N-doped carbon nanotubes supported CoSe nanoparticles: A highly efficient and stable catalyst for HO electrosynthesis in acidic media.

Unlabelled: Electrocatalytic oxygen reduction reaction (ORR) provides an attractive alternative to anthraquinone process for HO synthesis. Rational design of earth-abundant electrocatalysts for HO synthesis via a two-electron ORR process in acids is attractive but still very challenging. In this work, we report that nitrogen-doped carbon nanotubes as a multi-functional support for CoSe nanoparticles not only keep CoSe nanoparticles well dispersed but alter the crystal structure, which in turn improves the overall catalytic behaviors and thereby renders high O-to-HO conversion efficiency. In 0.1 M HClO, such CoSe@NCNTs hybrid delivers a high HO selectivity of 93.2% and a large HO yield rate of 172 ppm·h with excellent durability up to 24 h. Moreover, CoSe@NCNTs performs effectively for organic dye degradation via electro-Fenton process.

Electronic Supplementary Material: Supplementary material (SEM images, EDX mapping images, XPS spectrum, XRD patterns, RRDE voltammogram, Tafel plots, cyclic voltammograms, UV-Vis spectra, and Tables S1) is available in the online version of this article at 10.1007/s12274-021-3474-0.