Colloid self-assembly of c-axis oriented hydroxide thin films to boost the electrocatalytic oxidation reaction.

[Display omitted] • C -oriented NiFe-LDH films were fabricated by colloid self-assembly method. • NiFe-LDH-F shows superior OER performance with an low overpotential. • The self-assembly stacking film shows high proton diffusion coefficient. • Ni(OH) 2 -F shows excellent ethanol electrooxidation reaction performance. Uniform close-packed superlattice self-assembled from colloidal nanocrystals usually exhibit different chemical and physical properties compared with the homologous bulk materials. Herein, c -oriented NiFe-LDH films (NiFe-LDH-F) and Ni(OH) 2 films (Ni(OH) 2 -F) were successfully fabricated by a colloid self-assembly method. The electrocatalytic oxidation properties of the resulting c -oriented NiFe-LDH-F and Ni(OH) 2 -F were studied towards the oxygen evolution reaction (OER) and the ethanol electrooxidation reaction (EOR), respectively. Due to orderly stacking c -oriented superlattices, the NiFe-LDH-F and Ni(OH) 2 -F both showed high proton diffusion coefficients, which significantly improved the electrocatalytic activities. The NiFe-LDH-F on the glassy carbon electrode showed an excellent OER electrocatalytic activity with a small overpotential of 220 mV at 10 mA cm−2 and a low Tafel slope of 53.3 mV dec−1. The Ni(OH) 2 -F showed a superior EOR performance without obvious passivation. This study may open up a new insight into designing efficient and robust materials for superior electrocatalysis.. [ABSTRACT FROM AUTHOR]