Developing low-cost and high-efficiency photocatalysts for hydrogen production from solar water splitting is intriguing but challenging. In this study, unique one-dimensional （1D） multi-node MoS2/CdS hetero-nanowir...Developing low-cost and high-efficiency photocatalysts for hydrogen production from solar water splitting is intriguing but challenging. In this study, unique one-dimensional （1D） multi-node MoS2/CdS hetero-nanowires （NWs） for efficient visible-light photocatalytic H2 evolution are synthesized via a facile hydrothermal method. Flower-like sheaths are assembled from numerous_ defect-rich O-incorporated {0001} MoS2 facet surrounded CdS NW stems are ultrathin nanosheets （NSs）, and {1120}- grown preferentially along the c-axis. Interestingly, the defects in the MoS2 NSs provide additional active S atoms on the exposed edge sites, and the incorporation of O reduces the energy barrier for H2 evolution and increases the electric conductivity of the MoS2 NSs. Moreover, the recombination of photoinduced charge carriers is significantly inhibited by the heterojunction formed between the MoS2 NSs and CdS NWs. Therefore, in the absence of noble metals as co-catalysts, the 1D MoS2 NS/CdS NW hybrids exhibit an excellent H2-generation rate of 10.85 mmol·g^-1·h^-1 and a quantum yield of 22.0% at ,λ = 475 nm, which is far better than those of Pt/CdS NWs, pure MoS2 NSs, and CdS NWs as well as their physical mixtures. Our results contribute to the rational construction of highly reactive nanostructures for various catalytic applications.展开更多
Three novel rare-earth,nitrogen-rich and oxygen heterocyclic supramolecular complexes,namely[Nd(BTF)_(2)(H_(2)O)_(5)]_(n),[Sm(BTF)_(2)(H_(2)O)_(5)]_(n),and[Eu(BTF)_(2)(H_(2)O)_(5)]_(n),were synthesized.A single crysta...Three novel rare-earth,nitrogen-rich and oxygen heterocyclic supramolecular complexes,namely[Nd(BTF)_(2)(H_(2)O)_(5)]_(n),[Sm(BTF)_(2)(H_(2)O)_(5)]_(n),and[Eu(BTF)_(2)(H_(2)O)_(5)]_(n),were synthesized.A single crystal was obtained by the solvent evaporation method,and the structure and coordination mode of metal complexes were determined by single crystal X-ray diffraction.Results show that the supramolecular complexes contain many hydrogen bonds and thus have good thermal stability(T_(dec)>540 K).The thermal decomposition of ammonium perchlorate(AP)catalyzed by the complexes was investigated by differential thermal analysis,which reveals a pre-eminent catalytic effect on AP.The high temperature decomposition peak of AP can be advanced by nearly 90 K at the amount of added complexes of 10 wt%,and the activation energy of AP descent range is from 70 to 150 kJ/mol.The other properties were fully characterized through elemental analysis and Fourier transform infrared spectroscopy.展开更多
A couple of layered Li-rich cathode materials Li1.2Mn0.54Ni0.13Co0.13O2 without any carbon modification are successfully synthesized by solvothermal and hydrothermal methods followed by a calcination process. The samp...A couple of layered Li-rich cathode materials Li1.2Mn0.54Ni0.13Co0.13O2 without any carbon modification are successfully synthesized by solvothermal and hydrothermal methods followed by a calcination process. The sample synthesized by the solvothermal method(S-NCM) possesses more homogenous microstructure, lower cation mixing degree and more oxygen vacancies on the surface, compared to the sample prepared by the hydrothermal method(H-NCM). The S-NCM sample exhibits much better cycling performance, higher discharge capacity and more excellent rate performance than H-NCM. At 0.2 C rate,the S-NCM sample delivers a much higher initial discharge capacity of 292.3 mAh g^-1 and the capacity maintains 235 m Ah g^-1 after 150 cycles(80.4% retention), whereas the corresponding capacity values are only 269.2 and 108.5 m Ah g^-1(40.3% retention) for the H-NCM sample. The S-NCM sample also shows the higher rate performance with discharge capacity of 118.3 mAh g^-1 even at a high rate of 10 C, superior to that(46.5 m Ah g^-1) of the H-NCM sample. The superior electrochemical performance of the S-NCM sample can be ascribed to its well-ordered structure, much larger specific surface area and much more oxygen vacancies located on the surface.展开更多
