Chemical scission derived two-dimensional NiFe layered double hydroxide nanoswords for efficient water splitting

Abstract

Advanced electocatalysts have been designed and reported for water electrolysis. However, significant challenge and gap remains for the design and fabrication of highly efficient, robust yet cost-effective multifunctional catalyst. One of the fundamentals of the effective catalysts lies in the effective active sites capable of lowering the adsorption energy required for the intermediate steps. In this work, for the first time, two-dimensional (2D) NiFe layered double hydroxide (NiFe-LDH) nanoswards is reported by chemical scission of NiFe layered double hydroxide nanosheets with silicon tetrachloride (SiCl4). Si is incorporated into the structure of NiFe-LDH nanoswords with the emergence of new bond of Si–O-M. In situ Raman together with theoretical calculation confirmed that Tailored-NiFe-LDH has a more active internal structure than NiFe-LDH nanosheet, favoring the formation of active intermediates. The new Si–O-M bond lowers the energy required for the adsorption process. Tailored-NiFe-LDH shows low η10 of 280 mV and Tafel slope of 52.11 mV dec−1 at 10 mA cm−2 (Oxygen evolution reaction). When used as water splitting catalyst in a full cell, Tailored-NiFe-LDH shows good activity and stability. We believe this simple and rapid synthesis route is proposed to prepare novel catalysts with good electrical conductivity, and opens new strategy to tailor 2D LDH materials and other similar hydroxyl-rich superstructures and composites.