Fabrication of carbon and sulphur-doped nanocomposites with seaweed polymer carrageenan as an efficient catalyst for rapid degradation of dye pollutants using a solar concentrator

Abstract

Here we demonstrate direct use of sulphate rich seaweed polysaccharides Carrageenans namely kappa (κ-), iota (ι-) and lambda (λ-) as source of sulfur and carbon doping in photocatalyst TiO2. During TiO2 synthesis in presence of sulphate rich carrageenan leaves mainly residual carbon and sulfur doping resulted in highly active photocatalyst. Evaluation of dye degradation pattern shows rapid degradation of Reactive Black-5, Methylene Blue & Methyl Orange dyes using modified TiO2 nanocomposites in different light sources. Robust dye degradation was achieved between 1-4 h under daylight. Whereas, use of solar concentrator reduced the degradation time of MB and RB-5 to <5 min and MO solution was turned colorless within 20 min. Present study elaborates effect of seaweed carrageenans in inducing heteroatom like sulfur and residual carbon on photodegradation of industrially important dyes.

Fabrication, functionalization and performance of doped photocatalysts for dye degradation and mineralization: a review

“…Moreover, doping of TiO 2 with nonmetal such as nitrogen, carbon and sulphur has had excellent effects in improving the photocatalytic activity of TiO 2 . For example, Chaudhary et al (2016) have synthesized seaweed heteroatom-doped TiO 2 NPs wherein the remnant C-doping and S-doping from the seaweed carrageenan precursor in the TiO 2 composite implied larger surface areas for the effective degradation of dyes (namely methylene blue, reactive black-5 and methyl orange) in less than 20 min in daylight conditions. Chaudhary et al (2016) explained the enhanced daylight dyedegrading photocatalytic activity of the λ-S-TiO 2 nanomaterial on the basis of the large surface area resulting from the graphite like carbon residue, greater S-content and suitable anatase crystallinity.…”

“…For example, Chaudhary et al (2016) have synthesized seaweed heteroatom-doped TiO 2 NPs wherein the remnant C-doping and S-doping from the seaweed carrageenan precursor in the TiO 2 composite implied larger surface areas for the effective degradation of dyes (namely methylene blue, reactive black-5 and methyl orange) in less than 20 min in daylight conditions. Chaudhary et al (2016) explained the enhanced daylight dyedegrading photocatalytic activity of the λ-S-TiO 2 nanomaterial on the basis of the large surface area resulting from the graphite like carbon residue, greater S-content and suitable anatase crystallinity. Yun et al (2015) synthesized core-shell-type TiO 2 @ mercaptopropyl-functionalized silica particles in view to enhance the photocatalytic characteristics of TiO 2 .…”

Tree gum-based renewable materials: Sustainable applications in nanotechnology, biomedical and environmental fields

“…Thickener, gelling agent, stabilizer, emulsifier (Williams et al, 2011) -drug delivery, microcapsules and microspheres (Li et al, 2014) binders (Williams et al, 2011;Zia et al, 2017) nanocomposite for photodegradation of dyes (Chaudhary et al, 2016) flame-retardant (Xue et al, 2017) hydrogel for wound healing (Nair et al, 2016) Xanthan gum…”

Entrapment of distilled palmarosa (cymbopogon martinii) wastes in alginate beads for adsorptive removal of methylene blue from aqueous solution

“…The agitation rate is same for all experiments. The parameters such as adsorbent concentration (1-20 g/L), initial dye concentration (10-150 mg/L), temperature (298-328 K), pH (2)(3)(4)(5)(6)(7)(8)(9)(10), and also kinetic studies were carried out with a contact time (5-1440 min) and these parameters varied during different sets of batch experiments. After adsorption, the separation processes of the solid-liquid phases at PDWAB-MB solutions were carried out by centrifuging at 5000 rpm for 10 min, and the residual MB concentrations were measured by means of UV/Vis spectrophotometer (Sytronics, Ahmedabad, India) at the wavelength of 665 nm.…”

“…Despite stringent environmental regulations, industries are still lack comprehensive wastewater treatment methods. Annually >500 tons of nondegradable textile color wastes are being disposed to natural streams without adequate treatments . Methylene blue (MB), which is classified as a basic dye has wider application including colouring paper, dyeing cottons, wools, temporary hair colorant, coating for paper stock etc.…”