Synthesis and application of tuneable carbon-silica composites from the microwave pyrolysis of waste paper for selective recovery of gold from acidic solutions

Konstantina Sotiriou, Nontipa Supanchaiyamat, Tengyao Jiang, Intuorn Janekarn, Andrea Muñoz García, Vitaliy L. Budarin, Duncan J. Macquarrie, Andrew J. Hunt*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Microwave pyrolysis bio-oil from waste paper and K60 silica gel has successfully been utilised to synthesise mesoporous carbon-silica composites with uniquely tuneable surface properties, where functionality and structural characteristics can be altered and even enhanced by curing at different temperatures. This temperature-dependence resulted in composites ranging from highly oxygenated polymerised bio-oil composites at 300 °C to aromatic carbonaceous materials covering the silica surface at 800 °C, making them attractive materials for gold recovery from mining wastewater. The composite materials exhibit exceptional ability and selectivity to recover gold from dilute solutions. Metal adsorption on the surface of these composites proceeded via both chemisorption and physisorption leading to the reduction of Au(iii) to Au(0), resulting in high recovery capacities for gold. Composite material prepared at 500 °C demonstrated the optimum combination of surface functionality and porosity, allowing for an adsorption capacity of 320 mg g-1 of gold and with 99.5% removal being achieved at concentrations mimicking those of real-life mine tailing wastes. All materials pioneered in this research display great potential as selective adsorbents for the recovery of gold from acidic media. This journal is

Original languageEnglish
Pages (from-to)25228-25238
Number of pages11
JournalRSC Advances
Issue number42
Early online date2 Jul 2020
Publication statusE-pub ahead of print - 2 Jul 2020

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© The Royal Society of Chemistry 2020

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