A novel composite of zinc-based Metal Organic Framework embedded with SnO 2 Nanoparticle as a Photocatalyst for Methylene Blue Dye Degradation as well as Fluorometric probe for Nitroaromatic Compounds Detection

Abstract

A facile bottom up technique is opted for the synthesis of novel composite SnO2@Zn-BTC. This synthesized composite is fully characterized by Fourier Transform Infrared (FTIR) Spectroscopy, Powder X-Ray Diffraction (PXRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), and Elemental mapping techniques. Optical analysis is done using UV-Visible absorption spectroscopy and fluorescence studies. Further this composite is utilized for the first time to act as a photocatalyst for degradation of MB dye as a test contaminant under sunlight irradiation. This photocatalyst shows degradation efficiency of 89% within 100 min of exposure of sunlight. In addition to that the synthesized composite can be utilized as a fluorescence probe for detection of NACs via ‘turn-off” quenching response. This composite is extremely sensitive towards 3-NA in aqueous medium with quenching efficiency of 75.42 %, which is highest quenching rate till reported. There occurs no interference for detecting 3-NA in the presence of other NACs. The linear fitting of the Stern-Volmer plot for 3-NA shows large quenching constant (KSV) of 0.0115 ppb-1with correlation coefficient R2 = 0.9943 proves higher sensitivity of composite in sensing process. The outstanding sensitivity of composite for 3-NA is proved by low detection limit (LOD) of 25 ppb (0.18 µM). Photoinduced Electron Transfer (PET) and the Fluorescence Resonance Energy Transfer (FRET) are the mechanisms used for clarification of quenching response of PL intensity by NACs via Density functional theory (DFT) theoretical calculations and extent spectral overlap, respectively. Hence, synthesized composite is verified as multi-component system to act as excellent photocatalyst as well as fluorescent sensor.