Co0.75Mo3S3.75/CoS2@2D-MoS2 Nanosheets on Carbon Cloth: A Progressive Binder-Free Electrocatalyst for Hydrogen Evolution Reaction

The development of ultrathin non-noble metal dichalcogenide electrocatalysts with tunable physical properties such as phase transformations, defect engineering, and activating plane edges is essential in order to enhance their electrocatalytic performance for water splitting applications. In this present work, we account to report a facile approach to cationic modulations through a single-step hydrothermal approach for the fabrication of a two-dimensional (2D) self-assembled ultrathin Co0.75Mo3S3.75/CoS2 (Co–Mo–S) @MoS2 nanoflowers directly grown on carbon fibre cloth. The systematic physicochemical relationship of cobalt ion modulations into MoS2 nanoflowers (Co/Mo/S) enabled the formation of flower-like Co–Mo–S@MoS2 ultrathin nanosheets with enhanced active sites, resulting in enhanced electrocatalytic contribution for hydrogen evolution reaction. The synthesised catalyst exhibited an ultralow overpotential value of 43 mV (RHE) at 20 mA/cm2, very small Tafel value of ∼36.6 mV/dec, and long durability/stability of 51 h of electrolysis. As a whole, these presented results demonstrate a rational construction of 2D ion modulated MoS2 ultrathin nanosheet electrodes that are beneficial for sustainable energy storage devices, which could be potentially extended to other dimensional MoS2 based materials.