti缺陷的形成主要发生在400°C退火的锐钛矿样品中，导致带隙从3.32 eV降低到2.92 eV。减小的带隙增强了可见光吸收和光催化效率。与原始TiO相比，比表面积约为90 m/g、平均尺寸为12 nm的纳米颗粒在模拟太阳辐射下对阿莫西林的降解效率约为100%。对于锐钛矿样品，在照射48小时后，阿莫西林及其副产物的矿化率超过75%，该样品在催化剂表面存在较高浓度的Ti缺陷。
