It was focused on the applications and developments of microwave hydrothermal synthesis piezoelectric ceramic powder. The microwave hydrothermal vessel was designed and manufactured. The microwave hydrothermal synthe... It was focused on the applications and developments of microwave hydrothermal synthesis piezoelectric ceramic powder. The microwave hydrothermal vessel was designed and manufactured. The microwave hydrothermal synthesis system was established and the PZT piezoelectric ceramic powder was synthesized. XRD and TEM have been used to characterize the products in detail. The diameter of the PZT powder particle is from 40 to 60 nm.展开更多
The in-situ grown of nanostructured MnO2 on activated carbon fiber cloth(ACFC) was obtained with a potassium permanganate solution in the absence of oxidant, reductant or binder addition via a typical microwave hydrot...The in-situ grown of nanostructured MnO2 on activated carbon fiber cloth(ACFC) was obtained with a potassium permanganate solution in the absence of oxidant, reductant or binder addition via a typical microwave hydrothermal synthesis procedure. The carbon fiber cloth serves as a sacrificial reductant and a substrate material to guarantee MnO2 deposition. The results show that the synthesis condition has a great influence on the morphology and structure of MnO2 grown on ACFC.Highly ordered grass-blade-like δ-MnO2/ACFC hybrid nanocomposites were synthesized at 70℃ for 60 min. The grass-blade-like δ-MnO2 are 500 nm in length and 10 nm in depth, and they are well-proportioned grown on the surface of ACFC. The combination of ACFC and MnO2 is rather tight, thus improving the toughness of MnO2. This free-standing, flexible hybrid structure material could be used as a favorable candidate of flexible supercapacitor electrode materials.展开更多
This study employed microwave-assisted hydrothermal method to synthesize Ti-MCM-41,which are mesoporous materials with a high surface area and excellent photocatalytic ability. Fourier transform infrared spectroscopy...This study employed microwave-assisted hydrothermal method to synthesize Ti-MCM-41,which are mesoporous materials with a high surface area and excellent photocatalytic ability. Fourier transform infrared spectroscopy（FTIR）, X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS）, transmission electron microscopy（TEM）, and ultraviolet–visible spectroscopy（UV–Vis） were employed. The XRD findings showed that Ti-MCM-41 exhibited a peak at 2θ of 2.2°, which was attributed to the hexagonal MCM-41 structure. The BET（Brunauer–Emmett–Teller） results agreed with the TEM findings that Ti-MCM-41 has a pore size of about 3–5 nm and a high surface area of 883 m-2/g. FTIR results illustrated the existence of Si–O–Si and Si–O–Ti bonds in Ti-MCM-41. The appearance of Ti2 p peaks in the XPS results confirmed the FTIR findings that the Ti was successfully doped into the MCM-41 structure. Zeta（ζ）-potential results indicated that the iso-electric point（IEP） of Ti-MCM-41 was at about pH 3.02. In this study, the photocatalytic degradation of oxytetracycline（OTC） at different pH was investigated under Hg lamp irradiation（wavelength 365 nm）. The rate constant（K′obs） for OTC degradation was 0.012 min-1at pH 3. Furthermore, TOC（total organic carbon） and high resolution LC–MS（liquid chromatography–mass spectrometry） analyses were conducted to elucidate the possible intermediate products and degradation pathway for OTC. The TOC removal efficiency of OTC degradation was 87.0%, 74.4% and 50.9% at pH 3, 7 and 10, respectively. LC–MS analysis results showed that the degradation products from OTC resulted from the removal of functional groups from the OTC ring.展开更多
Rare-earth stannate（Ln_2Sn_2O_7（Ln = Y, La–Lu）） nanocrystals with an average diameter of 50 nm were prepared through a facile microwave hydrothermal method at 200°C within 60 min. The products were well char...Rare-earth stannate（Ln_2Sn_2O_7（Ln = Y, La–Lu）） nanocrystals with an average diameter of 50 nm were prepared through a facile microwave hydrothermal method at 200°C within 60 min. The products were well characterized. The effect of reaction parameters such as temperature, reaction time, p H value, and alkali source on the preparation was investigated. The results revealed that the p H value plays an important role in the formation process of gadolinium stannate（Gd_2Sn_2O_7） nanoparticles. By contrast, the alkali source had no effect on the phase composition or morphology of the final product. Uniform and sphere-like nanoparticles with an average size of approximately 50 nm were obtained at the p H value of 11.5. A possible formation mechanism was briefly proposed. Gd_2Sn_2O_7：Eu^（3＋） nanoparticles displayed strong orange-red emission. Magnetic measurements revealed that Gd_2Sn_2O_7 nanoparticles were paramagnetic. The other rare-earth stannate Ln_2Sn_2O_7（Ln = Y, La–Lu） nanocrystals were prepared by similar approaches.展开更多
文摘 It was focused on the applications and developments of microwave hydrothermal synthesis piezoelectric ceramic powder. The microwave hydrothermal vessel was designed and manufactured. The microwave hydrothermal synthesis system was established and the PZT piezoelectric ceramic powder was synthesized. XRD and TEM have been used to characterize the products in detail. The diameter of the PZT powder particle is from 40 to 60 nm.
