Crystal interpenetration featured NiWSe@NF acicular nanowires for performance enhanced water splitting.

Synergistic composite catalysts have always been the research focus of water splitting. Whereas, amorphous phases usually occurred on grain boundaries, which greatly hinders electron transfer and reduces the catalytic performance. Herein, a NiWSe@NF acicular nanowire electrode was fabricated by a simple hydrothermal strategy, affording outstanding activity and durability, requiring overpotentials of only 103 mV (HER) and 203 mV (OER) under 10 mA cm−2, respectively. Experimental studies and theoretical analysis demonstrate that the excellent catalytic activity is attributed to the interpenetrate structure, which eliminates the formation of amorphous phase and provides a high-speed channel for electron transmission. The crystal interpenetration on grain boundaries adjusts the electronic, promotes the intermediates adsorption and reduce reaction energy barrier. The super-hydrophilic arisen from crystal interpenetration would also reduce the adhesion of generated bubbles and avoid performance attenuation. This work provides a new perspective for the development of high-efficiency composite catalysts. NiWSe@NF electrode with crystal interpenetrating structure eliminates the amorphous phase between interfaces, effectively adjusts the electronic distribution of heterostructure, and achieve ultra-low overpotential bifunctional catalytic activity of HER and OER. [Display omitted] • Neoteric crystal interpenetration featured NiWSe@NF electrode has been prepared. • The NiWSe@NF acicular nanowires electrode shows super-hydrophilic ability. • Crystal interpenetrating structure promotes the intermediates adsorption and reduce reaction energy barrier. • The current density of 10 mA cm−2 can be reached by only 1.53 V of the overall water splitting. • The NiWSe@NF electrode exhibits excellent catalytic stability. [ABSTRACT FROM AUTHOR]