Surface modification of phosphate ion to promote photocatalytic recovery of precious metals

Abstract

Photocatalytic recovery, a novel precious metal recycling technology, dedicates to solving the environmental and energy consumption problems caused by traditional technologies. The activation of molecular oxygen (O2) is one of the most critical steps in the whole process. Herein, we regulated the different adsorption intensity of oxygen on the surface by designing phosphate (PO43−) modified titanium oxide (TiO2). The results show that the adsorption of oxygen on the photocatalyst surface is gradually enhanced, which effectively improves the dissolution rate of precious metals. PO43− modification increased the photocatalytic dissolution rate of gold (Au) by 2.8 times. The photocatalytic activity of other precious metals dissolution (such as palladium (Pd), platinum (Pt), rhodium (Rh), ruthenium (Ru) and iridium (Ir)) was also significantly improved. It is applied to the recovery of precious metals from spent catalysts and electronic devices to significantly promote the recovery efficiency. This indicates the direction for designing more efficient photocatalysts for precious metal recovery.