2 ) and Co-LDH (414 mV at -0.5 mA/cmECSA 2 and 378 mV at -10 mA/cm geo. 2 ). The observed overpotential difference between L-CoS and oxide/hydroxide-based references at pH with ca. 32 mV is much smaller compared to that at pH 0 with ca. 315 mV (Figure and Figure ).