A New Member of Electrocatalysts Based on Nickel Metaphosphate Nanocrystals for Efficient Water Oxidation

Abstract

High-performance electrocatalysts are desired for electrochemical energy conversion, especially in the field of water splitting. Here, a new member of phosphate electrocatalysts, nickel metaphosphate (Ni P O ) nanocrystals, is reported, exhibiting low overpotential of 270 mV to generate the current density of 10 mA cm and a superior catalytic durability of 100 h. It is worth noting that Ni P O electrocatalyst has remarkable oxygen evolution performance operating in basic media. Further experimental and theoretical analyses demonstrate that N dopant boosts the catalytic performance of Ni P O due to optimizing the surface electronic structure for better charge transfer and decreasing the adsorption energy for the oxygenic intermediates.

Amorphous Cobalt Iron Borate Grown on Carbon Paper as a Precatalyst for Water Oxidation

“…Co 0.75 Fe 0.25 BO/CP displays a low overpotential of 227 mV at a current density of 10 mA cm −2 , which is distinctly smaller than that of CoBO/CP (290 mV) and IrO 2 /CP (297 mV) at the same current density. Impressively, Co 0.75 Fe 0.25 BO/CP shows the lowest overpotential at 10 mA cm −2 in alkaline medium, which surpasses the majority of metal boride and phosphate‐based electrocatalysts reported, for example, Fe‐Co‐2.3Ni‐B, Ni 3 B, Co‐Bi NS/G, Co 2 B, Co‐B@CoO, NiFe:Pi, Ni 2 P 4 O 12 , CoPPi, MnCoOP, NiFe 16 , and Ni 2 P 5 /Ni 3 (PO 4 ) 2 , as shown in Figure c. The Tafel slope of Co 0.75 Fe 0.25 BO/CP is 43.2 mV dec −1 , which is notably smaller than that of CoBO/CP (57.3 mV dec −1 ) and IrO 2 /CP (87.5 mV dec −1 ), suggesting faster kinetics and a superior OER catalytic performance to other samples (Figure d). The excellent performance was also confirmed in terms of the electrochemically active surface area (ECSA), which was determined from the double‐layer capacitance ( C dl ) method in the potential range where no redox reaction occurs (Figure S9 in the Supporting Information).…”

Modulierung der elektronischen Strukturen anorganischer Nanomaterialien für eine effiziente elektrokatalytische Wasserspaltung

“…[61][62][63][64] Die Einführung von Heteroatomen oder Radikalen kann die Periodizitätdes Gitters zerstçren und generiert so eine lokal veränderte elektronische Struktur. [61][62][63][64] Die Einführung von Heteroatomen oder Radikalen kann die Periodizitätdes Gitters zerstçren und generiert so eine lokal veränderte elektronische Struktur.…”

“…[61,64] Die Gruppe von Xie berichtete,d ass O-Dotanden die HER-Leistungsfähigkeit von 2H-MoS 2 -Nanoschichten enorm verbesserten, [64] wobei die dotierenden O-Atome unerwartet die Ladungsdichten in den Leitungsbändern wie auch Va lenzbändern gegenüber der Situation im reinen 2H-MoS 2 umverteilten. [61,64] Die Gruppe von Xie berichtete,d ass O-Dotanden die HER-Leistungsfähigkeit von 2H-MoS 2 -Nanoschichten enorm verbesserten, [64] wobei die dotierenden O-Atome unerwartet die Ladungsdichten in den Leitungsbändern wie auch Va lenzbändern gegenüber der Situation im reinen 2H-MoS 2 umverteilten.…”

Efficient Electrocatalytic Oxygen Evolution at Extremely High Current Density over 3D Ultrasmall Zero‐Valent Iron‐Coupled Nickel Sulfide Nanosheets

“…Numerous efforts have been devoted to develop low cost and highly efficient OER electrocatalysts, including transition metal nitrides,, phosphides, phosphates, oxides,, hydroxides,, oxyhydroxides,, and dichalcogenides . Among these transition metal compound electrocatalysts, nickel sulfides (Ni 3 S 2 , NiS 2 , α‐NiS, and β‐NiS) are considered among the most promising candidates as OER electrocatalysts for water electrolysis in alkaline media because of their good catalytic activity and natural abundance …”