Water electrolysis, fuel cells, and metal-air batteries all require efficient and cheap electrocatalysts that can significantly lower the reaction overpotentials. Bimetallic alloys and their oxides or nitrides compounds are particularly interesting as non-precious metal electrocatalyst materials for HER and OER, because of their tailorable electronic structure, conductivity, and surface chemistry. Our group has been actively working on nanoarray materials directly grown on conductive substrates as electrodes for supercapacitor, batteries and electrocatalyst.

In this talk, I will present two main results about surface and interface engineering/functionalization of array-type electrocatalysts for water splitting and for meal-ion batteries.

(1) RF nitrogen and carbon plasma as a highly effective technique for conversion reaction and surface functionalization of nanostructured electrocatalysts. The N plasma treatment not only generates hierarchical nanostructure surface, but also induces N doping as well as hydrophilicity. Using C-plasma, we can partially reduce the metal oxide surface, and simultaneously deposit a thin and uniform carbon coating.

(2) We demonstrate that dual cation doping, or cation-anion co-doping can simultaneously modulate key parameters in water dissociation and hydrogen adsorption energies. As a result, the dopings lead to a significant enhancement in catalytic activities for both HER and OER. Recent result on atomic scale doping in 2D materials will also be presented.

(3) I will also present our achievements of effective bi-functional catalysts (ORR and OER) for cathode materials in Li-O2 and Zn air batteries.