Integrating NiSe-MoSe heterojunctions with N-doped porous carbon substrate architecture for an enhanced electrocatalytic water splitting device.

The development of sustainable energy technologies relies on the exploitation of efficient and durable electrocatalysts for water splitting at high current densities. Our work presents a novel bifunctional catalyst, denoted as NM@NC/CC, which combines the benefits of NiSe-MoSe heterojunctions with nitrogen-enriched porous carbon derived from metal-organic frameworks (MOFs). The integration of these components is designed to harness their combined advantages, which include enhanced electron transfer, improved mass and gas evolution dynamics, and an increased number of catalytically active sites. These features collectively optimize the energetics for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). As a result, the catalyst facilitates rapid kinetics for the overall water-splitting process. The NM@NC/CC demonstrates low overpotentials, requiring only 91 mV for the HER and 280 mV for the OER to reach a current density of 10 mA cm. Even at higher current densities of 100 mA cm for HER and 50 mA cm for OER, the overpotentials are only 159 mV and 350 mV, respectively. Additionally, a two-electrode setup using this catalyst achieves a current density of 10 mA cm with a minimal cell voltage of 1.56 V. The insights gained from this study will contribute to the advancement of electrocatalysts for energy conversion technologies.