# Unconventional-Phase 1T′-Transition Metal Dichalcogenide Monolayers Grown on Amorphous Templates for Highly Efficient Hydrogen Evolution

## TL;DR

Researchers developed a new method to create efficient and stable hydrogen evolution catalysts using transition metal dichalcogenides with a special structure.

## Contribution

A wet-chemical method to synthesize high-phase-purity 1T′-TMD monolayers using amorphous P-doped Pd nanoparticles as templates.

## Key findings

- a-PdP@1T′-MoS2 catalyst achieves −182.3 mV overpotential at 1,000 mA·cm–2 for hydrogen evolution.
- The catalyst maintains stability for over 500 hours at 500 mA·cm–2.
- It supports single-atom Pt dispersion, enhancing electrocatalytic performance.

## Abstract

Hydrogen is a promising clean energy carrier to address
global
energy and environmental challenges. Although platinum (Pt)-based
catalysts are the benchmark for the hydrogen evolution reaction (HER),
their high cost and scarcity limit their widespread application. Two-dimensional
transition metal dichalcogenides (TMDs), particularly with the unconventional
1T′ phase, have emerged as promising alternatives, yet synthesizing
them with high phase purity and stability remains challenging. Here,
by using amorphous phosphorus (P)-doped Pd nanoparticles (a-PdP NPs) as templates, we develop a facile and general
wet-chemical method to synthesize high-phase-purity and stable 1T′-TMD
monolayers (MLs), including MoS2, WS2, and MoWS2, to construct a-PdP@1T′-TMD core–shell
NPs. Experimental and theoretical analyses reveal that the formation
and stabilization of 1T′-MoS2 MLs are attributed
to the strong Pd–S interaction, electron donation from oleylamine,
and amorphous nature of the template. The resulting a-PdP@1T′-MoS2 catalyst exhibits superior HER performance,
requiring an overpotential of only −182.3 mV to achieve 1,000
mA·cm–2 and maintaining high stability for
over 500 h at 500 mA·cm–2, outperforming the
commercial Pt/C and placing it among the best reported MoS2-based catalysts. Impressively, the synthesized a-PdP@1T′-MoS2 can also be used as an efficient
and stable support to grow single-atomically dispersed Pt with further
enhanced HER activity, indicating its promise as a versatile platform
for the design and preparation of advanced electrocatalysts.