کلیدواژهها
|
Water oxidation, Electrochemistry, Electrocatalyst, MnII salophen complexes, Mn oxide
nanostructures
|
چکیده
|
Developing robust and efficient water oxidation catalysts is an essential challenge in water
splitting. In this work, the electrocatalytic behavior of the modified carbon paste electrodes with
different substituted MnII salophen complexes, MnL1
-MnL3
, (H2L1= N,N-bis(salicylidene)-1,2-
diaminobenzene, H2L2=N,N-bis(salicylidene)-4-bromo-1,2-diaminobenzene and H2L3= N,N-
bis(2-hydroxy-3-methoxybenzilidine)-1,2-diaminobenzene) was evaluated for water oxidation by
electrochemical methods. All three complexes were found highly effective, stable, and robust
catalysts for water oxidation. Electrochemical experiments, Field emission-scanning electron
microscope (SEM), energy-dispersive X-ray (EDX), and powder X-ray diffraction (PXRD)
analyses indicated that the studied MnII salophen complexes are molecular catalysts for water
oxidation in origin. Cyclic voltammetry experiments in different pHs displayed that the O-O bond
formation probably occurs by oxidizing the active center of MnII complexes through proton-
2
coupled electron transfer (PCET). The results showed that the nature of the substituent on the
salophen ligand could not affect the stability of the complexes under applied electrochemical
conditions. It was found that Mn oxide nanostructures obtained by the thermal decomposition of
MnL1
can also effectively catalyze the reaction, but in comparison with MnL1
, they have lower
activity
|