Preparation method and application of carbon-loaded NiO/NiFe2O4 spinel type solid solution electrolysis water oxygen evolution catalyst

Abstract

The invention discloses a preparation method and application of a carbon-loaded NiO/NiFe2O4 spinel type solid solution electrolysis water oxygen evolution catalyst. The preparation method comprises the following steps: preparing flower-ball-shaped nickel/iron bimetal hydroxide (NiFe-LDH) through a hydrothermal reaction, stripping nanosheets through high-speed shearing and a cavitation effect of ultrasonic waves, then assembling the product with single-layer graphene oxide (GO), and performing reducing to obtain LDH-rGO; fully impregnating the LDH-rGO in low-concentration Fe (OH)3 colloid, introducing iron ions to the surface of the LDH-rGO, so that more catalytic active sites are formed; after high-temperature calcination, forming the rGO-loaded spinel type NiO/NiFe2O4 heterogeneous composite catalyst, NiO mainly existing in NiFe2O4 crystal lattices in a solid solution form. The prepared composite nano oxygen evolution electrocatalyst is large in specific surface area, has abundant catalytic active sites, and also has good conductivity. Compared with commercial RuO2, the oxygen evolution catalyst has the advantages of low cost, high catalytic activity, good stability and the like, and has wide utilization value in alkaline water electrolysis.

Description

technical field [0001] The invention belongs to the field of new energy material technology and electrochemical catalysis, and in particular relates to a rGO loaded NiO / NiFe 2 o 4 A spinel-type solid solution electrolysis oxygen evolution catalyst material and a preparation method thereof. Background technique [0002] At present, the vast majority of hydrogen production still relies on reactions involving fossil energy such as natural gas reforming. Hydrogen production by water electrolysis provides a zero-carbon hydrogen production method. It only needs to provide electricity and water to easily obtain hydrogen energy. . Alkaline water electrolysis is currently the most mature electrolytic water hydrogen production technology, and the efficiency of water splitting hydrogen production is mainly restricted by the slow kinetic process of oxygen evolution reaction. At present, the main precious metal catalysts on the market are RuO 2 , IrO 2 , while their scarcity and high...

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Problems solved by technology

For example, Chinese patent CN111420663 A invented a copper-aluminum spinel solid solution structure, but copper-aluminum metal oxides are not as active as nickel-iron in the oxygen evolution reaction, and the OER overpotential still needs to be further reduced

Studies have shown that layered double metal hydroxides have excellent OER performance. For example, Chinese patent CN111686736A discloses a preparation method of NiFe LDH / NF electrolytic water catalyst containing highly active and high-valence iron, which has excellent catalytic performance, but its The stability is not as good as spinel, which is not conducive to industrial applications. If spinel can be directly obtained by calcining LDH, higher performance may be obtained

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