Three-dimensional self-supporting catalyst with NiFe alloy/oxyhydroxide supported on high-surface cobalt hydroxide nanosheet array for overall water splitting

摘要

The development of available dual-function electrocatalysts is of great significance to the effective storage of excess electricity. Here, we obtained a three-dimensional Co(OH)(2) nanosheet with high surface area on nickel foam (Co(OH)(2)/NF) via conventional hydrothermal. NiFe-coated Co(OH)(2) nanosheet array (NiFe@Co(OH)(2) NSAs/NF) was further constructed by electrodeposition for water splitting. By optimizing and regulating the deposition time, NiFe@Co(OH)(2) NSAs/NF with a deposition time of 500 s (NiFe-500@Co(OH)(2) NSAs/NF) only needs 98 mV of overpotential and can be stabilized for 100 h for hydrogen evolution at 10 mA cm(-2) due to the rich density active components for NiFe alloy/oxyhydroxide layer and interaction with Co(OH)(2) nanosheets. Thanks to the excellent 3D nanosheet array structure and the close integration between Co (OH)(2) and the upper layer NiFe, NiFe@Co(OH)(2) NSAs/NF with a deposition time of 200 s (NiFe-200@Co (OH)(2) NSAs/NF) can provide 10 mA cm(-2) with only 204 mV and maintain constant catalysis within 100 h. Therefore, the constructed NiFe@Co(OH)(2) NSAs/NF (500 parallel to 200) double-electrode cell for water splitting requires only 1.58 V drive potential and can maintain 24 h durability at 10 mA cm(-2). The design of the catalyst opens up new ideas for the large-scale application of transition metals in water splitting. (C) 2021 Elsevier Inc. All rights reserved.