Efficient Oxygen Evolution Reaction (OER) is yet a demanding task for practical water splitting. Compared with powdery OER electrocatalysts, binder-free catalyst films directly deposited on conductive substrates are intriguing with respects to more exposed active sites and higher tolerance to violent gas bubbling. Xinxin Liang recently prepared a binder-free film composed of nickel ferrite by anodic oxidation of nickel alloy in molten salt (MS). Merits of the electrochemical oxidation in molten salts are highlighted by generation of spinel NiFe2O4 film over Ni-Fe-Cu substrate with full exposure of OER-active Fe species, absence of OER-inert CuO species and good adhesion with the substrate. The prepared film electrode therefore possesses a higher electrocatalytic activity than that of the commercial IrO2/Ta2O5-Ti electrode towards OER in alkaline electrolyte.

The present study highlights the potential on utilization of electrochemical oxidation of metallic substrates in molten salts for fast preparation of high-quality oxide films with promising functionality. The above results are now accepted for publication in Journal of Materials Chemistry A as a Hot Paper (2019, DOI: 10.1039/C9TA00997C).

Author: professor Xiao