A telluride-spinel ZnCo2Te4/NF catalyst delivered an overpotential (η) of only 370 mV to achieve a current density of 100 mA cm−2 and displayed no significant degradation of performance during 50 h of operation. By virtue of in situ synchrotron infrared spectroscopic detection, an accumulation of key OOH* intermediates over the active site was observed, suggesting that the reaction followed the efficient adsorbate evolution mechanism (AEM) for water oxidation.