Fullerene modification of Ag3PO4 for the visible-light-driven degradation of acid red 18

Abstract

This work synthesized a C₆₀/Ag₃PO₄ composite via the modification of Ag₃PO₄, by incorporation of an acid treated fullerene (C₆₀), with the aim of improving the photocatalytic activity and stability of Ag₃PO₄. XRD, SEM, Raman, XPS, PL, and UV-vis DRS were used to study the structural characteristics of the obtained photocatalysts. Acid red 18 (AR18) was adopted to evaluate the photocatalytic activity of the as-prepared photocatalysts under visible light irradiation. The results showed that C₆₀ was successfully hybridized with Ag₃PO₄, and the C₆₀/Ag₃PO₄ composite showed higher photocatalytic activity and better stability than Ag₃PO₄. The enhancement of photocatalytic activity strongly depended on the amount of C₆₀ on Ag₃PO₄, and the optimum amount was found to be a weight ratio of 2% (C₆₀/Ag₃PO₄). Superoxide radical anions (O₂˙⁻) were confirmed to be the main participants in the degradation of AR18, determined by the active free radical capture experiments, and O₂˙⁻ production by 2% C₆₀/Ag₃PO₄ was nearly 1.5 times higher than that by Ag₃PO₄. The superior photocatalytic activity and stability of C₆₀/Ag₃PO₄ could be attributed to the presence of C₆₀, which can not only be used as an electron acceptor for photo-induced electrons from Ag₃PO₄ to reduce the recombination of photo-induced electron–hole pairs, but also to improve O₂˙⁻ production during the photocatalysis process.