Introducing amorphous and ultrathin nanosheets of transition bimetal phosphate arrays that are highly active in the oxygen evolution reaction (OER) as shells over an electronically modulated crystalline core with low hydrogen absorption energy for an excellent hydrogen evolution reaction (HER) can boost the sluggish kinetics of the OER and HER in alkaline electrolytes. Therefore, in this study, ultrathin and amorphous cobalt‐nickel‐phosphate (CoNiPO
x
) nanosheet arrays are deposited over vanadium (V)‐doped cobalt‐nitride (V
3%
‐Co
4
N) crystalline core nanowires to obtain amorphous‐shell@crystalline‐core mesoporous 3D‐heterostructures (CoNiPO
x
@V‐Co
4
N/NF) as bifunctional electrocatalysts. The optimized electrocatalyst shows extremely low HER and OER overpotentials of 53 and 270 mV at 10 mA cm
−2
, respectively. The CoNiPO
x
@V
3%
‐Co
4
N/NF (+/−) electrolyzer utilizing the electrocatalyst as both anode and cathode demonstrates remarkable overall water‐splitting activity, requiring a cell potential of only 1.52 V at 10 mA cm
−2
, 30 mV lower than that of the RuO
2
/NF (+)/20%‐Pt/C/NF (−) electrolyzer. Such impressive bifunctional activities can be attributed to abundant active sites, adjusted electronic structure, lower charge‐transfer resistance, enhanced electrochemically active surface area (ECSA), and surface‐ and volume‐confined electrocatalysis resulting from the synergistic effects of the crystalline V
3%
‐Co
4
N core and amorphous CoNiPO
x
shells boosting water splitting in alkaline media.
Density functional theory simulations demonstrate that single and triple Ta-atom catalysts anchored to C2N monolayer act as superior catalysts for the nitrogen reduction reaction via alternating and distal pathways.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.