A pH-mediated enhancement of the graphene carbocatalyst activity for the reduction of 4-nitrophenol.

Using alkaline pH adjustment, the reaction between graphene oxide and L-ascorbic acid led to the formation of a carbocatalyst film with numerous graphene edges protruding out of basal planes, which had a markedly enhanced carbocatalytic activity for conversion of 4-nitrophenol to 4-aminophenol, as compared to that of the carbocatalyst counterpart without involving pH mediation.