Sodium dodecyl sulfate intercalated two-dimensional nickel-cobalt layered double hydroxides to synthesize multifunctional nanomaterials for supercapacitors and electrocatalytic hydrogen evolution

The controllable adjustment of layered double hydroxide layer spacing makes it possible as electrode material for energy storage and electrochemical hydrogen evolution at the same time. However, the lower conductivity and agglomeration significantly hinder its large-scale application as an active electrode material. Here, sodium dodecyl sulfate (SDS) intercalation modification was used to construct LDH derivatives and CoNi-SDS-LDH nanosheets were grown vertically on the nickel foam (NF) surface using in situ growth technique to construct a layered structure of nanosheets supported by nanowires, which effectively enhanced the ion transport effi-ciency and greatly reduced the agglomeration phenomenon of nanosheets. Thanks to the charge rearrangement in LDH and the controlled defects of the nanosheets, the electrode material has good electrochemical perfor-mance. The cycling stability of the CoNi-SDS-LDH self-supported electrode material is 91% after 10,000 cycles at 5 A g-1. Notably, the electrode material showed 98.1% performance retention after 10 h of hydrogen evolution test. It is shown that the anionic modification offers the possibility for large-scale applications of LDH in flexible supercapacitors and electrocatalytic hydrogen precipitation.

Automated summary

The controllable adjustment of layered double hydroxide layer spacing has enabled its use as an electrode material for energy storage and electrochemical hydrogen evolution. However, lower conductivity and agglomeration have limited its large-scale application. In this study, sodium dodecyl sulfate (SDS) intercalation modification was used to construct LDH derivatives with vertically grown CoNi-SDS-LDH nanosheets on a nickel foam surface, resulting in a layered structure supported by nanowires which improved ion transport efficiency and reduced agglomeration. The electrode material demonstrated good electrochemical performance, with a cycling stability of 91% after 10,000 cycles and 98.1% performance retention after 10 hours of hydrogen evolution test. This anionic modification offers the potential for large-scale applications of LDH in flexible supercapacitors and electrocatalytic hydrogen evolution.