Effective solar-driven overall electrocatalytic water-splitting by Co-doped 1T/2H MoS2 nanoparticles

Abstract

Electrodes made from easily accessible earth materials, which are both strong and stable, are becoming popular for large-scale water-splitting in green hydrogen production. This work employed cobalt (Co) doped molybdenum disulfide (MoS₂) nanoparticles (NPs) as an electrode to facilitate solar-driven electrocatalytic water-splitting. We synthesised spherical-shaped pure and Co-doped 1T/2H MoS₂ NPs using a straightforward, cost-effective, one-step hydrothermal approach. It was found that the 0.2 mM Co-doped 1T/2H MoS₂ (MSC-2) electrode possessed rich active sulfur sites, efficient charge transfer characteristics between the electrolyte and the electrode, and a significant surface area. These characteristics contributed to enhance the performance of MSC-2 in both hydrogen evaluation reaction (HER) and oxygen evaluation reaction (OER), resulting in low overpotentials of 167 and 263 mV (vs. reverse hydrogen evaluation (RHE)), respectively. The electrode demonstrated excellent stability during the 25 h chronoamperometry (CA) tests conducted in an alkaline electrolyte. The MSC-2 electrocatalyst demonstrates impressive efficacy in overall water splitting in alkaline environments. It achieves an overpotential of 1.54 V (V vs. RHE) and maintains stability for 25 h at a current density of 10 mA cm⁻². In practical terms, a solar panel (1.54 V) can drive this effective overall water-splitting, demonstrating its capacity to store solar energy as O₂ and H₂ energies. In summary, these MSC-2 NPs possess the potential to establish an innovative method for efficiently splitting water into oxygen and hydrogen on a massive scale.