Water splitting stands out as a highly promising avenue for powering our planet without the risk of environmental pollution. Despite its potential, the process faces a thermodynamic uphill battle. Researchers are actively addressing this challenge to enhance energy efficiency by focusing on the development of catalysts that can efficiently drive the hydrogen evolution reaction (HER) and oxygen evolution reactions (OER) [1].

In this regard, 2D layered materials such as transition metal phosphorus trichalcogenides (MPX₃; X=S, Se) have recently got copious attention. Their remarkable properties, including atomic-scale thickness, a direct band gap, cost-effective synthesis, and exceptional electronic and mechanical properties, position them as promising candidates for diverse fundamental studies such as electrocatalysis, photocatalysis and hydrogen storage [2].
In this presentation, we will discuss two impactful strategies aimed at boosting the efficiency of our innovative catalyst: i) Confinement and ii) controllable selenium enrichment. Confinement ensures selectivity and stability by averting surface deterioration and particle aggregation of the catalyst [3]. Furthermore, incorporating additional active sites within the 2D layer of the catalyst can favour the overall water splitting mechanism, amplifying the system's performance. Then, controllable Se enrichment on the surface of a catalyst enhances the charge transfer process during HER and optimize the catalyst surface to become thermodynamically/kinetically favourable to produce H₂ gas [4].

In this comprehensive exploration, we delve into the development of a versatile array of Mo-confined Se-enriched manganese-based 2D structures. From MnPSe₃ to Ex-MnPSe₃ (exfoliated MnPSe₃), Mo-Se-MnPS₃ (Mo-confined Se-enriched MnPS₃), and Mo-MnPS₃ (Mo confined MnPSe₃) our research unfolds the potential of these structures for applications in the field of energy conversion. Extensive chemical-physical and optical characterisation was carried out. SEM and HR-TEM, XRD, EDX, Raman, and Synchrotron based XPS analyses provide a detailed understanding of these innovative structures.

Beyond characterization, our research highlights the exceptional electrocatalytic properties of these materials in the hydrogen evolution reaction (HER) via electrochemical water splitting, as evidenced by their high electroactive surface area, low Tafel slope and impressive performance in linear sweep voltammetry (LSV) measurements. This samples also exhibit robust results in stability test performed by cyclic voltammetry.

These results allowed us to state that by using confined catalysis it is possible to increase the performance and stability of a system by increasing its current delivery and the resulting production of green hydrogen. Moreover, the controllable Se-enrichment enhances the efficient conversion of H⁺ into H₂, offering an exciting avenue for energy conversion.

This study significantly contributes to advancing the understanding of MPX₃ nanomaterials and confined catalysis, offering transformative insights for future applications in the field of energy conversion and green hydrogen production.