Rietveld Refinement, Morphology, and Optical and Photoluminescence Properties of a β-Ag_1.94Cu_0.06MoO₄ Solid Solution

Abstract

Corner-truncated cubic β-Ag 1.94 Cu 0.06 MoO 4 microcrystals were synthesized using the hydrothermal method. These were investigated by X-ray diffraction, confirming obtention of the spinel structure Fd3̅ m. Through Raman spectroscopy are confirmed all modes for the point group of O h 7. The E gap shows a decrease of the band gap from 3.20 to 3.07 eV, with reduction of the conduction band occurring from −0.20 eV (β-Ag 2 MoO 4 ) to −0.13 eV (β-Ag 1.94 Cu 0.06 MoO 4 ), suggesting a p-type behavior for the Cu 2+ ion. The fieldemission scanning electron microscopy images confirm the morphological changes for β-Ag 2 MoO 4 , where potato-like microcrystals were found. Meanwhile, corner-truncated cubic microcrystals for β-Ag 1.94 Cu 0.06 MoO 4 . The photoluminescence (PL) spectrum confirms the increase in the PL emission for β-Ag 1.94 Cu 0.06 MoO 4 , with suppression of the deep defects occurring in the structure caused by oxygen and silver atoms. In contrast, the green region is intensified because of distortions of the Ag−O and Mo−O bonds. Therefore, the β-Ag 1.94 Cu 0.06 MoO 4 solid solution has PL emission with CCT (4510 K) and CIE coordinates (x = 0.372 and y = 0.433), which could be interesting properties for applications as light-emitting diodes.

Effect of different synthesis routes on the morphology, optical, colorimetric, and photocatalytic properties of β-Ag2MoO4 microcrystals

“…According to the digital photos, such changes were altered as changes in pigmentation between the materials obtained, for shades of light brown to dark brown, which are available in Table 5. Notably, the changes in microcrystal pigmentation were perfectly correlated From the values of colorimetric coordinates (L*, a*, and b*) of the β-Ag₂MoO₄ microcrystals obtained by the CP, SC, HSIIFC, and CH synthesis methods, it is also possible to determine the energy difference (∆E), the chromaticity (C) and the hue angle (Hº), using Equations (8)(9)(10).…”

“…In particular, the molybdates with the specific molecular formula X2MoO4, X = Li, Tl, and Ag. In particular, the use of silver (Ag) as a monovalent cation that leads to the formation of alpha-or beta-disilver molybdate (-Ag2MoO4) or (β-Ag2MoO4) crystals has been reported very recently in the literature in different papers [5][6][7][8][9][10][11][12].…”

Experimental and Theoretical Correlation of Modulated Architectures of β-Ag2MoO4 Microcrystals: Effect of Different Synthesis Routes on the Morphology, Optical, Colorimetric, and Photocatalytic Properties

“…In particular, the molybdates with the specific molecular formula X 2 MoO 4 , X = Li + , Tl + , and Ag + . In particular, the use of silver ions (Ag + ) as monovalent cation leads to the formation of alpha-disilver molybdate (α-Ag 2 MoO 4 ) crystals or beta-disilver molybdate (β-Ag 2 MoO 4 ) crystals has been reported very recently in the literature in different papers [10][11][12][13][14][15][16][17].…”