Onion-like carbon as dopant/modification-free electrocatalyst for [VO]2+/[VO2]+ redox reaction:Performance-control mechanism

Abstract

We investigate the application of the onion-like carbon (OLC) as an electrocatalyst for [VO]2þ/[VO2]þ redox flow reaction

its performance (electrocatalytic activity and reversibility) strongly increases with the synthesis to peak at 1800 C in 1000e2000 C range. The dopant/modification-free, optimized redox performances of the OLC is comparable to some of the best data in the literature of various types of carbon materials with post-synthesis modifications or doping. Mechanism behind such performance optimization is investigated employing various physical/electrochemical analyses as well as the firstprinciples calculations. We demonstrate that the carbon dangling bonds or the crystalline defects, generated by an inherent mechanism unique to the OLC, played a pivotal role in determining the electrocatalytic performances.