基金supported by the Natural Science Foundation from Shandong Province of China (ZR2012EMM005)China Scholarship Council
文摘The in-situ grown of nanostructured MnO2 on activated carbon fiber cloth(ACFC) was obtained with a potassium permanganate solution in the absence of oxidant, reductant or binder addition via a typical microwave hydrothermal synthesis procedure. The carbon fiber cloth serves as a sacrificial reductant and a substrate material to guarantee MnO2 deposition. The results show that the synthesis condition has a great influence on the morphology and structure of MnO2 grown on ACFC.Highly ordered grass-blade-like δ-MnO2/ACFC hybrid nanocomposites were synthesized at 70℃ for 60 min. The grass-blade-like δ-MnO2 are 500 nm in length and 10 nm in depth, and they are well-proportioned grown on the surface of ACFC. The combination of ACFC and MnO2 is rather tight, thus improving the toughness of MnO2. This free-standing, flexible hybrid structure material could be used as a favorable candidate of flexible supercapacitor electrode materials.
基金financial support provided by the Tunghai University Global Research and Education on Environment and Society (No. 103GREEnS 005-2)
文摘This study employed microwave-assisted hydrothermal method to synthesize Ti-MCM-41,which are mesoporous materials with a high surface area and excellent photocatalytic ability. Fourier transform infrared spectroscopy（FTIR）, X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS）, transmission electron microscopy（TEM）, and ultraviolet–visible spectroscopy（UV–Vis） were employed. The XRD findings showed that Ti-MCM-41 exhibited a peak at 2θ of 2.2°, which was attributed to the hexagonal MCM-41 structure. The BET（Brunauer–Emmett–Teller） results agreed with the TEM findings that Ti-MCM-41 has a pore size of about 3–5 nm and a high surface area of 883 m-2/g. FTIR results illustrated the existence of Si–O–Si and Si–O–Ti bonds in Ti-MCM-41. The appearance of Ti2 p peaks in the XPS results confirmed the FTIR findings that the Ti was successfully doped into the MCM-41 structure. Zeta（ζ）-potential results indicated that the iso-electric point（IEP） of Ti-MCM-41 was at about pH 3.02. In this study, the photocatalytic degradation of oxytetracycline（OTC） at different pH was investigated under Hg lamp irradiation（wavelength 365 nm）. The rate constant（K′obs） for OTC degradation was 0.012 min-1at pH 3. Furthermore, TOC（total organic carbon） and high resolution LC–MS（liquid chromatography–mass spectrometry） analyses were conducted to elucidate the possible intermediate products and degradation pathway for OTC. The TOC removal efficiency of OTC degradation was 87.0%, 74.4% and 50.9% at pH 3, 7 and 10, respectively. LC–MS analysis results showed that the degradation products from OTC resulted from the removal of functional groups from the OTC ring.
基金financially supported by the National Natural Science Foundation of China (Nos. 21641008 and 91622105)the Jiangxi Provincial Department of Science and Technology (Nos. 20161BAB203083 and 20151BDH80049)
文摘Rare-earth stannate（Ln_2Sn_2O_7（Ln = Y, La–Lu）） nanocrystals with an average diameter of 50 nm were prepared through a facile microwave hydrothermal method at 200°C within 60 min. The products were well characterized. The effect of reaction parameters such as temperature, reaction time, p H value, and alkali source on the preparation was investigated. The results revealed that the p H value plays an important role in the formation process of gadolinium stannate（Gd_2Sn_2O_7） nanoparticles. By contrast, the alkali source had no effect on the phase composition or morphology of the final product. Uniform and sphere-like nanoparticles with an average size of approximately 50 nm were obtained at the p H value of 11.5. A possible formation mechanism was briefly proposed. Gd_2Sn_2O_7：Eu^（3＋） nanoparticles displayed strong orange-red emission. Magnetic measurements revealed that Gd_2Sn_2O_7 nanoparticles were paramagnetic. The other rare-earth stannate Ln_2Sn_2O_7（Ln = Y, La–Lu） nanocrystals were prepared by similar approaches.
