Zn_1.2Co_1.8O_3.5 performance in 1 M KOH: Tafel slope and overpotentials (η) at 298 K on different substrates as compared to NiFe hydroxides under similar conditions.

Anode stack	Tafel slope/mV dec−1	η/V	Loadb/μg cm−2	TOFa/s−1	Ref.
Spinel/Ti-mesh	40.5	0.35	90	0.07	This work
Spinel/Au–Ti-mesh	48.5	0.4	90	0.02	This work
Spinel/Al:ZnO	42.2	0.43	180	<0.01	This work
NiFe-LDHc/GCd	67	0.347	70	0.01	10
3D-NiFe-LDH/Ni	50	0.250	1000	0.028	9
Ni–Fe/Au	58	0.331	140	—	36

^aAt η = 0.35 V.

^bElectrocatalyst load mass.

^cLayered double hydroxide.

^dGlassy carbon.