The bamboo-like FeVO4 nanocrystallines were synthesized by a two-step method of the microwave hydrothermal-calcination, using Fe (NO3)3·9H2O and NH4VO3 as raw materials. The physical and photophysical properties of the as-prepared photocatalysts were fully characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), UV-vis diffuse reflectance spectra and photoluminescence (PL) analysis. The photocatalytic activities were evaluated by the decolorization of RhB solution under UV and visible light irradiation. The results reveal that the precursor solution concentration is 0.15 mol/L, the molar ratio n (Fe)/n (V) is 1, pH=3.0. The microwave hydrothermal reaction is at 180 °C for 120 min and then calcinated under 550 °C for 3 h so as to obtain the triclinic FeVO4 nanocrystalline. Along [120] and [110], the fore and aft phases of the crystal orientation are bonded self-assembly to grow into the bamboo-like nanocrystalline with the energy gap of 2.42 eV. Under the UV-light irradiation for 240 min, the degradation rate of RhB is up to 91.2%. Adding 0.1 mL H2O2 to the solution, the out-phase photo-fenton reaction occurs and the degradation rate to RhB can reach to 98.8% after 8 h visible-light irradiation.
Bismuth ferrite powders were synthesized by a simple citric acid complexing co-precipitation method at much lower temperature of 600°C. The work studies the calcination temperature and molar ratio of Fe and Bi on the structure and morphology. The as-prepared BiFeO3 powder was characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscope and Fourier transform infrared spectrophotometer. The result shows that the phase pure BiFeO3 powders with cubic morphology were prepared as the calcination temperature was 600°C and molar ratio of Fe and Bi was 1:1. The nanoparticles was uniform with the size of about 200nm.
In this study, the KNbO3, NaNbO3and NaTaO3powders were synthesized by hydrothermal method and the KNN ceramics were prepared by conventional sintering technique. The physical phase constitution and morphology were analyzed by X-ray diffraction and SEM. The KNN ceramics sintering temperature and the influence of Ta5+doping on ceramic properties were explored. The results indicate that the optimal sintering temperature of KNN ceramics is 950°C, and the main phase is orthorhombic structure. After the substitution of Ta5+, the optimal sintering temperature is increased to 975°C. As the increase of doping amount, the piezoelectric properties have been significantly enhanced. The specimen doping 0.08 mol% Ta5+exhibits the enhanced electrical properties (d33=125pC/N, Qm=131, and kp=0.24).
Polycrystalline BiFeO3 multiferroic films were fabricated on Ti substrates by hydrothermal
method from an aqueous Bi (NO3)3•5H2O, FeCl3•6H2O and NaOH solution. The films grow in alkaline
solution at low temperatures of 120°C-240°C for 18 hours. XRD analysis showed that well-developed
crystallines with single perovskite crystal phase were obtained. It was also found that the increase of
reaction temperature and concentration of NaOH were favorable for crystal growth and crystallographic
regularization. The microstructure, thickness and cross-section of the films were characterized by FE
SEM and EDS. Results indicated that dense and homogeneous BiFeO3 thin films could be obtained in an
appropriate hydrothermal condition.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.