Aqueous Photocatalytic Recycling of Gold and Palladium from Waste Electronics and Catalysts

Abstract

Gold and palladium are the most widely used precious metal materials in the field of electronic devices and industrial catalysis. How to realize the green recycling of gold and palladium is important and challenging. In this work, we found that gold and palladium in wastes, such as electronic devices and industrial catalysts, can be completely dissolved and recycled by photocatalysis. Gold and palladium are oxidized to the ionic state in water, which does not involve strong acids, strong alkalis, toxic cyanides, or an organic medium. More interestingly, the dissolution of gold and palladium in different halogen aqueous solutions has special selectivity, which depends on the coordination stability constants between gold and palladium with halide ions. Therefore, gold and palladium can be selectively dissolved in iodine ion solution and bromine ion solution, respectively, then gold and palladium can be obtained by a one-step reduction. This work opens up a new direction for optimizing the photocatalytic dissolution technology and promoting the green recycling of precious metals.

Oxygen vacancies assist a facet effect to modulate the microstructure of TiO2 for efficient photocatalytic O2 activation

“…S4† displays that the Ti 2p peaks splits into Ti 2p 3/2 (458.41 eV) and Ti 2p 1/2 (464.73 eV), and the peaks at around 530 eV should belong to O 1s, which is in agreement with reported data of TiO 2 . 27,28…”

“…S4 † displays that the Ti 2p peaks splits into Ti 2p 3/2 (458.41 eV) and Ti 2p 1/2 (464.73 eV), and the peaks at around 530 eV should belong to O 1s, which is in agreement with reported data of TiO 2 . 27,28 The morphology of the samples was observed by scanning electron microscopy (SEM, Fig. 1a, b and Fig.…”

Recovering precious metals from spent catalysts by peroxydisulfate-based advanced oxidation process

“…35 . In addition, it was possible that the solvency capability of the PDS/NaCl solvent was insufficient to dissolve Pt and Rh at a temperature of 60 °C and an atmospheric pressure 36 . Leaching experiments of PMs in PDS/NaCl system.…”

Sustainable and Selective Modern Methods of Noble Metal Recycling

“…Alternatively, exploiting kinetic control seems a very promising approach. For example, in organic solvents [116] or water [117] based TiO 2 ‐photocatalytic system, which results in different metals selectively dissolving at different times (f).…”