A Carbon Nitride/Fe Quaterpyridine Catalytic System for Photostimulated CO₂-to-CO Conversion with Visible Light

Abstract

Efficient and selective photostimulated CO₂-to-CO reduction by a photocatalytic system consisting of an iron-complex catalyst and a mesoporous graphitic carbon nitride (mpg-C₃N₄) redox photosensitizer is reported for the first time. Irradiation in the visible region (λ ≥ 400 nm) of an CH₃CN/triethanolamine (4:1, v/v) solution containing [Fe(qpy)(H₂O)₂]²⁺ (qpy = 2,2':6',2'':6'',2''-quaterpyridine) and mpg-C₃N₄ resulted in CO evolution with 97% selectivity, a turnover number of 155, and an apparent quantum yield of ca. 4.2%. This hybrid catalytic system, comprising only earth abundant elements, opens new perspectives for solar fuels production using CO₂ as a renewable feedstock.