Layered Noble Metal Dichalcogenides: Tailoring Electrochemical and Catalytic Properties

Abstract

Owing to the anisotropic nature, layered transition metal dichalcogenides (TMDs) have captured tremendous attention for their promising uses in a plethora of applications. Currently, bulk of the research is centered on Group 6 TMDs. Layered noble metal dichalcogenides, in particular the noble metal tellurides, belong to a subset of Group 10 TMDs, wherein the transition metal is a noble metal of either palladium or platinum. We address here a lack of contemporary knowledge on these compounds by providing a comprehensive study on the electrochemistry of layered noble metal tellurides, PdTe and PtTe, and their efficiency as electrocatalysts toward the hydrogen evolution reaction (HER). Observed parallels in the electrochemical peaks of the noble metal tellurides are traced to the tellurium electrochemistry. PdTe and PtTe can be discriminated by their distinct reduction peaks in the first cathodic scans. Considering the influence of the metal component, PtTe outperforms PdTe in aspects of charge transfer and electrocatalysis. The heterogeneous electron transfer (HET) rate of PtTe is an order of magnitude faster than PdTe, and a lower HER overpotential of 0.54 V versus reversible hydrogen electrode (RHE) at a current density of -10 mA cm is evident in PtTe. On PdTe and PtTe surfaces, adsorption via the Volmer process has been identified as the limiting step for HER. A general phenomenon for the noble metal tellurides is that faster HET rates are observed upon electrochemical reductive pretreatment, whereas slower HET rates occur when the noble metal tellurides are oxidized during pretreatment. PtTe becomes successfully activated for HER when subject to oxidative treatment, whereas oxidized or reduced PdTe shows a deactivated HER performance. These findings provide fundamental insights that are pivotal to advancing the field of the underemphasized TMDs. Furthermore, electrochemical tuning as a means to tailor specific properties of the TMDs is advantageous for the development of their future applications.

Topological Type‐II Dirac Semimetal and Superconductor PdTe2 for Ethanol Electrooxidation

“…Te (VI) and Te (0) can also be seen from Figure S1b, Supporting Information. These results correspond with the previous report …”

“…These results correspond with the previous report. [25] The surface morphologies were further studied by scanning electron microscopy (SEM). The SEM image of bulk PdTe 2 is shown in Figure 2a, indicating the PdTe 2 adopts to a layer structure.…”

Two‐Dimensional Noble‐Metal Chalcogenides and Phosphochalcogenides

“…determined that the catalytic activity of platinum dichalcogenides for the hydrogen evolution reaction (HER) increases with the size of the chalcogen atoms. PtTe 2 outperforms PdTe 2 as a result of the lower overpotential barrier of 0.54 eV versus the reversible hydrogen electrode (RHE) and also because it is less prone to tellurium stripping . The performance of the bulk material towards the HER is reasonable, but can be enhanced by increasing the amount of edge sites or by reducing the bulk thickness.…”

“…The NMDCs also showed an outstanding performance as sensors, for example, for pressure or for specific molecular species . Their chemistry, which includes highly anisotropic structural features, low‐energy differences between different polymorphs, controllable phase changes, and catalytic properties, differs from that of the transition‐metal dichalcogenides (TMDCs), such as MoS 2 and WSe 2 . This is caused by electron correlation and relativistic effects, which render their theoretical investigation challenging.…”

Zweidimensionale Edelmetallchalkogenide und ‐phosphochalkogenide

“…Die NMDCs zeigen eine herausragende Leistung als Sensoren, zum Beispiel für Druck oder bestimmte molekulare Spezies . Ihre Chemie, die sehr anisotrope strukturelle Merkmale, geringe Energiebarrieren zwischen den Strukturtypen, kontrollierbare Phasenübergänge und katalytische Eigenschaften beinhaltet, unterscheidet sich von den Übergangsmetalldichalkogeniden (TMDCs) wie MoS 2 oder WSe 2 . Ein Grund dafür ist der Einfluss von Elektronen‐Korrelationseffekten und relativistischen Effekten, wodurch die Untersuchung dieser Materialien seitens der Theorie herausfordernd ist.…”