Stoichiometry design in hierarchical CoNiFe phosphide for highly efficient water oxidation

Rational composition design of trimetallic phosphide catalysts is of significant importance for enhanced surface reaction and efficient catalytic performance. Herein, hierarchical Co _x Ni _y Fe _z P with precise control of stoichiometric metallic elements (x:y:z = (1-10):(1-10):1) has been synthesized, and Co_1.3Ni_0.5Fe_0.2P, as the most optimal composition, exhibits remarkable catalytic activity (η = 320 mV at 10 mA cm^-2) and long-term stability (ignorable decrease after 10 h continuous test at the current density of 10 mA cm^-2) toward oxygen evolution reaction (OER). It is found that the surface P in Co_1.3Ni_0.5Fe_0.2P was replaced by O under the OER process. The density function theory calculations before and after long-term stability tests suggest the clear increasing of the density of states near the Fermi level of Co_1.3Ni_0.5Fe_0.2P/Co_1.3Ni_0.5Fe_0.2O, which could enhance the OH^- adsorption of our electrocatalysts and the corresponding OER performance.

ELECTRONIC SUPPLEMENTARY MATERIAL

Supplementary material is available in the online version of this article at 10.1007/s40843-022-2061-x.

Low-temperature wet chemistry synthetic approaches towards ferrites

Solution chemistry allows the crystallisation of range of iron oxides, including MFe₂O₄ spinels, MFeO₃ perovskites and hexaferrites, such as BaFe₁₂O₁₉, with nanoscale crystallinity and properties suitable for fields such as catalysis and electronics.