A novel green approach for Au/Pt recovery from lean solutions through photodeposition and alkaline leaching on WO3 nanoparticles

Abstract

The efficient extraction and recycling of noble metal resources have become an inevitable trend for sustainable socio-economic development. Traditional methods suffer from lengthy processes, high energy consumption, and serious environmental hazards, necessitating the development of new, environmentally friendly, cost-effective, and efficient methods for noble metal extraction. This study primarily employs a photochemical method to reduce and enrich low-concentration Au/Pt noble metal solutions on the surface of the WO₃ semiconductor, followed by alkali leaching and acidification steps to achieve Au/Pt extraction and WO₃ recycling. It can complete the enrichment of noble metals within 20 min, with a deposition efficiency of over 99% and a total recovery efficiency of over 93%, suitable for noble metal concentrations ranging from 0.01 to 10 mM. The extracted Pt particles have a diameter of approximately 5 nm, and the Au particles have a diameter of about 60 nm, both with a purity of 99.9%. The acid-regenerated WO₃ semiconductor can be reused cyclically, maintaining stable performance. This study establishes a novel technology for the recycling and recovery of noble metals from lean solutions based on semiconductor photochemistry, holding significant scientific and practical value for noble metal resource recycling.