Nickel and manganese oxide heterostructure nanoparticles supported by carbon nanotube for highly efficient oxygen evolution reaction catalysis.

The OER performance of Ni/CNT composite can be greatly improved by introducing nano-scale heterostructure Ni x |Mn 1-x O particles on CNT surface. [Display omitted] • The heterostructure Nix|Mn1-xO nano-particles are stably anchored on CNT surface. • Ni 0.95 |Mn 0.05 O/CNT catalyst showed over potential of 293 mV and a low Tafel slope of 55.6mv dec-1. • DFT calculation revealed that the heterogeneous interface can enhance the absorption process of ·OH and ·O. Heterostructures have been shown to play a key role in promoting electrocatalysis. However, it is still a challenge to design and prepare multi metals heterostructure catalyst with high performance. In this paper, a simple and efficient preparation method was used to anchor Ni x |Mn 1-x O heterostructure nanoparticles on CNTs with oxygen defect sites. The treated CNT were used to provide stable anchor sites for metal ions, and effectively induced the production of highly fused Ni x |Mn 1-x O nanoparticles with atomic-level heterogeneous interfaces. The Ni 0.95 |Mn 0.05 O/CNT catalyst shows a nice oxygen evolution reaction performance. At a current density of 10 mA cm−2, the overpotential is only 293 mV, and the Tafel slope is 55.6 mV dec-1, which is much better than that of Ni/CNT and MnO/CNT catalyst under the same conditions. According to the experimental result and density functional theory calculation, it is suggested that the proportion of heterogeneous metal elements, the phase composition at the heterogeneous interface, the heterostructure size and the heterostructure carrier will affect the oxygen evolution catalyst performance. This work is benefit for the design of cheap and high-performance catalyst with multi metal heterogeneous interfaces. [ABSTRACT FROM AUTHOR]