섬유, 식품, 화장품 및 기타 제조 과정에 사용되는 염로로 인한 수질 오염은 주요 환경 문제로 대두되고 있다. 이에 산업계와 과학자는 환경을 보호하기 위해 생물학적으로 적합하고, 지속가능한 대안을 모색하고 있다. 

플린더스 대학(Flinders University)이 주도한 새로운 연구는, 자외선을 활용한 화학적 광촉매 과정을 통해 폐수에서 아조 염료를 포함한 독성 유기 화학물질을 분해하고, 제거할 수 있는 방법을 발견했다.  

이 과정은 이산화티타늄에 화학적으로 고정된 아홉 개의 금(Au) 원자로 구성된 금속 ‘클러스터’를  생산하고, 이를 통해 흡수된 자외선 에너지를 변환시켜 반응을 유도한다. 

『Solar RRL』 저널에 따르면, 금 나노 클러스터 공촉매(共觸媒)는 이산화티타늄의 광촉매 작업을 향상시키고, 반응 완료 시간을 6배 단축시킨다. 

군터 앤더슨(Gunther Andersson) 플린더스 나노스케일 과학기술 연구소(Flinders Institute for NanoScale Science and Technology)의 교수는 “이러한 유형의 이종(異種) 반도체 매개 광촉매 시스템은 다른 첨단 화학 공정에 비해 상당한 이점을 제공하며, 높은 분해 효율로 아조 염료와 같은 다양한 유기 오염물질을 물과 이산화탄소 분자로 광물화하는 것을 촉진한다”고 설명했다.

아나히타 모탐디사데(Anahita Motamedisade) 공동저자이자 플린더스 대학 박사는 “전통적인 폐수 처리 방법은 종종 폐수에서 위험한 오염 물질을 효과적으로 제거하지 못한다”며 “이는 일부 화학 물질, 특히 방향족 고리를 가진 화학 물질이 화학적, 광화학적, 생물학적 분해에 저항력이 있기 때문”이라고 말했다. 

모탐디사데 박사는 “플린더스 대학 연구팀은 지속 가능하고 확실한 광촉매 분해 공정을 구축해 이를 기반으로 독소를 완전히 제거하고, 세계적인 문제를 해결하는 데 도움이 되기를 바란다”고 말했다. 

이 연구는 와인 호주(Wine Australia)의 일부 자금 지원을 받은 모탐디사데 박사의 박사 학위 연구에서 영감을 받았으며, 『어플라이드 서피스 사이언스(Applied Surface Science)』 학술지에 게재됐다.

[원문보기] 

Nano solution for removing toxic dyes

Water pollution from dyes used in textile, food, cosmetic and other manufacturing is a major ecological concern with industry and scientists seeking biocompatible and more sustainable alternatives to protect the environment.

A new study led by Flinders University has discovered a novel way 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 process involves creating metallic ‘clusters’ of just nine gold (Au) atoms chemically ‘anchored’ to titanium dioxide which in turn drives the reaction 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 complete the reaction by a factor of six, according to a new journal article in Solar RRR.

“These types of heterogeneous semiconductor-mediated photocatalysis systems provide a significant advantage over other advanced chemical processes,” says Professor Andersson.

“It can facilitate the mineralisation of a large range of organic pollutants, like azo dyes, into water and carbon dioxide molecules with a high degradation efficiency.”

A variety of physical, chemical and biological processes are currently used to remove carcinogenic and recalcitrant organic compounds from water.

A wide range of chemical industries, including dye manufacture, textile and cosmetics production, release toxic and non-biodegradable dyes into the environment. Nearly half of the dyes used 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 do not effectively remove dangerous contaminants from wastewater.

“The reason for this is that some chemicals, especially those with aromatic rings, are resistant to chemical, photochemical and biological degradation, says Dr Motamedisade, who is now a research fellow at the Centre for Catalysis and Clean Energy at Grifffith University.

“In addition, they generate dangerous by-products by oxidizing, hydrolysing, or undergoing other chemical reactions of synthetic dyes containing wastewater, which are detectable wherever they are disposed of.

“We hope to build onto these more sustainable and thorough photocatalytic degradation processes to help 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 includes better 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 information about story of how surface modification can efficiently control the agglomeration (size) and adsorption of Au clusters as co-catalysts check out the published work in Physical Chemistry Chemical Physics (2024, DOI: 10.1039/D3CP05353A).

[출처 = Flinders University(https://news.flinders.edu.au/blog/2024/03/20/nano-solution-for-removing-toxic-dyes/) / 2024년 3월 20일]

[번역 = 박원희 기자]