The electro-catalytic properties can be effectively optimized by designing bimetallic alloy nanoparticles with high-content less-active metal to enhance the competence of more-active noble metal. Herein, a one-pot hyd...The electro-catalytic properties can be effectively optimized by designing bimetallic alloy nanoparticles with high-content less-active metal to enhance the competence of more-active noble metal. Herein, a one-pot hydrothermal approach is demonstrated for the controllable synthesis of Ag-rich Ag_9Pd_1 alloy nanoactiniae with obviously enhanced electro-catalytic activity(2.23 mA cm^(-2) at 0.85 V) and stability for oxygen reduction reaction. In alkaline solution, the ORR onset potential and half-wave potential of the Ag_9Pd_1 alloy nanoactiniae can reach a value of 1.02 V and 0.89 V, respectively, which origin from strong ligand and ensemble effects between Pd element and Ag element. The nanocrystals are uniformly alloyed, displaying a Ag_9Pd_1 combination, as displayed by an assembly of X-ray diffraction(XRD) spectrum,energy dispersive X-ray(EDX) analysis, and cyclic voltammetry(CV). This concept of tuning bimetallic alloy nanocrystals with low concentrations of more precious metal may be a promising approach to be applicable to a wide range of alloy nanocrystals.展开更多
Binary Ce-Zr（CZ）,Pr-Zr（PZ） and ternary Ce-Zr-Pr（CZP） mixed oxides were prepared by an ammonia-aided co-precipitation method,and were aged in a steam/air flow at 1050 °C.X-ray diffraction（XRD）,Raman spectr...Binary Ce-Zr（CZ）,Pr-Zr（PZ） and ternary Ce-Zr-Pr（CZP） mixed oxides were prepared by an ammonia-aided co-precipitation method,and were aged in a steam/air flow at 1050 °C.X-ray diffraction（XRD）,Raman spectra,X-photon spectra（XPS） and CO temperature programmed reduction（TPR） were carried out to characterize the micro-structure and reducibility of catalysts.The oxygen storage capacity（OSC） was evaluated with CO serving as probe gas.The results showed that a pseudo cubic structure was formed for the Zr-rich ceria-zirconia mixed oxides with Pr doping.The insertion of Pr prevented the phase segregation of the mixed oxides during the hydrothermal ageing.The Pr doped samples showed better redox performances in comparison with CZ,and the sample doped with 5 wt.% Pr showed the most remarkably promoted dynamic oxygen storage capacity.This phenomenon was closely related to both the reducibility and oxygen mobility of the mixed oxides.The introduction of praseodymium into ceria-zirconia could accelerate the oxygen migration by increasing the amount of oxygen vacancies,although it was difficult for Pr3＋ ions themselves to participate in the oxygen exchange process.展开更多
Hydrogen can relieve tissue-damaging oxidative stress, inflammation and apoptosis. Injection of hydrogen-rich saline is an effective method for transporting molecular hydrogen. We hypothesized that hydrogen-rich salin...Hydrogen can relieve tissue-damaging oxidative stress, inflammation and apoptosis. Injection of hydrogen-rich saline is an effective method for transporting molecular hydrogen. We hypothesized that hydrogen-rich saline would promote the repair of spinal cord injury induced by Allen＇s method in rats. At 0.5, 1, 2, 4, 8, 12 and 24 hours after injury, then once daily for 2 weeks, 0.25 mL/kg hydrogen-rich saline was infused into the subarachnoid space through a catheter. Results at 24 hours, 48 hours, 1 week and 2 weeks after injury showed that hydrogen-rich saline markedly reduced cell death, inflammatory cell infiltration, serum malondialdehyde content, and caspa se-3 immunoreactivity, elevated serum superoxide dismutase activity and calcitonin gene-related peptide immunoreactivity, and improved motor function in the hindlimb. The present study confirms that hydrogen-rich saline injected within 2 weeks of injury effectively contributes to the repair of spinal cord injury in the acute stage.展开更多
基金Acknowledgements This work was supported by the National Natural Science Foundation of China （Nos. 21431003 and 21521091） and China Ministry of Science and Technology （No. 2016YFA0202801）. We also thank Dr. Lina Zhang and Ms. Xiaohua Gu for their kind help with the TEM measurements.
