Inducing piezoelectricity in distorted rutile TiO2 for enhanced tetracycline hydrochloride degradation through photopiezocatalysis

Abstract

Various material design strategies have been developed to enhance photocatalytic performance of TiO2. However, no report is available on applications of the photopiezocatalysis strategy on TiO2 due to its lack of piezoelectricity. Here we developed a low-temperature molten salt etching process to create rutile TiO2 nanoparticles by etching [MgO6] octahedrons away from MgTiO3 by molten NH4Cl, during which a lattice distortion occurred in TiO2. The lattice distortion broke the structure symmetry of rutile TiO2 and subsequently endowed these rutile TiO2 nanoparticles with an unusual piezoelectric response with the maximum effective piezoelectric coefficient (d33) of ~41.6 pm/V, which had not previously been found in TiO2 photocatalysts. Thus, the photopiezocatalysis strategy was applied for the first time to enhance the photocatalytic performance of these TiO2 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.

Keywords

• tio2
• molten salt etching process
• photocatalysis
• piezocatalysis
• photopiezocatalysis