Facile synthesis of iron and cerium co-doped g-C3N4 with synergistic effect to enhance visible-light photocatalytic performance

A novel visible-light-driven Fe and Ce bimetallic co-doped g-C3N4 (Fe-Ce/CN) photocatalyst was successfully fabricated by a straightforward method. Experimental results indicated that no matter in the single - pollutant system or mixed pollutants system containing Cr(VI) and an organic dye, Fe-Ce/CN exhibits super photocatalytic activity. It is mainly caused by the synergistic effect of Fe and Ce ions. Fe inserted into the lattice of g-C3N4 could narrow the band gap and inhibit combination of photogenerated electron-hole pairs. More importantly, the existence of Fe and Ce would improve the redox cycle with each other which is benefit for further increasing charge separation, light absorption and quantum efficiency. Furthermore, the controlled experiments and electron spin resonance (ESR) were performed to identify the relevant reactive species. Possible photocatalytic process of simultaneously removing mixed pollutants and mechanism were proposed. In general, this work provides a facile method to improve the photocatalytic activity of photocatalyst.