Hydrothermal enhanced etching of Ni for direct recovery of gold flakes from electronic waste†

IF 9.3 1区化学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Green Chemistry Pub Date : 2025-03-05 DOI:10.1039/d4gc06607c

Shuling Shen , Yu Chu , Ziwei Feng , Zheng Du , Huixin Xiu , Xinjuan Liu , Shuning Xiao , Zhihong Tang , Jing Li , Xun Wang

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引用次数: 0

Abstract

The content of precious Au in electronic waste (e-waste) is often tens to hundreds of times higher than that in natural ore deposits. Current technologies for recovering Au from e-waste mainly involve a two-step process of leaching and reduction, which are accompanied by high energy consumption, greenhouse gas emissions and toxic agents. In this article, we present an efficient, environmentally friendly and scalable hydrothermal catalysis technique for the one-step recovery of Au solid flakes from e-waste. The recovery process avoids the use of strong acids, alkalis, or toxic agents and operates under mild conditions (80–130 °C). During the hydrothermal reaction, Ni beneath the Au layer is selectively etched by hydroxyl radicals (˙OH), allowing the Au layer to be directly peeled off and recovered. Au solid flakes with a high recovery rate (up to 99.2%) and high purity (96.6%, without a further purification process) are obtained, eliminating the need for any additional reduction process. This research emphasizes the crucial role of both hydrothermal conditions and catalysts (e.g. TiO₂) in promoting the generation of ˙OH. The results of an techno-economic analysis and life cycle assessment indicate that this hydrothermal catalysis technique is a low-cost and environmentally friendly method for large-scale Au recovery from e-waste.

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来源期刊

Green Chemistry 化学-化学综合

CiteScore

16.10

自引率

7.10%

发文量

677

审稿时长

1.4 months

期刊介绍： Green Chemistry is a journal that provides a unique forum for the publication of innovative research on the development of alternative green and sustainable technologies. The scope of Green Chemistry is based on the definition proposed by Anastas and Warner (Green Chemistry: Theory and Practice, P T Anastas and J C Warner, Oxford University Press, Oxford, 1998), which defines green chemistry as the utilisation of a set of principles that reduces or eliminates the use or generation of hazardous substances in the design, manufacture and application of chemical products. Green Chemistry aims to reduce the environmental impact of the chemical enterprise by developing a technology base that is inherently non-toxic to living things and the environment. The journal welcomes submissions on all aspects of research relating to this endeavor and publishes original and significant cutting-edge research that is likely to be of wide general appeal. For a work to be published, it must present a significant advance in green chemistry, including a comparison with existing methods and a demonstration of advantages over those methods.