Inducing piezoelectricity in distorted rutile TiO <sub>2</sub> for enhanced tetracycline hydrochloride degradation through photopiezocatalysis
Taotao Xia, Lizhen Lu, Haoyu Zhang, Jinghui Wang, Zonghe Huang, Hongyang Wang, Weiyi Yang, Shuang Gao, Qi Li
Abstract
Various material design strategies have been developed to enhance the photocatalytic performance of TiO<sub>2</sub>. However, no report is available on the application of the photopiezocatalysis strategy on TiO<sub>2</sub> due to its lack of piezoelectricity. Here we developed a low temperature molten salt etching process to create rutile TiO<sub>2</sub> nanoparticles by etching [MgO<sub>6</sub>] octahedrons away from MgTiO<sub>3</sub> by molten NH<sub>4</sub>Cl, during which a lattice distortion occurred in TiO<sub>2</sub>. The lattice distortion broke the structure symmetry of rutile TiO<sub>2</sub> and subsequently endowed these rutile TiO<sub>2</sub> nanoparticles an unusual piezoelectric response with the maximum effective piezoelectric coefficient (<em>d<sub>33</sub></em>) of ~ 41.6 pm/V, which had not previously been found in TiO<sub>2</sub> photocatalysts. Thus, the photopiezocatalysis strategy was applied for the first time to enhance the photocatalytic performance of these TiO<sub>2</sub> nanoparticles. The creation of lattice distortion to induce piezoelectricity could be extended to other photocatalysts that the photopiezocatalysis strategy has not been applied to and may generate novel functionalities for various technical applications.