A molecular approach to self-supported cobalt-substituted ZnO materials as remarkably stable electrocatalysts for water oxidation.
In regard to earth-abundant cobalt water oxidation catalysts, very recent findings show the reorganization of the materials to amorphous active phases under catalytic conditions. To further understand this concept, a unique cobalt-substituted crystalline zinc oxide (Co:ZnO) precatalyst has been synthesized by low-temperature solvolysis of molecular heterobimetallic Co(4-x)Zn(x) O4 (x = 1-3) precursors in benzylamine. Its electrophoretic deposition onto fluorinated tin oxide electrodes leads after oxidative conditioning to an amorphous self-supported water-oxidation electrocatalyst, which was observed by HR-TEM on FIB lamellas of the EPD layers. The Co-rich hydroxide-oxidic electrocatalyst performs at very low overpotentials (512 mV at pH 7; 330 mV at pH 12), while chronoamperometry shows a stable catalytic current over several hours.
Department of Chemistry, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin (Germany).
Johannes
J
Pfrommer
Michael
M
Lublow
Anahita
A
Azarpira
Caren
C
Göbel
Marcel
M
Lücke
Alexander
A
Steigert
Martin
M
Pogrzeba
Prashanth W
PW
Menezes
Anna
A
Fischer
Thomas
T
Schedel-Niedrig
Matthias
M
Driess
amorphous materials; electrocatalysis; heterogeneous catalysis; self-activation; water oxidation