Solution Plasma‐Assisted Multivariate Metal Nanoalloys Encapsulated with Carbon Dots for Efficient Oxygen Evolution Reaction

Abstract

AbstractTo accelerate the reaction kinetics of electrocatalytic oxygen evolution reaction (OER), a multicomponent CDs@(PdFeNiCo)Nbx nanohybrid comprising multiple metal nanoalloys and carbon quantum dots (CDs) was in situ generated by treating the mixture of Nb2C quantum dots (Nb2C QDs) and a variety of metal ions (M2+=Pd2+, Fe2+, Co2+, Ni2+) through the solution plasma (SP) modification technique. The CDs@(PdFeNiCo)Nbx catalyst was further explored as an electrocatalyst for OER in alkaline solution. Under nitrogen plasma irradiation with high input power (200 W), diverse bimetallic nanoalloy particles, including NbPd3, FeNb, NbNi3, and CoNbO4 nanoalloys, were generated, accompanied with the decomposition of Nb2C QDs into CDs. In view of the synergic effect between multivariate metal active sites and highly conjugated CD network, the developed CDs@(PdFeNiCo)Nbx electrocatalyst showed a small overpotential of 240 mV for achieving the current density of 10 mA cm−2, together with a very low Tafel slope of 62 mV dec−1, which substantially outperformed those of the state‐of‐the‐art metal electrocatalysts and was competitive with most metal oxides. The CDs@(PdFeNiCo)Nbx electrocatalyst also showed a negligible overpotential change during 30 h chronopotentiometry measurement. The present work can provide a feasible alternative strategy for the development of an excellent OER electrocatalyst using the SP modification method.