In situ growth of porphyrinic metal-organic framework nanocrystals on graphene nanoribbons for the electrocatalytic oxidation of nitrite

Graphene nanoribbons (GNRs) are incorporated with the nanocrystals of a porphyrinic metal-organic framework, MOF-525, by solvothermally growing MOF-525 in a suspension of well-dispersed GNRs. A nanocomposite, which is composed of the MOF-525 nanocrystals interconnected by numerous one-dimensional GNRs, is successfully synthesized. Due to the excellent dispersity, uniform thin films of the MOF-525/GNR nanocomposite can be simply deposited on conducting glass substrates by using drop casting. The obtained thin film of the MOF-525/GNR nanocomposite is applied for electrochemical nitrite sensors. The MOF-525 nanocrystals serve as a high-surface-area electrocatalyst toward nitrite and the interconnected GNRs act as conductive bridges to provide facile charge transport. The thin film of the MOF-525/GNR nanocomposite thus exhibits a much better electrocatalytic activity for the oxidation of nitrite compared to the pristine MOF-525 thin film.