In Situ Observation of Thermally Induced Structural Transitions in Vacancy-Doped Cuprous Telluride (Cu_2–xTe) Nanowires Using Raman Spectroscopy

Abstract

A fundamental understanding of the thermal stability of vacancy-doped cuprous telluride nanocrystals (Cu 2−x Te NCs) will be conductive to their exploitation in plasmon-related applications. However, the thermally induced structural and Raman spectral changes of Cu 2−x Te NCs have remained fairly unexplored so far. Here, temperature-induced structural transitions of Cu 2−x Te nanowires (NWs) are studied by in situ Raman spectroscopy from −190 to 530 °C. Results reveal a dramatic temperature dependence of Raman signatures of Cu 2−x Te NWs, serving as a potent indicator for their structures and structural transitions. The hexagonal weissite-to-orthorhombic phase transition takes place in the cooling process from 25 °C to −190 °C. An intermediate state of high degree of disorder with featureless Raman spectra is observed before its dissociation into the elemental Cu and the high-temperature phase above 480 °C. This work provides fundamental insights into the thermally induced structural stability of Cu 2−x Te NWs and will further stimulate new exploration of their plasmon-related practical applications.

Biodegradable Amorphous Copper Iron Tellurite Promoting the Utilization of Fenton-Like Ions for Efficient Synergistic Cancer Theranostics

“…In brief, Cu 2– x Te nanowires (NWs) were first synthesized using Te NWs as the template that were subsequently converted into Cu 2‑x Te NWs in the presence of Cu 2+ and l -ascorbic acid (Supporting Information (SI) Figure S1). , Then, the introduction of FeCl 3 with strong oxidation ability converts the Te 2– of Cu 2– x Te NWs to TeO 3 2– along with the formation of Fe 2+/3+ , and the high surface energy of amorphous structure induces the formation of spherical a-CFT NPs. Transmission electron microscopy (TEM) image shows the well-dispersed spherical NPs with an average diameter of 14.9 nm (Figure (A,i) and SI Figure S2).…”

“…Cu 2– x Te NWs were synthesized following a Te template method reported in our previous work. , First, tellurium nanowires (Te NWs) were synthesized following a hydrothermal synthetic route. Typically, 1.0 g of PVP and 92.2 mg of Na 2 TeO 3 were added to 33 mL DI water, followed by the sequential addition of 3.33 mL ammonium hydroxide solution and 1.67 mL hydrazine hydrate under magnetic stirring.…”

One‐pot hydrothermal synthesis of Cu2Te/NiTe nanocomposite materials: A structural, morphological, and optical study

“…The Raman peak at 131 cm −1 is referred to as the E Raman active mode of Cu 2 Te that infers the change in bond length of the molecules 32 . The shift at 536 cm −1 is due to the hexagonal Cu 2− x Te phase 33 . The shift detected at 738 cm −1 is referred to Te symmetric stretching mode, in which the bond between the molecules is either compressed or expanded 34 .…”

Advances of 2D‐Enabled Photothermal Materials in Hybrid Solar‐Driven Interfacial Evaporation Systems toward Water‐Fuel‐Energy Crisis

“…[142] Cu 2-x Te is a direct band gap material that can be tuned by changing the stoichiometry, from 1.1 to 1.5 eV. [143][144][145] It is a p-type semiconductor with high degeneracy, where holes (positive charges) produced by the copper vacancy promote its broad-band plasmonic characteristic in the near-infrared range. [145] Cu 2-x Te is a potential photothermal material for a number of applications, such as tumor photothermal ablation, sunlight-driven vapor production, and sea-water desalination.…”