Surfactant-Assisted Electrodeposition of Manganese Carbonate for Efficient Hydrogen Evolution in an Acidic Medium

Developing cost-effective, eco-friendly electrocatalysts for the hydrogen evolution reaction (HER) is essential for sustainable hydrogen production. In view of this, MnCO 3 is reported as an electrocatalyst for HER. However, the HER performance of MnCO 3 is inferior to the benchmark catalyst, Pt/C and requires further improvement. This study significantly enhances the HER performance of MnCO 3 via the electrochemical interfacial templating technique. MnCO 3 is electrodeposited on pencil graphite at 2 V using three surfactants: cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and triton X-100 (TX-100) at different amounts. Uniform and stable deposits are obtained with 500 mg of surfactant. While structural analysis confirms successful deposition of MnCO 3 , microscopic studies reveal the surfactant-dependent textural properties of MnCO 3 . MnCO 3 electrodeposited with 500 mg of SDS demonstrates outstanding HER performance (an overpotential of 51 mV at 10 mA cm −2 ( η 10 ), comparable to Pt/C, 59 mV) and it outperforms Pt/C at higher current densities. In addition, a progressive improvement in the HER performance is observed on continuous operation (>50 h of chronoamperometry at η 10 and 5000 cycles of linear sweep voltammogram), which indicates excellent long-term stability and durability.