Synergistic catalytic effects of visible light and graphene on bioleaching of chalcopyrite

Abstract

The effects of graphene and visible light on chalcopyrite bioleaching was studied using Acidithiobacillus ferrooxidans. The results indicated that graphene and visible light could significantly accelerate chalcopyrite dissolution. The concentration of dissolved copper in the light system without graphene was 24.8% higher than the control group without light and graphene. The copper solubilization rate in the dark system with graphene was slightly higher than the control group. The copper solubilization rate of the group with light and 1.0 g L⁻¹ graphene was the highest in comparison to others, and it was 50.3% higher than the control group. It was shown that the enhancing effect of the synergy catalysis was much more significant than when only using a single catalytic method. Bioleaching results, X-ray diffraction (XRD), cyclic voltammetry (CV), scanning electron microscopy (SEM) and elemental X-ray microanalysis (EDS) analysis indicated that the synergistic catalytic effect of graphene and light could primarily be attributed to the promotion of Fe³⁺/Fe²⁺ cycling and inhibition jarosites formation on the chalcopyrite surface.