It　is　a　challenging　task　to　overcomes　the　bottleneck　of　N2　adsorption　and　activation　in　N2　reduction　reaction　(NRR).　Regulating　the　catalyst　surface　electronic　state　is　treated　as　a　potential　strategy　to　prevail　over　the　barrier.　Here,　Incorporating　Fe　as　a　dopant　in　the　TiO2　nanoparticles　can　generate　oxygen　vacancies　and　dopant　energy　levels,　promoting　the　adsorption　and　activation　of　N2　molecules.　F　surface　modification　induces　Fe　(III)　in　the　high　spin　state　and　upshifts　the　dopant　energy　level.　That　facilitates　Fe　3d　electrons　backdonation　to　N　1ag*　orbital　promotes　the　activation　of　N2　molecule　and　reduces　the　limiting　potential　of　NRR.　Therefore,　F-Fe:　TiO2　electrocatalyst　achieved　the　highest　Faradaic　efficiency　and　maximum　NH3　production　rate　of　27.67%　and　27.86　mu　g　h-1　mgcat.　-1　at　-0.5　V　v.s.　reversible　hydrogen　electrode.　This　work　provides　deep　insights　into　the　design　surface　electronic　state　of　catalyst　toward　efficient　N2　to　NH3　conversion.