Templated synthesis of CuCo2O4-modified g-C3N4 heterojunctions for enhanced photoreduction of Hg2+ under visible light

Abstract Background The accumulation of mercury (II) ions (Hg2+) in wastewater causes critical impacts on human health and the whole environment. Methods This study report an efficient synthesis of CuCo2O4/g-C3N4 p-n heterojunction by templated growth via triblock copolymer F-127 and mesoporous silica MCM-41 for enhanced photoreduction of Hg2+. Significant Findings The 22.6 nm CuCo2O4 nanoparticles were anchored on g-C3N4 at minor content (0.5−2.0 wt. %) as observed by TEM analysis. The formed heterojunctions exhibited mesoporous surface textures with high specific surface areas. In addition, the visible-light harvesting of g-C3N4 was improved by adding CuCo2O4 due to the reduction of the bandgap energy from 2.77 to 2.17 eV. The complete visible-light photocatalytic reduction of Hg2+ utilizing 1.5 wt.% CuCo2O4-modified g-C3N4 was realized with a tremendous rate of 286.5 µmol min−1 after dose tuning at 1.5 gL−1. The enhanced catalytic presentation of this innovative CuCo2O4/g-C3N4 is denoted to the significant separation of photoinduced carriers through the p-n heterojunction's interface. The bearable photocatalytic reduction of Hg2+ for five cycles was also established for the regenerated photocatalyst.