文摘Developing low-cost and high-efficiency photocatalysts for hydrogen production from solar water splitting is intriguing but challenging. In this study, unique one-dimensional （1D） multi-node MoS2/CdS hetero-nanowires （NWs） for efficient visible-light photocatalytic H2 evolution are synthesized via a facile hydrothermal method. Flower-like sheaths are assembled from numerous_ defect-rich O-incorporated {0001} MoS2 facet surrounded CdS NW stems are ultrathin nanosheets （NSs）, and {1120}- grown preferentially along the c-axis. Interestingly, the defects in the MoS2 NSs provide additional active S atoms on the exposed edge sites, and the incorporation of O reduces the energy barrier for H2 evolution and increases the electric conductivity of the MoS2 NSs. Moreover, the recombination of photoinduced charge carriers is significantly inhibited by the heterojunction formed between the MoS2 NSs and CdS NWs. Therefore, in the absence of noble metals as co-catalysts, the 1D MoS2 NS/CdS NW hybrids exhibit an excellent H2-generation rate of 10.85 mmol·g^-1·h^-1 and a quantum yield of 22.0% at ,λ = 475 nm, which is far better than those of Pt/CdS NWs, pure MoS2 NSs, and CdS NWs as well as their physical mixtures. Our results contribute to the rational construction of highly reactive nanostructures for various catalytic applications.
基金project supported by the National Natural Science Foundation of China(21875192)Outstanding Youth Science and Technology Talents Program of Sichuan(19JCQN0085)the Basic Research Project of Sichuan Province for Science and Technology Development(2019YJ0355)。
文摘Three novel rare-earth,nitrogen-rich and oxygen heterocyclic supramolecular complexes,namely[Nd(BTF)_(2)(H_(2)O)_(5)]_(n),[Sm(BTF)_(2)(H_(2)O)_(5)]_(n),and[Eu(BTF)_(2)(H_(2)O)_(5)]_(n),were synthesized.A single crystal was obtained by the solvent evaporation method,and the structure and coordination mode of metal complexes were determined by single crystal X-ray diffraction.Results show that the supramolecular complexes contain many hydrogen bonds and thus have good thermal stability(T_(dec)>540 K).The thermal decomposition of ammonium perchlorate(AP)catalyzed by the complexes was investigated by differential thermal analysis,which reveals a pre-eminent catalytic effect on AP.The high temperature decomposition peak of AP can be advanced by nearly 90 K at the amount of added complexes of 10 wt%,and the activation energy of AP descent range is from 70 to 150 kJ/mol.The other properties were fully characterized through elemental analysis and Fourier transform infrared spectroscopy.
基金supported financially by the National Key Research and Development Program(No.2017YFA0402800)the National Natural Science Foundation of China(Nos.U1732160and 11504380)
文摘A couple of layered Li-rich cathode materials Li1.2Mn0.54Ni0.13Co0.13O2 without any carbon modification are successfully synthesized by solvothermal and hydrothermal methods followed by a calcination process. The sample synthesized by the solvothermal method(S-NCM) possesses more homogenous microstructure, lower cation mixing degree and more oxygen vacancies on the surface, compared to the sample prepared by the hydrothermal method(H-NCM). The S-NCM sample exhibits much better cycling performance, higher discharge capacity and more excellent rate performance than H-NCM. At 0.2 C rate,the S-NCM sample delivers a much higher initial discharge capacity of 292.3 mAh g^-1 and the capacity maintains 235 m Ah g^-1 after 150 cycles(80.4% retention), whereas the corresponding capacity values are only 269.2 and 108.5 m Ah g^-1(40.3% retention) for the H-NCM sample. The S-NCM sample also shows the higher rate performance with discharge capacity of 118.3 mAh g^-1 even at a high rate of 10 C, superior to that(46.5 m Ah g^-1) of the H-NCM sample. The superior electrochemical performance of the S-NCM sample can be ascribed to its well-ordered structure, much larger specific surface area and much more oxygen vacancies located on the surface.
