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The objective of this study was to investigate the photoluminescence properties of Al4B2O9:M (M = Dy3+, Sm3+, and Tb3+). The solution combustion method was employed to prepare Al4B2O9 doped with M ions. The synthesized aluminum borates were subjected to phase analysis using X-ray diffraction, while their photoluminescence properties were evaluated using a spectrofluorometer. Under excitation at 352 nm, Al4B2O9:Dy3+ exhibited emission peaks at 484, 578, and 701 nm. Similarly, when excited at 402 nm, Al4B2O9:Sm3+ emitted light at 563, 599, 645, and 702 nm. Finally, upon excitation at 238 nm, Al4B2O9:Tb3+ emitted light at 489, 544, 588, and 622 nm. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the photoluminescence properties of Bi3+-activated Sr3B2O6. Pure Sr3B2O6 and Bi3+-doped Sr3B2O6 were synthesized by a solution combustion method. The phase and photoluminescence analyses of the borates that were synthesized were determined by using X-ray diffraction and a spectrofluorometer respectively at room temperature. It was observed that the synthesized Bi3+-doped Sr3B2O6 emitted blue light (441 nm) upon excitation with 366 nm. Finally, the Stokes shift of Sr3B2O6:Bi3+ was calculated and found to be 4646 cm–1. [ABSTRACT FROM AUTHOR]

Today, increasing dyes pollution is of great importance for life. Leaving the dyes used in industries such as textiles without being discharged pollutes other water sources. In order to prevent this, different methods are used in the literature. In this study, SrAl2B2O7, a borate metal, was used to remove methyl blue (MB), an anionic dye, by batch adsorption method. Strontium aluminoborate (SrAl2B2O7) was prepared using a solution combustion method at 950 °C for 4 h in air. The prepared adsorbent was characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The particle morphology of the adsorbent was investigated using scanning electron microscope (SEM). By using N2 adsorption–desorption, the Brunnauer, Emmet, and Teller (BET) specific surface area was found to be 1.9578 m2 g−1. The surface charge of the dye-adsorbed SrAl2B2O7 was determined based on zeta-potential measurements. Langmuir (R2=0.9897), Freundlich (R2=0.985), Dubinin & Radushkevic (R2=0.976), Scatchard (R2=0.881), Temkin & Pyzhev (R2=0.978) isotherms were calculated in the study. SrAl2B2O7 showed good adsorption performance for methyl blue (MB) with maximum adsorption capacities of 29.069 mg g−1 (Langmuir). Adsorption processes were also studied in detail. Thermodynamic and kinetic models; pseudo-first-order (R2=0.415), pseudo-second-order (R2=0.999), Elovich (R2=0.968) showed that adsorption using SrAl2B2O7 in MB removal is endothermic and pseudo-second order. [ABSTRACT FROM AUTHOR]

Abstract Sr2Mg(BO3)2 was prepared by a solution combustion method at 900 °C for 6 hour in air. The prepared adsorbent was characterized by X-Ray Diffraction (XRD). The XRD pattern of Sr2Mg(BO3)2 is in agreement with the ICDD File No: 01-076-9795. The particle morphology of the adsorbent was investigated by scanning electron microscope (SEM). The average size of particles is about 3–10 µm. The Congo red dye was removed from aqueous solution using Sr2Mg(BO3)2. The effect of time, initial concentration, pH, temperature and dosage on adsorption were investigated. The Freundlich model fitted according to equilibrium data and maximum adsorption capacity is 886.952 mg/g. According to theories of pseudo-second-order kinetics, the removal procedure involves chemical adsorption. According to the thermodynamic data, negative ΔG values indicated that adsorption of Sr2Mg(BO3)2 occurred spontaneously and negative ΔH values, the adsorption process was exothermic. Sr2Mg(BO3)2 is a useable material for Congo red dye removal. [ABSTRACT FROM AUTHOR]