Smart Mn<sup>7+</sup> Sensing via Quenching on Dual Fluorescence of Eu<sup>3+</sup> Complex-Modified TiO<sub>2</sub> Nanoparticles

oleh: Wenbin Yang, Siqi Niu, Yao Wang, Linjun Huang, Shichao Wang, Ketul C. Popat, Matt J. Kipper, Laurence A. Belfiore, Jianguo Tang

Format: Article
Diterbitkan: MDPI AG 2021-12-01

Deskripsi

In this work, titania (TiO<sub>2</sub>) nanoparticles modified by Eu(TTA)<sub>3</sub>Phen complexes (ETP) were prepared by a simple solvothermal method developing a fluorescence Mn<sup>7+</sup> pollutant sensing system. The characterization results indicate that the ETP cause structural deformation and redshifts of the UV-visible light absorptions of host TiO<sub>2</sub> nanoparticles. The ETP also reduce the crystallinity and crystallite size of TiO<sub>2</sub> nanoparticles. Compared with TiO<sub>2</sub> nanoparticles modified with Eu<sup>3+</sup> (TiO<sub>2</sub>-Eu<sup>3+</sup>), TiO<sub>2</sub> nanoparticles modified with ETP (TiO<sub>2</sub>-ETP) exhibit significantly stronger photoluminescence under the excitation of 394 nm. Under UV excitation, TiO<sub>2</sub>-ETP nanoparticles showed blue and red emission corresponding to TiO<sub>2</sub> and Eu<sup>3+</sup>. In addition, as the concentration of ETP in TiO<sub>2</sub> nanoparticles increases, the PL intensity at 612 nm also increases. When ETP-modified TiO<sub>2</sub> nanoparticles are added to an aqueous solution containing Mn<sup>7+</sup>, the fluorescence intensity of both TiO<sub>2</sub> and ETP decreases. The evolution of the fluorescence intensity ratio (I<sub>1</sub>/I<sub>2</sub>) of TiO<sub>2</sub> and ETP is linearly related to the concentration of Mn<sup>7+</sup>. The sensitivity of fluorescence intensity to Mn<sup>7+</sup> concentration enables the design of dual fluorescence ratio solid particle sensors. The method proposed here is simple, accurate, efficient, and not affected by the environmental conditions.