Featherlike NiCoP Holey Nanoarrys for Efficient and Stable Seawater Splitting

Abstract

Developing earth-rich highly efficient nonprecious electrocatalysts for hydrogen evolution reaction (HER) has become of great significance for sustainable energy technology. Herein, novel nickel foam (NF) supported porous featherlike NiCoP (PF-NiCoP/NF) nanoarrys are constructed by a successive hydrothermal and phosphidation way. Simultaneously, their three-dimensional (3D) morphology, the holey structure, and the conductive substrate are favorable for the enhanced specific surface area, efficient electron and mass transfer, and exposure of more active sites, and also are beneficial for the release of generated H2. PF-NiCoP/NF demonstrates high activity and long-term durability in alkaline media (1 M KOH) and real seawater, reaching the current density of 10 mA cm–2 at overpotentials of 46 and 287 mV, respectively. Moreover, the faradaic efficiency of 3D PF-NiCoP/NF is as high as 96.5% in real seawater. As expected, PF-NiCoP/NF exhibits superior performance in comparison to those of most of HER electrocatalysts in real seawater and alkaline media. This work may present a new strategy to design a promising electrocatalyst superior to platinum in a wide range of pH and may provide a new idea for electrocatalytic seawater splitting.

A review of sodium chloride-based electrolytes and materials for electrochemical energy technology

“…Therefore, researchers have devoted a great deal of effort to the development of catalysts having high efficiency and excellent selectivity for hydrogen production by electrocatalysis, photocatalysis and photoelectrocatalysis of NaCl-based solutions. The electrocatalysts reported at present mainly include Pt-based materials, 26,[211][212][213][214][215][216][217][218] Ni-based materials, 23,[218][219][220][221] Mo-based materials, [222][223][224][225] doped carbon materials, 226 and so on. 184 TiO 2based materials 227,228 and Zn-based materials [229][230][231][232] as photocatalysts have broad application prospects.…”

Common-Ion Effect Triggered Highly Sustained Seawater Electrolysis with Additional NaCl Production

“…The preparation of ternary NiCoFe hydroxide array followed a previous report with some modifications [ 16 ]. In a typical synthesis, 3 mmol of Co(NO 3 ) 2 ·6H 2 O, 1 mmol Fe(NO 3 ) 3 ·2H 2 O, 15 mmol of urea, and 8 mmol of NH 4 F were dissolved in 45 mL of deionized water.…”

“…As a consequence, seawater splitting encounters challenges such as undesirable chlorine oxidation reaction [ 14 ] and severe corrosion of electrodes [ 8 , 15 ]. In contrast to the tremendous efforts devoted recently to develop highly active electrocatalysts (e.g., metal, metal phosphide [ 16 ], doped nanocarbons [ 17 ], and Ni-Fe-C [ 18 ] for hydrogen evolution and metal hydroxide [ 19 ], carbonate [ 14 ], and nitride [ 10 ] for oxygen evolution), few works focused on the electrolyte design so far. Indeed, contemporary works employed mimic seawater in alkaline electrolyte (e.g., 0.5 M NaCl +1 M KOH) as water source and reported attractive electrolysis performance [ 9 , 10 , 20 ].…”

CeO2 decorated bimetallic phosphide nanowire arrays for enhanced oxygen evolution reaction electrocatalysis via interface engineering

“…The development of efficient and durable electrocatalysts that can perform well at high current densities in seawater oxidation is significant. 72,73 Considering the outstanding OER activity of Co 0.4 Ni 1.6 P-CeO 2 /NF in the 1 M KOH electrolyte, the electrocatalytic performance of Co 0.4 Ni 1.6 P-CeO 2 /NF for the OER in simulated seawater was also studied. Since the dominant component of natural seawater is NaCl (0.5 M), and the lower standard potential of the OER compared to the chlorine evolution reaction (CER), it is recommended to adopt simulated alkaline seawater (1 M KOH + 0.5 M NaCl) for the basic study and better analysis of the reaction involved.…”