Green synthesis of TiO2 nanoparticles from Syzygium cumini extract for photo-catalytic removal of lead (Pb) in explosive industrial wastewater

Abstract

<jats:title>Abstract</jats:title><jats:p>Green synthesis is a simple, non-toxic, economical and eco-friendly approach for the synthesis of nanoparticles. In the present work, nanoparticles of titanium dioxide (TiO<jats:sub>2</jats:sub> NPs) were synthesized using an aqueous solution of <jats:italic>Syzygium cumini</jats:italic> leaf extract as a capping agent. These green synthesized TiO<jats:sub>2</jats:sub> NPs were further evaluated for photo catalytic removal of lead from industrial wastewater. Obtained nanoparticles were characterized using: high-resolution scanning electron microscopy (HRSEM), high-resolution transmission electron microscopy (HRTEM), X-ray energy dispersive spectroscopy (EDS), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), dynamic light scattering (DLS) and Brunauer-Emmett-Teller (BET). Obtained results revealed that synthesized TiO<jats:sub>2</jats:sub> NPs possess spherical morphology with anatase phase with a large BET surface area of 105 m<jats:sup>2</jats:sup>/g. Photo catalytic studies of TiO<jats:sub>2</jats:sub> NPs for lead removal from explosive wastewater were performed in a self-designed reactor. Inductive coupled plasma spectroscopy (ICP) was used to determine the lead concentration. Obtained results witnessed 75.5% removal in chemical oxygen demand (COD) and 82.53% removal in lead (Pb<jats:sup>2+</jats:sup>). This application of green TiO<jats:sub>2</jats:sub> NPs is being explored for the first time.</jats:p>

Influence of Solvents' Polarity on the Physicochemical Properties and Photocatalytic Activity of Titania Synthesized Using Deinbollia pinnata Leaves

“…Scherer's equation (Lima et al, 2018 ), which relates the size of sub-micrometer crystallites in a solid to broadening of a sample peak in a diffraction pattern' illustrated as; D = K λ / β cos θ where ( D ) is average crystal size for the main broadening anatase peak; K = Scherrer's coefficient constant (0.89) which depend on the crystallite shape, λ = X-ray wavelength; β = full width at half maximum intensity (FWHM) of diffraction peaks in radians and θ = Bragg's angle, has been used to correlate the sample analysis reference pattern. The average crystallite size of the synthesized TiO 2 was 11 nm, which showed similarity with TiO 2 NPs synthesis using the extracts of Syzygium cumini , as reported by Sethy et al ( 2020 ). The order of their lattice parameters is as follows: the fraction from ethyl acetate (a = 3.79632, b = 9.52847) > n -hexane (a = 3.79223, b = 9.51600) > methanol (a = 3.79237, b = 9.51330), which indicates the qualitative merit for the fraction obtained by ethyl acetate [(0.149) > n -hexane fraction (0.136) >methanol extracts (0.121)].…”

Green synthesized titanium dioxide nanoparticles and their future applications in biomedicine, agriculture and industry

“…A similar result was noticed by Sundrarajan et al (2017) that used Morinda citrifolia leaves, while root extract of this plant led to larger NPs (Suman et al, 2015). TiO 2 NPs up to 20 nm were obtained also by using Syzygium cumini leaves extract (Sethy et al, 2020). Larger particles and more variable in shape were produced by using lemon (Citrus limon) extract, SEM analyses revealing TiO 2 structures of 20-200 nm (Hossain et al, 2019).…”

Green Synthesis and Applications of ZnO and TiO2 Nanostructures

“…Many other works have reported using plant extract mediating the synthesis of anatase TiO 2 NPs using the co-precipitation method [ 105 , 106 , 107 , 108 ]. However, as with traditional syntheses, green syntheses of the rutile phase are scarcer.…”

“…More recently, in addition to the usual applications in dye photodegradation, TiO 2 NPs synthesized by green approaches have also been used to remove Cr 6+ ions and chemical oxygen demand of real tannery effluents (efficiency of 82.26% and 76.48% under solar illumination) [ 95 ], the photoreduction of Cr 6+ ions (79.6% under UV irradiation) [ 208 ], removal of Pb from explosive industrial wastewater (82.53% removal after a 12 h treatment with UV light) [ 108 ], removal of total organic carbon and total nitrogen in refinery wastewater (efficiency of 32% and 67% under UV-C lighting, respectively) [ 209 ], and also organic compounds such as picric acid (100% under visible light at 120 min) [ 134 ], ornidazole antibiotic (67% efficiency under UV illumination after 100 min) [ 210 ], and ciprofloxacin (CIP) antibiotic (CIP removal of 90% after 60 min under UV-Vis illumination) [ 211 ]. The photodegradation of phenol (80% and 100% under irradiation with visible and UV light, respectively) [ 212 ], anthracene (96% efficiency a 4 h treatment with UV illumination) [ 213 ], photocatalytic generation of H 2 (360 µmol/g under UV-Vis irradiation) [ 214 ], and photocatalytic treatment against Enterococcus faecalis bacteria (99.2% efficiency under visible illumination) [ 118 ] was also achieved by using ZnO nanostructures produced by green synthesis.…”