Chemistry

Graphene oxide and chitosan sponges found to be 10 times more efficient at removing gold from electronic waste

SEM images of Au3+ extraction and reduction by GO/chitosan sponge. Au3+ is displayed in yellow. Credit: Kou Yan

A team of chemists and materials scientists from the National University of Singapore, in collaboration with colleagues from the University of Manchester in the UK and Guangdong University of Technology in China, have developed a type of sponge made of graphene oxide and chitosan. Used to extract gold from electronic waste.

In a paper published in the Proceedings of the National Academy of Sciences, the group describes how they made the sponge and how well it performed during testing.

Previous research has shown that removing gold, silver and other metals from unwanted electronics as a way to recycle them is a difficult and often dirty job. Yields are often reduced and various toxic pollutants are produced.

In this new study, the research team has discovered a way to remove gold that is cheaper, cleaner, and more efficient than traditional methods.

The research team deliberately selected these materials. Both have been used to extract gold from other materials. Additionally, graphene has a demonstrated ability to absorb ions, and chitosan (a natural biopolymer) is a well-known reducing agent, in this case used to catalytically convert gold ions into solid form. It was used.

The two materials were made into a composite by self-assembling chitosan on two-dimensional graphene flakes. This process creates sites on the material that can bind gold ions. After the gold ions are absorbed into the graphene, chitosan converts them into a solid gold state, making them easy to collect. The research team says the process is highly efficient.

The team tested the sponge using real e-waste provided by a recycling company. Electronic waste arrived in the form of a solution mixture. That is, it is crushed and mixed into a liquid with other substances present in electronic devices. Pre-treatment measurements showed a gold concentration of 3 ppm.

The newly developed sponge was able to extract approximately 17 g/g of Au3+ ions and just over 6 g/g of Au+ ions. The researchers claim that such amounts are about 10 times higher than other known extraction processes.

Further information: Kou Yang et al. Graphene/chitosan nanoreactor for ultrafast and accurate recovery and catalytic transformation of gold from e-waste, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2414449121

© 2024 Science X Network

Source: Graphene oxide and chitosan sponges found to be 10 times more efficient at removing gold from e-waste (October 26, 2024) https://phys.org/news/2024-10-graphene Retrieved from -oxide- on October 27, 2024 chitosan sponge shop.html

This document is subject to copyright. No part may be reproduced without written permission, except in fair dealing for personal study or research purposes. Content is provided for informational purposes only.

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button