▎ 摘　　要

Coatings, obtained by one step electrodeposition of self-assembled positively charged Co, Mn tetra(Nmethyl-4-pyridyl) porphyrin (CoP and MnP, respectively) or both metalloporphyrins with negatively charged carboxyl-rich graphene oxide, were characterized using microscopic (SEM, TEM, AFM), spectroscopic (UV-vis, Raman, XPS), and electrochemical (cyclic voltammetry, chronoamperometry, RRDE) methods. We show that coatings based on Co or Mn porphyrin on glassy carbon electrodes efficiently catalyze oxygen reduction in basic solutions by a main 2e-reduction to produce the H2O2 useful chemical. However, it is possible to convert the process into a 4e-reduction process by cobalt porphyrin-based coatings comprised also of controllable amounts of Mn porphyrin which acts as a H2O2 dismutation agent. Electrodes containing both metalloporphyrins (MnP/CoP =1.2) showed longer term stability during oxygen reduction at a potential of -0.35 V vs. Ag/AgCl in comparison to ones containing only cobalt porphyrin: turnover frequencies of 0.30 and 0.17 s(-1), respectively. The concept of integrating various multi-tasking non noble-based catalysts in electrodeposited graphene derivatives can be exploited for further development of practical devices able to produce chemicals or energy. (C) 2020 Published by Elsevier Ltd.