The　development　of　highly　selective,　cost-effective,　and　energy-efficient　electrocatalysts　is　critical　for　carbon　dioxide　reduction　reaction　(CO2RR)　to　produce　high-value　products.　Herein,　we　propose　a　facile　strategy　to　obtain　F,　N　co-doped　carbon-coated　iron　carbide　(Fe3C)　nanoparticles　by　using　biomolecule　guanine　and　hexadecafluorophthalocyanine　iron　as　raw　materials.　Remarkably,　this　method　involves　only　one-step　pyrolysis　and　does　not　require　any　guiding　agent　or　sacrificial　template.　Benefiting　from　the　advantageous　surface　microenvironment　adjustments　achieved　through　graphitic　N　(GN)　and　F　co-doping,　Fe3C@NF-G-1000　demonstrates　exceptional　efficacy　in　the　electroreduction　of　CO2　to　carbon　monoxide　(CO)　with　an　impressive　Faradic　efficiency　(FEco)　up　to　98%　at　the　potential　of　−0.55　V　(vs.　reversible　hydrogen　electrode　(RHE)).　Furthermore,　it　delivers　a　remarkable　current　density　of　up　to　−43　mA·cm−2　and　exhibits　virtually　no　current　attenuation　over　a　span　of　20　h　within　the　flow　cell.　Insights　from　density　functional　theory　(DFT)　calculations　reveal　that　the　composite　structure　of　GN　and　F　co-doped　graphitic　layer　and　Fe3C　exhibits　different　electron　density　distributions　from　that　of　iron　carbide　nanoparticles.　This　is　attributed　to　the　synergistic　effect　of　the　composite　structure　leading　to　the　enrichment　of　electrons　in　the　graphite　layer　on　the　surface,　which　contributes　to　the　stability　of　the　key　reaction　intermediate　*COOH,　thus,　resulting　in　an　enhanced　catalytic　activity　and　efficiency.　Overall,　this　work　introduces　a　new　and　promising　approach　to　the　design　of　green　and　low-cost　carbon-coated　metal　materials　for　CO2　reduction　reactions.[Figure　not　available:　see　fulltext.].　©　2024,　Tsinghua　University　Press.