No abstract

No abstract

The oxygen evolution reaction (OER) is considered the rate-limiting step in electrochemical water splitting, and has been widely used to solve energy and environmental issues. Perovskite oxides (ABO3) exhibit good OER activity, owing to their tunable electronic structures and highly flexible elemental compositions. However, the preparation of perovskite oxides usually requires long exposure to high temperatures, resulting in metal agglomeration and undesirable effects on intrinsic activity. Vapor-phase microwave technology can significantly reduce the duration of heat treatment and subsequently reduce the associated carbon emissions. This technology not only addresses the growing demand for carbon-neutral processes but also enables increased control of the synthesis to avoid undesirable agglomeration of the product. In this study, a 2D porous La0.2Sr0.8CoO3 perovskite was rapidly prepared using a microwave shock method. The rapid entropy increase associated with the microwave process can effectively expose abundant active sites in the La0.2Sr0.8CoO3 structure. Furthermore, the high-energy microwave shock process can precisely introduce Sr 2+ into the lattice of LaCoO3, increasing the number of oxygen vacancies by increasing the oxidation state of Co. The oxygen vacancies introduced by replacing La with Sr can considerably improve the intrinsic catalytic activity of the material. For the OER in alkaline electrolytes, the prepared La0.2Sr0.8CoO3 catalyst displayed an excellent overpotential of 360 mV at 10 mA•cm −2 and a Tafel slope of 76.6 mV•dec −1 . After a long-term cycle test of 30000 s, 97% of the initial current density was maintained. This study presents a facile and rapid strategy for the synthesis of highly active 2D perovskites.

No abstract

Layered double hydroxide (LDH) is widely used in electrocatalytic water splitting due to its good structural tunability, high intrinsic activity, and mild synthesis conditions, especially for flexible fiber-based catalysts. However, the poor stability of the interface between LDH and flexible carbon textile prepared by hydrothermal and electrodeposition methods greatly affects its active area and cyclic stability during deformation. Here, we report a salt-template-assisted method for the growth of two-dimensional (2D) amorphous ternary LDH based on dip-rolling technology. The robust and high-dimensional structure constructed by salt-template and fiber could achieve a carbon textile-based water splitting catalyst with high loading, strong catalytic activity, and good stability. The prepared 2D NiFeCo-LDH/CF electrode showed overpotentials of 220 mV and 151 mV in oxygen evolution and hydrogen evolution reactions, respectively, and simultaneously had no significant performance decrease after 100 consecutive bendings. This work provides a new strategy for efficiently designing robust, high-performance LDH on flexible fibers, which may have great potential in commercial applications.