Peripherally and non-peripherally carboxylic acid substituted Cu(II) phthalocyanine/reduced graphene oxide nanohybrids for hydrogen evolution reaction catalysts
Ekrem Kaplan, Tolga Karazehir, Selin Gümrükçü, Baran Sarac, A. Sezai Sarac and Esin Hamuryudan*
This work, which is supported by the Research Fund of the Istanbul Technical University (Project Number: 42019), has been achieved in the research laboratory of Prof. Dr. Esin Hamuryudan and published in the Molecular Systems Design & Engineering. In this study, it is reported that nanohybrid electrocatalyst materials based on peripherally and non-peripherally carboxylic acid substituted copper phthalocyanines (CuPcs) and reduced graphene oxide (rGO) constructed via π–π interactions between CuPcs and rGO. Prepared nanocomposites were coated onto the surface of a glassy carbon electrode and their electrocatalytic activity for the hydrogen evolution reaction (HER) was studied. Structural, electrochemical, and surface morphological properties of the produced electrodes were investigated. Electrochemical measurements indicated that the peripherally substituted rGO/CuPc electrodes have more efficiency and activity compared to the non-peripherally substituted ones. In addition, the EIS results show that peripherally carboxylic substituted rGO/CuPc electrodes become more conductive due to the position and content of the carboxyl groups. This increasing performance of the HER implied by a smaller impedance together with more facile electron transfer kinetics indicates a pronounced enhancement of the electrocatalytic hydrogen activity of peripherally carboxylic substituted rGO/CuPc electrodes.