Enhanced Electrocatalytic Hydrogen Evolution Activity in Single-Atom Pt-Decorated VS₂ Nanosheets

Abstract

Enhancing catalytic activity by decorating noble metals in catalysts provides an opportunity for promoting the electrocatalytic hydrogen evolution reaction (HER) application. However, there are few systematic studies on regulating the structures of noble metals in catalytic materials and investigating their influence on HER. Herein, Pt catalysts with different structures including single atoms (SAs), clusters, and nanoparticles well-controllably anchored on VS2 nanosheets through a cost-effective optothermal method are reported, and their HER performance is studied. The most efficient Pt-decorated VS2 catalyst (with both Pt SAs and clusters) delivers an overpotential of 77 mV at 10 mA cm–2, close to that of Pt/C (48 mV). However, the optimal mass activity of Pt (normalizing to Pt content) is obtained from only SA Pt-decorated VS2 (i.e., 22.88 A mgPt –1 at 200 mV) and is 12 times greater than that of the Pt/C (1.87 A mgPt –1), attributed to the greatly enhanced Pt utilization. Additionally, the theoretical simulations reveal that Pt SA decoration makes the adsorption free energy of H* closer to the thermoneutral value and improves the charge-transfer kinetics, significantly enhancing HER activity. This work offers a pathway to prepare the desired catalyst based on synergy of Pt structures and VS2 and reveals the intrinsic mechanism for enhancing catalytic activity, which is important for HER applications.

Electronic structure and charge-density wave transition in monolayer VS2

“…Especially vanadium chalcogenides demonstrate variation of CDW transition temperatures depending on film thickness and stoichiometry, it is of interest to apply them for CDW-based devices near room temperature. Finally, vanadium chalcogenides attract much attention as metallic TMDCs for their surface reactivity with gases and ions for next-generation renewable energy applications [36,64]. One important approach is to analyze the valence band structure change along with the various chemical states under the ambient conditions for understanding the efficient catalytic electrode performances.…”

Recent Advances on Transition Metal Dichalcogenides for Electrochemical Energy Conversion

“…Zhang and co‐workers have decorated Pt atoms onto the VS 2 basal plane via the photothermal irradiation. [ 71 ] The structure of the as‐synthesized hybrids can be well modulated by the xenon lamp/sunlight irradiation. Different configurations of the isolated Pt atoms on VS 2 basal plane have been proposed, including Pt atoms substituting V atoms and Pt atoms absorbed on VS 2 .…”

“…For example, Yang and co‐workers have distinguished single S vacancy (V s ), double S vacancy (V 2s ), and single Mo vacancy (V Mo ) on the MoS 2 nanosheet. [ 42 ] Individual Pt atoms on VS 2 nanosheets can be easily discerned in AC‐HAADF‐STEM because of the obvious atomic contrast between Pt and V. [ 71 ] Energy‐dispersive X‐ray spectroscopy and/or electron energy loss spectroscopy are always performed along with the STEM for confirming the composition of target TMCDs. [ 72 ]…”

Engineering Single Atom Catalysts to Tune Properties for Electrochemical Reduction and Evolution Reactions

“…[ 145 ] Thus, ECM@Ru electrocatalyst activity tuning can be governed by controlling carbon matrix support structure. Zhu et al [ 146 ] developed Single Atom Pt decorated, variably layered VS 2 NSs grown on carbon paper (Pt/VS 2 /CP) for HER performance, with Pt concentration controlled by chloroplatinic acid concentration ( x ‐Pt, in mM) during synthesis. Figure 19j depicts how Pt SACs affect Pt/VS 2 /CP HER activity by comparing Pt/VS 2 /CP LSV curves with those of pristine carbon paper (CP), VS 2 /CP, 20% Pt/C, and Pt/VS 2 /CP, immediately corroborating previous literature by finding that pristine CP is nearly inactive.…”