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.