This research paper proposes the usage of a simple thermal treatment method to synthesis the pure and Eu3+ doped ZnO/Zn2SiO4 based composites which undergo calcination process at different temperatures. The effect of calcination temperatures on the structural, morphological, and optical properties of ZnO/Zn2SiO4 based composites have been studied. The XRD analysis shows the existence of two major phases which are ZnO and Zn2SiO4 crystals and supported by the finding in the FT-IR. The FESEM micrograph further confirms the existence of both ZnO and Zn2SiO4 crystal phases, with progress in the calcination temperature around 700–800 °C which affects the existence of the necking-like shape particle. Absorption humps discovered through UV-Vis spectroscopy revealed that at the higher calcination temperature effects for higher absorption intensity while absorption bands can be seen at below 400 nm with dropping of absorption bands at 370–375 nm. Two types of band gap can be seen from the energy band gap analysis which occurs from ZnO crystal and Zn2SiO4 crystal progress. It is also discovered that for Eu3+ doped ZnO/Zn2SiO4 composites, the Zn2SiO4 crystal (5.11–4.71 eV) has a higher band gap compared to the ZnO crystal (3.271–4.07 eV). While, for the photoluminescence study, excited at 400 nm, the emission spectra of Eu3+ doped ZnO/Zn2SiO4 revealed higher emission intensity compared to pure ZnO/Zn2SiO4 with higher calcination temperature exhibit higher emission intensity at 615 nm with 700 °C being the optimum temperature. The emission spectra also show that the calcination temperature contributed to enhancing the emission intensity.

A new transparent zinc silicate glass-ceramic was derived from the 55ZnO–5B2O3–40SLS glass system via a controlled heat-treatment method. The precursor glass sample was placed through the heat-treatment process at different temperatures to study the progress in phase transformation, optical performance and emission intensity of the zinc silicate glass-ceramics. For this project, material characterization was measured through several tests using densimeter and linear shrinkage measurement, X-ray diffraction (XRD), Fourier transform infrared reflection (FTIR), ultraviolet–visible (UV–Vis) and photoluminescence (PL) spectroscopy. The density and linear shrinkage measurements show that the density of the particular glass-ceramic samples increases with the progression of heating temperature. The XRD analysis displays the result in which the zinc silicate crystal starts to grow after the sample was treated at 700 °C. In addition, the FTIR spectra indicated that the crystallization of the zinc silicate phase occurred with the appearance of SiO4, ZnO4 and Si-O-Zn bands. UV–visible exhibited the small changes when the value for the optical band gap decreased from 3.867 to 3.423 eV, influenced by the temperature applied to the sample. Furthermore, the PL spectroscopy showed an enhancement of broad green emission at 534 nm upon the increased heat-treatment temperature. Thus, it can be concluded there is the progression of crystal growth as the heat-treatment temperature increased; three emission peaks appeared at 529, 570 and 682 nm for the green, yellow and red emissions, respectively.

This study aims to fabricate low-cost foam glass-ceramic using soda-lime-silica (SLS) glass waste and clamshells (CS) as foaming agent in content between 1 and 12 wt.% by conventional powder processing method. The samples were undergoing sintering process between 700 and 1000?C with holding time of 30 minutes and characterized according to the physical and structural properties. Samples containing 3 wt.% CS treated at 800?C show the greatest size of porosity. As the sintering temperature increased, the samples tend to become less dense. However, for the samples sintered at 900 and 1000?C, the trend of the density changes because of the excess CO2 gases generated during the heat treatment process promotes an increase in internal pressure, which results in the rupture of the pore walls. For linear expansion, for samples with a sintering temperature of 800?C and higher, the increment of the temperature will lead to the decrement of linear expansion (%). As the sintering temperature increases from 700 to 800?C, the water absorption (%) increases. However, the percentage of water absorption decreases with the further increment of sintering temperature. The XRD characterization showed the formation of wollastonite phase (CaSiO3) and further revealed the formation of greater peaks of CaSiO3 at the higher sintering temperatures. The results of compressive mechanical strength between 0.15 and 1.50 MPa indicate that the obtained glass-ceramic foams have potential for building material applications.

Eu 3+ -doped Zn 2 SiO 4 /ZnO phosphor-based composites were prepared using a simple thermal treatment method. The effect of Eu 3+ content on the morphological and photoluminescence performance was examined using XRD, FTIR, FESEM, UV-Vis, and PL measurement. The existence of two crystal phases by the XRD measurement confirmed the development of zincite (ZnO) and zinc silicate (Zn 2 SiO 4 ) crystal phases. Besides, the FTIR spectra and FESEM micrograph support the XRD result by verifying ZnO and Zn 2 SiO 4 phase formation through the existence of their characteristic Zn-O-Si and Zn-O vibration modes with the decrement of SiO 4 broad absorption band as the Eu 3+ concentration increased. Also, UV-Vis absorption spectra presented by the composite samples displayed a broad absorbance that confirmed the addition of Eu 3+ ions in the ZnO/Zn 2 SiO 4 has caused the absorption edge of the curve having red shift. The photoluminescence spectrum showed red shift light emissions at 485 and 615 nm, associating with the Zn 2 SiO 4 crystal phase, in addition to the ZnO crystal phase. From the interesting results achieved, this ZnO/Zn 2 SiO 4 phosphor-based composite material can be a potent candidate in optoelectronic applications.

The impact of sintering duration on willemite-based glass-ceramics (WGC) derived from the ZnO-B2O3-SiO2 host system through a conventional melt-quenching method by incorporating rice husk ash (RHA) as the silica (SiO2) source was comprehensively studied by means of physical, structural, and optical properties. The increment of sintering duration elevated the diffusivity rate resulting in a gradual increment of bulk density and linear shrinkage over sintering time. The XRD patterns affirmed the ?-Zn2SiO4 phase formed after sintering at 700?C for 2 h, followed by ?-Zn2SiO4 crystallization at a higher holding time. FESEM observation revealed that Zn2SiO4 embedded in the glassy solid phase and grew in equiaxed shape crystals as the holding time increased. Absorption spectra revealed the increasing trend in absorption bands with an increase in sintering duration due to the intensification of Zn2SiO4 crystallization thus escalating the green emission. Thus, this WGC will be applied as optically phosphor materials.