Collaborative activation of basal and edge sites in Pt doped 1T phase MoS2 quantum sheets for highly efficient alkaline HER

Monolayer Pt doped 1T phase MoS 2 quantum sheets (Pt/1T–QSs) were synthesized. • The Pt/1T–QSs show 70% metallic 1T phase with a lateral size of ca. 6.1 nm. • Pt doping collaboratively activate both basal and edge sites of MoS 2 for HER. • The Pt/1T–QSs exhibit exceptional alkaline HER performance. Transition metal disulfides (TMDs) are considered as promising alkaline hydrogen evolution reaction (HER) catalysts; however, their catalytic activity remains far from satisfactory. This is primarily due to the relatively low HER activity of both basal and edge sites. Herein, a strategy of synthesizing Pt doped 1T phase MoS 2 quantum sheets (Pt/1T–QS) for co-activating both basal and edge sites is reported for addressing the aforementioned issue. The developed strategy employs a wet-chemical synthetic route encompassing a hydrothermal doping reaction, a subsequent chemical lithiation, and a final liquid exfoliation process to prepare the desired Pt/1T–QSs (monolayered with lateral size of ca. 6.1 nm). Notably, the Pt/1T–QSs demonstrate exceptional alkaline HER performance, presenting a low overpotential of 203 mV at 300 mA cm −2 and excellent durability for over 120 h at 100 mA cm −2 in 1 M KOH. Theoretical calculations reveal that Pt doping induces pronounced up-shifts for the p −/ d –band centers and collaboratively optimized ΔG H at both basal and edge sites in 1T–QS, thereby accelerating water dissociation kinetics and enhancing alkaline HER performance. This work offers a generalizable strategy for overcoming the conventional edge-dominated activity paradigm of TMD-based catalysts and may advance the rational design of high-performance alkaline HER catalysts with multi-site activation. A rational designed catalyst of Pt doped 1T phase MoS 2 quantum sheet (Pt/1T–QS) material was prepared, characterized by monolayer thickness, quantum sized, dominant 1T phase, and uniformly distributed Pt dopants. The Pt doping collaboratively activates both the basal and edge sites of 1T–QS by accelerating water dissociation kinetics and optimizing hydrogen adsorption energies, resulting in outstanding alkaline HER performance. Download: Download high-res image (150KB) Download: Download full-size image