Double role of CTAB as a surfactant and carbon source in Ni-Mo2C/GA composite: As a highly active electrocatalyst for hydrogen evolution reaction

Hydrogen (H2) is considered one of the energy sources and carriers of the future but its production on a big scale will be difficult for the foreseeable future. The electrocatalytic activity of materials strongly affects the watersplitting reaction. This present work describes the synthesis of a novel Ni-Mo2C/GA composite by hydrothermal and followed by a carbonization process. The dual role of CTAB in the synthesis of Mo2C acts as a surfactant and carbon source, resulting in improved morphology and hydrogen evolution reaction (HER) performance. The morphological images highlight the role of CTAB used for the synthesis of pure Mo2C and the characterization techniques demonstrate the carbon role of CTAB (carbon supplier) in Mo2C. The as-synthesized Mo2C was further incorporated with Ni and graphene aerogel (GA) to get a Ni-Mo2C/GA composite. The synthesized pure Mo2C, Ni-Mo2C, and Ni-Mo2C/GA composite were examined for the HER using a 0.5 M H2SO4 electrolyte. The NiMo2C/GA composite demonstrated improved current density and low overpotential (61 mV@10 mA/cm2), low Tafel slope (52 mV/dec), enhanced active surface area, and stunning stability up to 2000 cycles without deactivation. Our findings reveal the cost-effective synthesis of Ni-Mo2C/GA composite as an effective cathode material for HER applications.

Automated summary

This study reports the synthesis of a novel Ni-Mo2C/GA composite by hydrothermal and carbonization process, which exhibits improved morphology and hydrogen evolution reaction (HER) performance. The dual role of CTAB in the synthesis of Mo2C as a surfactant and carbon source resulted in enhanced material properties. The Ni-Mo2C/GA composite, obtained by incorporating Ni and graphene aerogel (GA), showed improved current density, low overpotential, low Tafel slope, enhanced active surface area, and excellent stability.