Green synthesis of mesoporous silica nanoparticles (MSNs) and its application on degradation of triclosan

Abstract

The widespread use of triclosan (TCS) across the globe poses a substantial threat to both human well-being and the ecosystem. This necessitates the development of eco-friendly adsorption techniques to address triclosan contamination in wastewater. This research aims to develop novel eco-friendly synthesis method using Syzygium jambos (SJ) leaf extract to produce small-sized Mesoporous Silica Nanoparticles (MSNs) by varying surfactant to silica ratio. Different ratios such as 1:50, 1:100, and 1:200 (1 mL of tetraethyl orthosilicate (TEOS) is equivalent to cetyltrimethylammonium bromide (CTAB) in mg) were explored without chemical stabilising agents or alcohol diluents. The synthesized materials were named as MSN1, MSN2, and MSN3. Characterisation studies using Field emission scanning electron microscopy (FE-SEM) showed that MSN3 exhibited smallest size of 30 ± 5nm. The physical, chemical and morphological properties were analysed for the materials using X-Ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDS), Zeta potential (ZP), Brunauer-Emmett-Teller (BET), Thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). Notably, the developed nanomaterial demonstrated noteworthy stability with a ZP of −33.1 mV and an impressive surface area of 545 m²/g. FT-IR peaks of biosorbent were obtained at 460, 800, and 975 1/cm. This confirms the existence of (Si–O–Si) bonds. The XRD results reveals that it possess amorphous nature of silica without any impurities. N₂ adsorption-desorption studies yielded a pore radius of 16.8 Å and volume of pores are 0.890 cc/g indicating its potential as an adsorbent and its utility for material functionalisation. The developed biosorbent exhibited enhanced adsorption properties for removal of triclosan from synthetic wastewater with 76 % removal at 0.5g/L dose of adsorbent.