Metallic　MoS2　(i.e.,　1T-MoS2)　is　considered　as　the　most　promising　precious-metal-free　electrocatalyst　with　outstanding　hydrogen　evolution　reaction　(HER)　performance　in　acidic　media　comparable　to　Pt.　However,　sluggish　kinematics　of　HER　in　alkaline　media　and　its　inability　for　the　oxygen　evolution　reaction　(OER),　hamper　its　development　as　bifunctional　catalysts.　The　instability　of　1T-MoS2　further　impedes　its　applications　for　scaling　up,　calling　an　urgent　need　for　simple　synthesis　to　produce　stable　1T-MoS2.　In　this　work,　the　challenge　of　1T-MoS2　synthesis　is　first　addressed　using　a　direct　one-step　hydrothermal　method　by　adopting　ascorbic　acid.　1T-MoS2　with　flower-like　morphology　is　obtained,　and　transition　metals　(Ni,　Co,　Fe)　are　simultaneously　doped　into　1T-MoS2.　Ni-1T-MoS2　achieves　an　enhanced　bifunctional　catalytic　activity　for　both　HER　and　OER　in　alkaline　media,　where　the　key　role　of　Ni　doping　as　single　atom　is　proved　to　be　essential　for　boosting　HER/OER　activity.　Finally,　a　Ni-1T-MoS2||Ni-1T-MoS2　electrolyzer　is　fabricated,　reaching　a　current　density　of　10　mA　cm(-2)　at　an　applied　cell　voltage　of　only　1.54　V　for　overall　water　splitting.