Facile Synthesis of Self-Supported Amorphous Phosphorus doped Ni(OH)2 Composite Anodes for Efficient Water Oxidation

Abstract

Water oxidation plays a pivotal role in energy conversion and storage such as water splitting and metal-air battery. The development of highly active and stable electrode for water oxidation at a low price is greatly challenging. Here we report a self-supported oxygen evolution reaction (OER) electrode with 3D porous Ni foam (NF) as a core and a dense layer of amorphous phosphorus doped Ni hydroxide (Ni-OH/P) film as the shell. This facile fabricated 3D core-shell structured electrode with directly grown active materials offers improved activity and prolonged stability for OER. It requires an overpotential of 490 mV to deliver the current density of 100 mA cm-2, shows a small Tafel slope at 87 mV dec-1, and sustains elongated electrolysis at 100 mA cm-2 for 100 h. The NiOOH shell is in-situ formed on the superficies of Ni-OH/P film. Then, a new core-shell structured film is constructed. The synergetic effects of the newly formed crystalline NiOOH shell and amorphous Ni-OH/P core contribute to its high stability under harsh conditions. This work presents a facile and easy scale-up path to develop self-supported hybrid electrodes for efficient and stable energy conversion and storage.