Charge Transfer-Mediated Blue Luminescence in Plasmonic Ag–Cu₂O Quantum Nanoheterostructures

Abstract

Metal–semiconductor hybrid nanoheterostructures have the possibility to exhibit new synergic properties other than the combination of properties from discrete components due to the interaction of metal and semiconductor components at the interfaces. Here, we have synthesized Ag–Cu2O eyeball-shaped quantum nanoheterostructures with diameter ranging between 8 and 12 nm using a single-step low-cost solvothermal process. It is observed that the presence of a minimum 3% of Ag is required for the formation of Ag–Cu2O quantum nanoheterostructures. The formation of nanoheterostructures has introduced new synergic properties like intense blue luminescence and surface-enhanced Raman scattering due to the interactions between Ag and Cu2O atoms at the interfaces. The significant presence of charge transfer through the interfaces is identified from the peak shift of Raman modes. The increase in the electron density at the metal surface due to the charge transfer and the recombination of these electrons with sp- or d-band holes of Ag could be the effective mechanism of the observed blue luminescence. The blue luminescence of Ag–Cu2O quantum nanoheterostructures together with its low band gap value (≈2.3 eV) is believed to have important applications in optoelectronic devices.

Modulating Charge Carrier Dynamics among Anisotropic Crystal Facets of Cu2O for Enhanced CO2 Photoreduction

“…UV–visible spectrum of as-prepared cubic and edge-truncated Cu 2 O samples is shown in Figure a. Due to the relatively large particle size of crystals (edge length ∼500 nm), a broad and strong light scattering band dominates the absorption spectra of both these samples covering an adequate range of wavelength from 475 to 725 nm, which is consistent with previous reports for Cu 2 O particles. − The absorption edge of the cubic Cu 2 O sample is located at about 660 nm, whereas a redshift of the light absorption edge is observed for the edge-truncated cubic Cu 2 O sample. A relative shift in the band position of cubic and edge-truncated crystal is ascribed to the difference between the thickness and size of the particles.…”

Rational Design and Synthesis of Ag−Cu2O Nanocomposites for SERS Detection, Catalysis, and Antibacterial Applications

“…Through solvothermal synthesis, Ghose et al. prepared Janus Ag−Cu 2 O nanocomposites with an eyeball‐like morphology [40] . The solvothermal reaction was performed at 140 °C in ethanol for 2 h with metal acetates (i. e., Ag(CH 3 COO) and Cu(CH 3 COO) 2 ) as the precursors and dextrose as the reducing agent.…”

“…Through solvothermal synthesis, Ghose et al prepared Janus AgÀ Cu 2 O nanocomposites with an eyeball-like morphology. [40] The solvothermal reaction was performed at 140 °C in ethanol for 2 h with metal acetates (i. e., Ag(CH 3 COO) and Cu(CH 3 COO) 2 ) as the precursors and dextrose as the reducing agent. Only small amounts of Ag(CH 3 COO) was used to create an eyeball-shaped hybrid, where a small Ag particle is attached to a larger Cu 2 O sphere.…”

Optimizing Green Synthesis of Hydrotalcite – Silver Nanoparticles using Syzygium Nervosum based Reducing Agent

“…Despite the great benefits of AgNPs, preserving them as well as using them at nano sizes is a difficult problem because their size is close to the size of cells [14] . To tackle this problem, there are some types of materials such as ZrO 2 , [15] Cu 2 O, [16] ZnO, [17] Fe 2 O 3 , [18] etc. are investigated as AgNPs’ carriers.…”