Decatungstate-Driven Photocatalytic Pathways for Sustainable and Cleaner Recovery of Precious Metals.

The recovery of precious metals from waste streams is crucial for sustainable resource utilization but remains hindered by traditional methods involving high toxicity, energy consumption, and environmental pollution. Here, we present a photocatalytic strategy employing hydrothermally synthesized decatungstate ([WO]) homogeneous ion catalysts to achieve simultaneous oxidation and reduction of precious metals under ambient conditions. This innovative approach integrates solvent-controlled reaction pathways, enabling efficient dissolution and recovery of precious metals from diverse waste sources, including electronic waste (e-waste), platinum membrane electrodes, and platinum-containing catalysts. The decatungstate catalyst exhibits exceptional performance, with an apparent quantum yield of 0.027%-nearly double that of commercial TiO (0.014%)-and achieves recovery efficiency of 80%-100% for platinum, surpassing 21 tested photocatalysts. The process adheres to a solid-phase dissolution model and remains against ionic interference. Time-dependent density functional theory (TD-DFT) calculations corroborate experimental UV-vis spectra, while electron-hole pair analyses elucidate atomic and molecular contributions to photocatalytic activity. Density functional theory (DFT) further validates the thermodynamic feasibility of the reaction pathways. By combining high efficiency, ambient operational conditions, and scalability, this work establishes decatungstates as a sustainable benchmark for green precious metal recovery, addressing the limitations of traditional methods and advancing innovation in resource circularity.