基金sponsored by the National Natural Science Foundation of China (21576139, 21503111)the Natural Science Foundation of Jiangsu Province (BK20171473)+1 种基金the National and Local Joint Engineering Research Center of Biomedical Functional Materials, Natural Science Foundation of Jiangsu Higher Education Institutions of China (16KJB150020)a project sponsored by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘The electro-catalytic properties can be effectively optimized by designing bimetallic alloy nanoparticles with high-content less-active metal to enhance the competence of more-active noble metal. Herein, a one-pot hydrothermal approach is demonstrated for the controllable synthesis of Ag-rich Ag_9Pd_1 alloy nanoactiniae with obviously enhanced electro-catalytic activity(2.23 mA cm^(-2) at 0.85 V) and stability for oxygen reduction reaction. In alkaline solution, the ORR onset potential and half-wave potential of the Ag_9Pd_1 alloy nanoactiniae can reach a value of 1.02 V and 0.89 V, respectively, which origin from strong ligand and ensemble effects between Pd element and Ag element. The nanocrystals are uniformly alloyed, displaying a Ag_9Pd_1 combination, as displayed by an assembly of X-ray diffraction(XRD) spectrum,energy dispersive X-ray(EDX) analysis, and cyclic voltammetry(CV). This concept of tuning bimetallic alloy nanocrystals with low concentrations of more precious metal may be a promising approach to be applicable to a wide range of alloy nanocrystals.
基金Project supported by the National Natural Science Foundation of China (50972069)the Ministry of Science and Technology, China (2009AA064803)the Chinese Ministry of Industry and Information Technology
文摘Binary Ce-Zr（CZ）,Pr-Zr（PZ） and ternary Ce-Zr-Pr（CZP） mixed oxides were prepared by an ammonia-aided co-precipitation method,and were aged in a steam/air flow at 1050 °C.X-ray diffraction（XRD）,Raman spectra,X-photon spectra（XPS） and CO temperature programmed reduction（TPR） were carried out to characterize the micro-structure and reducibility of catalysts.The oxygen storage capacity（OSC） was evaluated with CO serving as probe gas.The results showed that a pseudo cubic structure was formed for the Zr-rich ceria-zirconia mixed oxides with Pr doping.The insertion of Pr prevented the phase segregation of the mixed oxides during the hydrothermal ageing.The Pr doped samples showed better redox performances in comparison with CZ,and the sample doped with 5 wt.% Pr showed the most remarkably promoted dynamic oxygen storage capacity.This phenomenon was closely related to both the reducibility and oxygen mobility of the mixed oxides.The introduction of praseodymium into ceria-zirconia could accelerate the oxygen migration by increasing the amount of oxygen vacancies,although it was difficult for Pr3＋ ions themselves to participate in the oxygen exchange process.
基金supported by a grant from Hunan Provincial Science and Technology Ministry of China,No.2015JJ6116
文摘Hydrogen can relieve tissue-damaging oxidative stress, inflammation and apoptosis. Injection of hydrogen-rich saline is an effective method for transporting molecular hydrogen. We hypothesized that hydrogen-rich saline would promote the repair of spinal cord injury induced by Allen＇s method in rats. At 0.5, 1, 2, 4, 8, 12 and 24 hours after injury, then once daily for 2 weeks, 0.25 mL/kg hydrogen-rich saline was infused into the subarachnoid space through a catheter. Results at 24 hours, 48 hours, 1 week and 2 weeks after injury showed that hydrogen-rich saline markedly reduced cell death, inflammatory cell infiltration, serum malondialdehyde content, and caspa se-3 immunoreactivity, elevated serum superoxide dismutase activity and calcitonin gene-related peptide immunoreactivity, and improved motor function in the hindlimb. The present study confirms that hydrogen-rich saline injected within 2 weeks of injury effectively contributes to the repair of spinal cord injury in the acute stage.
