ABSTRACT
Colloidal route synthesis of quaternary compound CZTS (Cu2ZnSnS4) has been anticipated with an inimitable combination of coordinating ligands and solvents using the hot injection technique. CZTS is recognized as one of the worthiest materials for photo-voltaic/catalytic applications due to its exclusive properties (viz., non-toxic, economical, direct bandgap, high absorbance coefficient, etc.). This paper demonstrates the formation of crystalline, single-phased, monodispersed, and electrically passivated CZTS nanoparticles using a distinctive combination of ligands viz. oleic acid (OA)-trioctylphosphine (TOP) and butylamine (BA)-trioctylphosphine (TOP). Detailed optical, structural, and electrochemical studies were done for all CZTS nanoparticles, and the most efficient composition was found using ligands butylamine and TOP. CZTS nanocrystals were rendered hydrophilic via surface-ligand engineering, which was used for photocatalysis studies of organic pollutants. Malachite green (MG) and rhodamine 6G (Rh) for water remediation have great commercial prospects. The unique selling proposition of this work is the rapid synthesis time (~ 45 min) of colloidal CZTS nanocrystals, cost-effective ligand-exchange process, and negligible material wastage (~ 200 µl per 10 ml of pollutant) during photocatalytic experiments.
Subject(s)
Environmental Pollutants , Nanoparticles , Water , Butylamines , Ligands , SolventsABSTRACT
An exemplary vision to understand the fundamental role of metal-doped multi-components system such as Au/Ag doped CZTS (Cu2ZnSnS4) nanocrystals encourages the non-vacuum approach for the best performing photocatalyst. Hydrophilic nanoparticles (Au/Ag and CZTS) are allowed to amalgamate under NTP atmosphere, eradicating the prerequisite for high-end equipment. The potential of Au and Ag-doped CZTS nanoparticles was speculated using various optical and structural characterizations. The absorption range of CZTS nanoparticles lies in the visible range, while Au/Ag doping slightly red-shifts the absorption range, considered the desirable state for photocatalysis. The synthesized nanoparticles are highly monodispersed with â¼15-35 nm particle size for Ag, Au, and CZTS. Photocatalysis is a discernible scheme for treating wastewater containing dyes, textile effluents, chemicals, and heavy metals. Here, we strive to use these ex-situ synthesized nanomaterials as photocatalysts, where the real textile waste (collected from industrial outlets), dyes, and heavy metal (chromium (VI)) have been photo-reduced after scrutinizing the finest combination of Ag or Au doped CZTS. Au-CZTS shows superior catalytic activity with an efficiency of 99.7% with a rate constant of 0.2 min-1 (while Ag-CZTS shows 90% efficiency with a rate constant of 0.07 min-1); hence, used for real textile waste and heavy metal (Chromium VI) photo-reduction. The maximum efficiency achieved for textile-1, textile-2, and Cr (VI) reductions is 80%, 70%, and 97%, respectively. The nanocrystals are highly stable and recyclable, tested for 15 repeated cycles. These studies pave the way for developing cost-effective, environmentally-friendly, durable, and selective semiconductor-metal (Au/Ag) hybrid heterostructures as visible-light-driven photocatalysts for wastewater remediation.
Subject(s)
Metals, Heavy , Nanoparticles , Wastewater , Nanoparticles/chemistry , Coloring Agents/chemistry , TextilesABSTRACT
Dye-sensitized solar cells (DSSCs) have become the subject matter of significant interest for the research and due to their urge in the field of energy conservation. The safe supply of energy is welfare of human life. However, as an unattainable power-energy conservation source, also depletion of fossil fuels is an unfortunate mandate and, definitely it is imminent. To encounter this critical issue of energy, non-conventional sources of energy have gained lots of attention, especially solar energy because it's a device that converts light-energy directly to electrical-energy without harming the environment. DSSCs provides a reliable and a cheap alternative for different kinds of Photovoltaics. The spectacle realization of Dye-sensitized-solar-cell is typically relying on photosensitizer (Dye), electrolyte and metal oxide semiconductor. A natural dye has become most credible alternative for such expensive and rare inorganic/chemical sensitizers, due to its lower cost, easy fabrication, eco-friendly and abundance of raw material. Also, DSSC has easily implemented technology with significant efficiency. This review paper enlightens the emergence, operation/fabrication, components and development of DSSCs using natural photo-sensitizers and factors that affect the stability.
