Direct Fabrication of Nanoscale NiVO _xElectrocatalysts over Nickel Foam for a High-Performance Oxygen Evolution Reaction

The pursuit of competent water oxidation catalysts operating at a low onset overpotential (<1.50 V vs RHE), achieving high current densities (>1000 mA/cm2) over a narrow potential range, and showing tremendous durability is a growing hot issue and remains a grand challenge. In this study, high-activity water oxidation is shown over noble-metal-free, bimetallic nickel vanadium oxide (NiVOx) thin-film electrocatalysts developed over three-dimensional nickel foam (NF) via the single-step aerosol-assisted chemical vapor (AACVD) technique under controlled conditions. Distinct morphological transformations from a micro-nano to a nanoscale catalytic structure are observed by simply increasing the deposition time from 60 to 180 min. The catalyst prepared for 180 min (NiVOx/NF180) initiates the OER at a mere potential of 1.42 V vs RHE and exhibits current decade at 1.44 V vs RHE, peak current density >1200 mA/cm2 at just 1.64 V vs RHE, a low Tafel slope of 60 mV/dec, and remarkable stability during a prolonged period of water oxidation catalysis. The catalytic activity is comparable to and even better than state-of-the-art Ru-based catalysts investigated in alkaline conditions. The high activity can be ascribed to the subtly modulated local coordination environment and electronic structure of the Ni/V compound in the nanotextured catalyst. This work provides a competent, efficient, and high-efficiency anodic oxygen evolution and chemical energy conversion catalyst that is easily accessible via a straightforward AACVD route while employing simple precursors.