Three-Dimensional Amorphous Cobalt Phosphate Nanosheets for Efficient Overall Water Splitting in Neutral Electrolytes

at a low cell voltage of 1.97 V. The electrode also demonstrates exceptional sustained stability, retaining the target current density with only 1.5% voltage augmentation over 80 h of uninterrupted operation. The remarkable performance stems from the distinctive architecture featuring vertically interconnected amorphous nanosheet arrays grown directly on Co foam, which ensures efficient interfacial electron transfer. The amorphous nature provides a high density of active sites and enhanced carrier density, as confirmed by Mott-Schottky analysis, while three-dimensional architecture facilitates mass transport and promotes bubble detachment. These integrated features collectively contribute to the superior catalytic kinetics. This study offers an economical and controllable synthesis route for designing nanoarray electrodes with superior HER and OER performance, thereby providing a promising strategy toward efficient and economically viable neutral overall water splitting.