Investigation of the photocatalytic and optical properties of the SrMoO4/g-C3N4 heterostructure obtained via sonochemical synthesis with temperature control.

In this work, nanomaterials of the SrMoO4/g-C3N4 heterostructure were synthesized in a single step by the sonochemical method with controlled temperatures. Structural and morphological investigations indicate the formation of heterojunctions, revealing the presence of g-C3N4 (CN) in the heterostructures and an interface region between the phases. Optical analyzes show broadening of the wavelength absorption range and a decrease in the photoluminescence (PL) intensity of the heterojunctions compared to the CN emission spectrum, proving a decrease in the recombination of the photogenerated charges. The results of the photocatalytic tests indicate that the insertion of CN promoted photocatalytic degradation of the Methylene Blue (MB), Rhodamine B (RhB) and Crystal Violet (CV) organic contaminants, up to 99.58%, 100% and 98.65%, respectively. The mixture of dyes used and reuse cycles was performed to analyze the applicability of the compounds in a real situation.

Integration of experiment and computational modeling on the Tb doping process in CaMoO4 obtained by USP method: An efficient way to obtain photoluminescent materials.

In this paper, we present a combined experimental and theoretical study to disclose, the structure, electronic and optical properties of CaMoO 4 :xTb 3+ ( x = 1%, 2%, and 4%) microspheres. The microspheres were prepared by ultrasonic spray pyrolysis method and characterized by experimental and theoretical techniques. Theoretical calculations and XRD patterns indicate that these crystals have a scheelite-type tetragonal structure. The morphology of the CaMoO 4 :xTb 3+ ( x = 1%, 2% and 4% mol) samples were investigated from the FEG-SEM results and the formation of microspheres with a spherical shape were observed. The optical properties were investigated by UV-Vis and PL spectroscopy, as well as the chromaticity coordinates of these compounds. This also allowed us to understand the charge transfer process that happens in the singlet state and the excited states, generating the photoluminescence emissions of the Tb doping process in CaMoO 4 microspheres.

Europium(III) concentration effect on the spectroscopic and photoluminescent properties of BaMoO(4):Eu.

BaMoO(4):Eu (BEMO) powders were synthesized by the polymeric precursor method (PPM), heat treated at 800 degrees C for 2 h in a heating rate of 5 degrees C/min and characterized by powder X-ray diffraction patterns (XRD), Fourier Transform Infra-Red (FTIR) and Raman spectroscopy, besides room temperature Photoluminescence (PL) measurements. The emission spectra of BEMO samples under excitation of 394 nm present the characteristic Eu(3+) transitions. The relative intensities of the Eu(3+) emissions increase as the concentration of this ion increases from 0.01 to 0.075 mol, but the luminescence is drastically quenched for the Ba(0.855)Eu(0.145)MoO(4) sample. The one exponential decay curves of the Eu(3+ 5)D(0)-->(7)F(2) transition, lambda (exc) = 394 nm and lambda (em) = 614 nm, provided the decay times of around 0.54 ms for all samples. It was observed a broadening of the Bragg reflections and Raman bands when the Eu(+3) concentration increases as a consequence of a more disordered material. The presence of MoO(3) and Eu(2)Mo(2)O(7) as additional phases in the BEMO samples where observed when the Eu(3+) concentration was 14.5 mol%.