In　promising　transition　metal　sulfide　catalysts,　the　extraordinary　instability　under　air　exposure　and　oxygen　evolution　reaction　(OER)　catalysis　severely　degrades　their　activity　and　stability　in　the　electrochemical　water　splitting　reaction,　inhibiting　their　practical　applications.　Herein,　guided　by　a　theoretical　mechanism　study,　it　is　disclosed　that　the　adsorbing　ability　and　electronic　interaction　for　molecular　oxygen　will　be　significantly　weakened　in　nickel　disulfide　(NiS2)　by　constructing　an　electron-deficient　distribution　on　Ni-S　sites　with　N　atom　introduction,　which　efficiently　inhibits　the　process　of　O2adsorption　and　electrophilic　activation　during　oxidation,　thus　achieving　air-stable　capacity　for　NiS2.　In　addition,　theoretical　calculations　further　reveal　that　such　an　electronic　redistribution　will　weaken　the　OH-adsorption　on　NiS2and　thus　inhibit　the　reconstruction　process　during　the　OER　process.　Inspired　by　this,　NiS2nanosheets　(NiS2NSs)　are　synthesized　and　N　atoms　are　introduced　to　bridge　with　Ni　and　S,　resulting　in　electron-deficient　Ni　and　S　sites　in　N　atom-bridged　NiS2NSs　(N-NiS2NSs).　As　expected,　only　28.1%　of　the　NiS2phase　is　oxidized　into　sulfate　nickel　in　N-NiS2NSs　after　one　month　of　air　exposure　with　only　13　mV　overpotential　degradation　toward　the　OER,　while　for　NiS2NSs,　a　fast　and　drastic　phase　transformation　is　undergone,　resulting　in　155　mV　OER　decline.　For　the　OER　process,　the　reconstruction　from　sulfides　to　(oxy)hydroxides　is　deservedly　inhibited　in　such　N-NiS2NSs,　with　an　in　situ　constructed　N-NiS2/NiOOH　heterostructure　as　an　OER　active　phase,　which　exhibits　higher　OER　activity　and　stability　compared　to　those　of　completely　NiOOH-oxidized　NiS2NSs.　Rationalized　by　density　functional　theory　(DFT)　calculations,　the　N-NiS2/NiOOH　heterostructure　features　a　strong　electron　rearrangement　at　the　interface,　thus　improving　the　chemisorption　ability　and　conductivity　compared　to　those　of　pristine　NiOOH.　Moreover,　such　a　strategy　of　improving　the　air　stability　is　also　valid　for　other　transition　metal　sulfides　(TMS)　(such　as　CoS2and　FeS2).　©　2022　American　Chemical　Society.　All　rights　reserved.