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In this work, various nano-sized samples of Y₂O₃, Y₂O₃:Eu and Y₂O₃:Eu, Sr were prepared by urea solution combustion method. Then the resultant nanopowders were investigated by means of X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR) and photo-luminescence emission spectra. Furthermore, the CIE color coordinate of samples were calculated from photoluminescence emission spectra. Results showed that by doping of strontium, the photoluminescence intensity and chromaticity of Y₂ O₃:Eu phosphor was enhanced while crystallite size was decreased.

A series of single-composition phosphors Sr₃B₂O₆: Tb${}^{3+}$, Eu${}^{3+}$have been prepared via a combustion method. The structural and luminescent properties of phosphor are investigated in detail. Under ultraviolet radiation excitation, Sr₃B₂O₆: Tb${}^{3+}$, Eu${}^{3+}$ phosphors show the characteristic $f$–$f$ transitions of both Eu${}^{3+}$ and Tb${}^{3+}$ and give a bright yellow emission. The investigations on photoluminescence and lifetime of Eu${}^{3+}$ show that there are two sites of luminescence center of Eu${}^{3+}$ in host matrix. The energy transfer from Tb${}^{3+}$ ion to Eu${}^{3+}$ ion are observed and the mechanism of energy transfer is dipole–quadrupole interaction.

In this paper, low temperature, economical sol–gel combustion method was adopted to synthesize wollastonite ceramic. Calcium nitrate tetrahydrate and tetraethyl orthosilicate were taken as source for Ca and Si, while citric acid and nitric acid were used as chelating/combustion agents. The yielded powder calcined at 600${}^{\circ }$C for 4 h was characterized by FTIR, XRD and SEM techniques. Results showed that the citrate combustion method was the most efficient method to prepare wollastonite at low temperature. Moreover, in vitro bioactivity test performed in simulated body fluid (SBF) showed good bioactivity of synthesized wollastonite ceramics.

The ZnO nanoparticles were synthesized using marine brown algae (Cystoseira) extract and calcination. For comparison, combustion, and sol–gel methods were employed to synthesize nanoparticles to use as material in dye-sensitized solar cells (DSSCs) photoanode. The produced nanoparticles were characterized using structural and morphological studies by FTIR, SEM, and XRD experiments, respectively. The results revealed that the net hexagonal crystal structure was achieved with a crystal size of less than 100 nm, good purity, spherical shape, and a suitable dimension for fabricating DSSCs. They exhibit enhanced properties due to the variation in their characteristics such as average size, size distribution, and morphology. The ZnO nanoparticles were used to fabricate the DSSCs by the doctor blade method, and the efficacy of each cell was evaluated using voltage–current measurement. The results were in good agreement with the characteristic curve of the commercialized DSSC. The best performance for the fabricated DSSCs was achieved using green synthesized ZnO nanoparticles, because of the influence of their morphology such as smaller crystal size, more grain boundaries, and bigger surface area. The cell’s solar-to-electricity conversion efficiency, short-circuit current, open-circuit voltage, and fill factor were measured as ∼1.13%, 3.8mA/cm², 620mV, and 54.3%, respectively. The enhanced photovoltaic properties were ascribed to the flower-like morphological structures of the ZnO nanoparticles prepared using the green synthesis method.