Water pollution from dyes utilized in textile, food, cosmetic and other manufacturing is a significant ecological concern with industry and scientists in search of biocompatible and more sustainable alternatives to guard the environment.
A brand new study led by Flinders University has discovered a novel solution to degrade and potentially remove toxic organic chemicals including azo dyes from wastewater, using a chemical photocatalysis process powered by ultraviolet light.
Professor Gunther Andersson, from the Flinders Institute for NanoScale Science and Technology, says the method involves creating metallic ‘clusters’ of just nine gold (Au) atoms chemically ‘anchored’ to titanium dioxide which in turn drives the response by converting the energy of absorbed UV light.
The gold nanocluster cocatalysts enhance the photocatalytic work of the titanium dioxide and reduce the time required to finish the response by an element of six, in accordance with a brand new journal article in Solar RRR.
“These kinds of heterogeneous semiconductor-mediated photocatalysis systems provide a major advantage over other advanced chemical processes,” says Professor Andersson, from the College of Science and Engineering.
“It could facilitate the mineralisation of a wide range of organic pollutants, like azo dyes, into water and carbon dioxide molecules with a high degradation efficiency.”
A wide range of physical, chemical and biological processes are currently used to remove carcinogenic and recalcitrant organic compounds from water.”
A big selection of chemical industries, including dye manufacture, textile and cosmetics production, release toxic and non-biodegradable dyes into the environment. Nearly half of the dyes utilized in the textile and dye industry are azo dyes. Methyl orange is widely used as a water-soluble azo dye.
With this in mind, the Flinders University nanotech researchers have also demonstrated the usefulness of this gold cluster cocatalyst and modified semiconductors for synthesis of the novel photocatalysis systems for degradation of methyl orange.
This study, just published in Applied Surface Science, tested the photocatalysis in a vortex fluidic device developed at Flinders University in Professor Colin Raston’s nanotechnology laboratory.
Co-author Flinders PhD Dr Anahita Motamedisade says traditional wastewater treatment methods often don’t effectively remove dangerous contaminants from wastewater.
“The rationale for that is that some chemicals, especially those with fragrant rings, are immune to chemical, photochemical and biological degradation, says Dr Motamedisade, who’s now a research fellow on the Centre for Catalysis and Clean Energy at Grifffith University.
“As well as, they generate dangerous by-products by oxidizing, hydrolysing, or undergoing other chemical reactions of synthetic dyes containing wastewater, that are detectable wherever they’re disposed of.
“We hope to construct onto these more sustainable and thorough photocatalytic degradation processes to assist completely remove the toxins and tackle this global problem.”
The research was inspired by Dr Motamedisade’s PhD research, part funded by Wine Australia, which incorporates higher ways to treat winery wastewater.
The article, “Enhanced Photocatalytic Degradation of Methyl Orange Using Nitrogen-Functionalized MesoporousTiO2 Decorated with Au9 Nanoclusters” (2024) by Anahita Motamedisade, Amir Heydari, Yanting Yin, Abdulrahman S Alotabi and Gunther G Andersson, has been published in Solar RRL (Wiley) DOI: 10.1002/solr.202300943 and “Au9 clusters deposited as co-catalysts on S-modified mesoporous TiO2 for photocatalytic degradation of methyl orange” (2024) by A Motamedisade, A Heydari, DJ Osborn, AS Alotabi and GG Andersson in Applied Surface Science DOI: 10.1016/j.apsusc.2024.159475.
For more details about story of how surface modification can efficiently control the agglomeration (size) and adsorption of Au clusters as co-catalysts take a look at the published work in Physical Chemistry Chemical Physics (2024, DOI: 10.1039/D3CP05353A).
Acknowledgements: This study was supported by the Australian Government and Wine Australia in addition to Microscopy Australia (formerly often known as AMMRF) and the Australian National Fabrication Facility (ANFF) and Flinders Microscopy and Microanalysis and Microscopy Australia at Adelaide Microscopy.
