MnCo2O4 decorating porous PbO2 composite with enhanced activity and durability for acidic water oxidation

Abstract

Developing a promising catalyst with both improved activity and robust durability for the oxygen evolution (OER) in an acidic electrolyte is extremely desirable. Here we constructed a novel MnCo2O4 decorating PbO2 electrode (3D-Ti/α-PbO2/β-PbO2-MnCo2O4) with a sandwich-like structure via a successive co-precipitation and co-electrodeposition onto porous titanium (3D-Ti) support. The experimental results indicated that the introduction of porous titanium is essential for achieving a unique porous structure architecture. In addition, the adoption of MnCo2O4 increased the contact area with electrolyte due to the large BET surface area of 144.06 cm2 g−1. Consequently, the synthesized 3D-Ti/α-PbO2/β-PbO2-MnCo2O4 composite electrode exhibited a low overpotential of 379 and 453 mV at 10 and 50 mA cm−2, respectively, as well as a minor Tafel slope of 133 mV per decade in 0.5 M H2SO4 solution. Furthermore, 3D-Ti/α-PbO2/β-PbO2-MnCo2O4 presents robust durability, keeping steady for more than 140 h at 50 mA cm−2 and without observable performance degradation, which is superior to many reported state-of-the-art non-precious OER catalysts. This route is for creating and synthesizing non-precious and superior performance catalysts for electrolysis and beyond.