Abstract
Layered double hydroxides (LDH) are being used as electrocatalysts for oxygen evolution reactions (OERs). However, low current densities limit their practical applications. Herein, we report a facile and economic synthesis of an iron-copper based LDH integrated with a cobalt-based metal-organic framework (ZIF-12) to form LDH-ZIF-12 composite (1) through a co-precipitation method. The as-synthesized composite 1 requires a low overpotential of 337 mV to achieve a catalytic current density of 10 mA cm(-2) with a Tafel slope of 89 mV dec(-1). Tafel analysis further demonstrates that 1 exhibits a slope of 89 mV dec(-1) which is much lower than the slope of 284 mV dec(-1) for LDH and 172 mV dec(-1) for ZIF-12. The slope value of 1 is also lower than previously reported electrocatalysts, including Ni-Co LDH (113 mV dec(-1)) and Zn-Co LDH nanosheets (101 mV dec(-1)), under similar conditions. Controlled potential electrolysis and stability test experiments show the potential application of 1 as a heterogeneous electrocatalyst for water oxidation.