“…Ir-ZIF-67@CoFe PBA(5 h) possessed a smaller Tafel slope of 80.1 mV·dec –1 , while the Tafel slopes of ZIF-67@CoFe PBA, Ir-CoFe PBA, Ir-ZIF-67, and Ir-ZIF-67@CoFe PBA(10 h) were 134.15, 104.1, 110.5, and 98.3 mV·dec –1 , demonstrating a faster reaction kinetics of Ir-ZIF-67@CoFe PBA(5 h) for OER. More importantly, as shown in Figure d, Ir-ZIF-67@CoFe PBA is not inferior to Ir-doped catalysts reported in recent years. − The OER activity of Ir-ZIF-67@CoFe PBA hollow nanoboxes is comparable to that of recently reported electrocatalysts, showing great promise for future application toward water splitting. − …”