Novel SnO2@Cu3(BTC)2 Composites as a Highly Efficient Photocatalyst and Fluorescent Sensor

Abstract

A novel SnO 2 @Cu 3 (BTC) 2 composite was synthesized using a quick and affordable bottom-up approach via impregnation of SnO 2 nanoparticles into the porous Cu 3 (BTC) 2 metal-organic framework (MOF). The photocatalytic degradation of the methylene blue (MB) dye has been studied for the rst time using this novel recyclable SnO 2 @Cu 3 (BTC) 2 composite. It was found that SnO 2 @Cu 3 (BTC) 2 composite photo catalytically degrades methylene blue (MB) dye with a degradation e ciency of 85.12% within 80 min under solar irradiation. The most appropriate bene t of this composite is the easy recyclability up to numerous cycles with retention of its photocatalytic activity. Therefore, this cheaper and greener composite photocatalyst is more suitable for large-scale industrial applications than the traditional photocatalysts employed in the degradation of MB dye. Furthermore, this composite has also been investigated as a uorescence sensor for the detection of nitroaromatic compounds (NACs). It was observed that the 88.2% quenching of the intense uorescent signal of this composite happens in the presence of 2,4,6-trinitrophenol (TNP) showing it incredibly selectivity towards TNP with no interference of other NACs. With a detection limit of 2.82 µM, this composite exhibits outstanding sensitivity towards TNP. The Stern-Volmer plot for TNP is linearly tted displays large quenching coe cient, correlation coe cient, and linear ranges K SV = 1.04x10 4 M -1 , R 2 = 0.9901, and 0-10 µM, respectively. This quenching response of this composite towards TNP was well-explained by the two mechanisms: one is photoinduced electron transfer (PET), and the other is uorescence resonance energy transfer (FRET), in addition to theoretical calculations based on density functional theory (DFT). Our ndings imply that the synthetic composite can be used as a superior uorescence sensor and photocatalyst. HighlightsUsing a bottom-up approach, a unique SnO 2 @Cu 3 (BTC) 2 composite has been prepared.Experiments demonstrate that this composite degrade 85.12% of methylene blue (MB) dye within 80 minutes.Additionally, this composite also sensitively and selectively detects 2,4,6-trinitrophenol (TNP) in water via turn-off quenching response.The turn-off quenching response of this composite can be explained by photo-induced Electron Transfer (PET) and uorescence Resonance Energy Transfer (FRET) mechanisms.Theoretical density functional theory (DFT) calculations were done to provide strong support to the experimental results.