In situ no-slot joint integration of half-metallic C(CN)3 cocatalyst into g-C3N4 scaffold: An absolute metal-free in-plane heterosystem for efficient and selective photoconversion of CO2 into CO

An absolute metal-free in-plane heterosystem consisting of g-C3N4 as scaffold and embedded half-metallic C(CN)(3) as cocatalysts was conceptually designed for photoconversion of CO2. The no-slot joint between half-metallic C(CN)(3) and g-C3N4 through covalent bonding generates a unique two-dimensional, pi-conjugated hybrid structure, allowing obstacle-free transferring of the photogenerated electrons in g-C3N4 into C(CN)(3) via an intrinsic driving force. Our theoretical calculations together with the in-situ Fourier transform infrared spectra indicate that the most negative charge distribution and binding energy with CO2 for C(CN)(3) allow outstanding capture and chemical activation capacity toward CO2, and subsequently enable the optimized heterosystem to exhibit highly efficient and selective photocatalytic reduction of CO2 into CO, 7.8 and 1.9 times those produced with pristine and Pt-modified g-C3N4, respectively. The no-slot joint of organic half-metal cocatalysts with g-C3N4 may open up new opportunities for metal-free, polymer-based photocatalytic systems for CO2 conversion and solar fuel generation.