The main component of natural gas is methane, whose combustion contributes to global warming. As such, sustainable, energy efficient, nonfossil-based methane production is needed to satisfy current energy demands and chemical feedstocks. In this article, we have constructed a metal-free porous polyketone (TPA-DPA PPK) with donor-acceptor (D-A) groups with an extensive pi-conjugation by facile Friedel-Crafts acylation reaction between triphenylamine (TPA) and pyridine-2,6-dicarbonyl dichloride (DPA). TPA-DPA PPK is a metal-free catalyst for visible-light driven CO2 photoreduction to CH4, which can be used as a solar fuel in the absence of any cocatalyst and sacrificial agent. CH4 production (152.65 ppm g(-1)) is similar to 5 times greater than that of g-C3N4 under the same test conditions. Charge-density difference plots from excited-state time-dependent density functional theory (TD-DFT) calculations indicate a depletion and accumulation of charge density among the donor/acceptor functional groups upon photoexcitation. Most notably, binding energies from DFT demonstrate that H2O is more strongly bound with the pyridinic nitrogen group than CO2, which shed insight into mechanistic pathways for photocatalytic CO2 reduction.
CO2 conversion to hydrocarbon fuels; Water splitting for hydrogen generation; Quantum dot devices; Dye sensitized solar cells; Environmental remediation; Synthesis of functional nanomaterials; CO2 연료전환; 수소생산을 위한 광전기화학적 물분해; 양자점 태양전지; 염료감응 태양전지; 공해물질 저감연구; 기능성 나노소재 개발