Soft and Hard Templates Assisted Synthesis Mesoporous CuO/g-C3N4 Heterostructures for Highly Enhanced and Accelerated Hg(II) Photoreduction under Visible Light
Mohammad W. Kadi, Reda M. Mohamed, Adel A. Ismail, Detlef W. Bahnemann
Journal of Colloid and Interface Science
Herein, triblock copolymer surfactant (F127) and mesoporous silica (MCM-41) as soft and hard templates were employed to synthesize of mesoporous CuO/g-C3N4 heterostructures with large surface areas for Hg(II) photoreduction in existence of formic acid as a holes sacrificial. TEM image for mesoporous CuO/g-C3N4 indicated that CuO NPs are homogeneously distributed with spherical shape in particle size ∼ 5 nm onto the surface of g-C3N4. Mesoporous 2%CuO/g-C3N4 heterostructure was achieved a high Hg(II) photoreduction rate of 628.74 µmolg-1h-1 and high photoreduction efficiency of ∼100% within 50 min compared with the pure either mesoporous CuO NPs (130.11 µmolg-1h-1, 21%) and g-C3N4 (88.54 µmolg-1h-1, 14%). The highest Hg(II) photoreduction rate achieved was 628.74 µmolg-1h-1, which is 4.83 and 7.1 magnitudes stronger than mesoporous CuO NPs and g-C3N4. The excellent photocatalytic performance of mesoporous CuO/g-C3N4 heterostructures for Hg(II) photoreduction is referred to highly dispersed mesoporous CuO NPs with small particle size onto g-C3N4, narrow bandgap, large surface area, a rapid transfer of Hg(II) ions and HCOOH to easily reach the active sites due to the facile penetration through the mesostructure, thus promoting the utilization of porous structure of CuO/g-C3N4 heterostructures for efficient diffusion of Hg(II) ions. The intense interaction between mesoporous CuO NPs and porous g-C3N4 confirms the durability of the CuO/g-C3N4 heterostructures during recyclability for five times.
Absorption, Materials, Quantitation