Prominent COF, g-C 3 N 4 , and Their Heterojunction Materials for Selective Photocatalytic CO 2 Reduction.

New heterojunction materials (HJs) were synthesized in-situ by molecularly bonding the monomers of a triazine-based covalent organic framework (bulk COF) on the template of exfoliated carbon nitride (g-C₃N₄). The photocatalysts reduced carbon dioxide to carbon monoxide in aqueous dispersions under UV irradiation. The g-C₃N₄ showed production of 6.50 μmol CO g⁻¹ h⁻¹ and the bulk COF of 2.77 μmol CO g⁻¹ h⁻¹. The CO yield was evaluated in sustainability photoreduction cycles and their CO₂ uptake capacity and isosteric heat of adsorption were estimated. All the heterojunction photocatalysts obtained ameliorated CO production rates compared to the bulk COF. Finally, the influence of the Pt co-catalyst on the photocatalytic activities was determined without the addition of any sacrificial agent, and the COF:g-C₃N₄ heterojunction with the ratio of 1:10 was proven to be a photocatalytic system with an optimum and selective, CO yield of 7.56 μmol g⁻¹ h⁻¹. [ABSTRACT FROM AUTHOR]