2-D nanosheet Cu2O doped CuO coating poly m-phenylenediamine and melamine/graphene/carbon fibers composite(CuxO/MPM/GFs)was firstly fabricated by compound electrochemical method.CuxO/MPM/GFs was successfully used to t...2-D nanosheet Cu2O doped CuO coating poly m-phenylenediamine and melamine/graphene/carbon fibers composite(CuxO/MPM/GFs)was firstly fabricated by compound electrochemical method.CuxO/MPM/GFs was successfully used to the recovery of iodide(I-)from salt water by lower potential-aided sorption and desorption processes.The potential-aided recovery of I-at CuxO/MPM/GFs was characterized by FE-SEM,XRD,IR,Raman,XPS,UV-vis and electrochemical techniques in detail.The maximal adsorption capacity of 86.82 mg·g^-1 could be obtained with a pseudo-second-order model at 0.8 V for 210 min in pH 5.0,0.1 mol·L^-1 NaCl,and the process accompanied the generation of CuI,CuO and I5-.The I-could be quickly desorbed from the electrode with a transfer of CuI to Cu2O by cycle voltammetry from-1.0 to 0.5 V for 90 cycles in pH 9.0,0.1 mol·L^-1 KNO3.Thus,CuxO/MPM/GFs was renewable in the continuous electrochemical-adsorption-desorption processes.展开更多
Soils of the Chinese Loess Plateau(CLP)contain substantial amounts of soil inorganic carbon(SIC),as well as recent and ancient soil organic carbon(SOC).With the advent of the Anthropocene,human perturbation,including ...Soils of the Chinese Loess Plateau(CLP)contain substantial amounts of soil inorganic carbon(SIC),as well as recent and ancient soil organic carbon(SOC).With the advent of the Anthropocene,human perturbation,including excavation,has increased soil CO_(2) emission from the huge loess carbon pool.This study aims to determine the potential of loess CO_(2) emission induced by excavation.Soil CO_(2) were continuously monitored for seven years on a newly-excavated profile in the central CLP and the stable C isotope compositions of soil CO_(2) and SOC were used to identify their sources.The results showed that the soil CO_(2) concentrations ranged from 830μL·L^(-1) to 11190μL·L^(-1) with an annually reducing trend after excavation,indicating that the human excavation can induce CO_(2) production in loess profile.Theδ^(13) C of CO_(2) ranged from–21.27‰to–19.22‰(mean:–20.11‰),with positive deviation from top to bottom.The range of δ^(13)CSOC was–24.0‰to–21.1‰with an average of–23.1‰.Theδ^(13) C-CO_(2) in this study has a positive relationship with the reversed CO_(2) concentration,and it is calculated that 80.22%of the soil CO_(2) in this profile is from the microbial decomposition of SOC and 19.78%from the degasification during carbonate precipitation.We conclude that the human excavation can significantly enhance the decomposition of the ancient OC in loess during the first two years after perturbation,producing and releasing soil CO_(2) to atmosphere.展开更多
A novel fluorescent probe for H_2PO_4^- was designed and fabricated based on the carbon dots/Fe^（3＋） composite. The carbon dots were synthesized by an established one-pot hydrothermal method and characterized by tr...A novel fluorescent probe for H_2PO_4^- was designed and fabricated based on the carbon dots/Fe^（3＋） composite. The carbon dots were synthesized by an established one-pot hydrothermal method and characterized by transmission electron microscope, X-ray diffractometer, UV-Vis absorption spectrometer and fluorescence spectrophotometer. The carbon dots/Fe^（3＋） composite was obtained by aqueous mixing of carbon dots and FeCl_3, and its fluorescence property was characterized by fluorescence spectrophotometer. The fluorescence of carbon dots was quenched by aqueous Fe^（3＋） cations, resulting in the low fluorescence intensity of the carbon dots/Fe^（3＋） composite. On the other hand, H_2PO_4^- reduced the concentration of Fe^（3＋） by chemical reaction and enhanced the fluorescence of the carbon dots/Fe^（3＋） composite. The Stern-Volmer equation was introduced to describe the relation between the relative fluorescence intensity of the carbon dots/Fe^（3＋） composite and the concentration of H_2PO_4^-, and a fine linearity（R2=0.997） was found in the range of H_2PO_4^- concentration of 0.4-12 m M.展开更多
Self-aggregation and sluggish transport kinetics of cathode materials would usually lead to the poor electrochemical performance for aqueous zinc-ion batteries(AZIBs).In this work,we report the construction of C@VO_(2...Self-aggregation and sluggish transport kinetics of cathode materials would usually lead to the poor electrochemical performance for aqueous zinc-ion batteries(AZIBs).In this work,we report the construction of C@VO_(2) composite via anti-aggregation growth and hierarchical porous carbon encapsulation.Both of the morphology of composite and pore structure of carbon layer can be regulated by tuning the adding amount of glucose.When acting as cathode applied for AZIBs,the C@VO_(2)-3:3 composite can deliver a high capacity of 281 m Ah g^(-1) at 0.2 A g^(-1).Moreover,such cathode also exhibits a remarkably rate capability and cyclic stability,which can release a specific capacity of 195 m Ah g^(-1) at 5 A g^(-1) with the capacity retention of 95.4%after 1000 cycles.Besides that,the evolution including the crystal structure,valence state and transport kinetics upon cycling were also deeply investigated.In conclusion,benefited from the synergistic effect of anti-aggregation morphology and hierarchical porous carbon encapsulation,the building of such C@VO_(2) composite can be highly expected to enhance the ion accessible site,boost the transport kinetics and thus performing a superior storage performance.Such design concept can be applied for other kinds of electrode materials and accelerating the development of highperformance AZIBs.展开更多
Mesoporous Ti O2/Carbon beads have been prepared via a facile impregnation-carbonization approach, in which a porous anion-exchange resin and K2 Ti O(C2O4)2were used as hard carbon and titanium source, respectively.Ch...Mesoporous Ti O2/Carbon beads have been prepared via a facile impregnation-carbonization approach, in which a porous anion-exchange resin and K2 Ti O(C2O4)2were used as hard carbon and titanium source, respectively.Characterization results reveal that the self-assembled composites have disordered mesostructure, uniform mesopores,large pore volumes, and high surface areas. The mesopore walls are composed of amorphous carbon, well-dispersed and confined anatase or rutile nanoparticles. Some anatase phase of Ti O2 was transformed to rutile phase via an increase of carbonization temperature or repeated impregnation of the resin with Ti O(C2O4)22-species. X-ray photoelectron spectroscopy, carbon, hydrogen, and nitrogen element analysis, and thermal gravity analysis results indicate the doping of carbon into the Ti O2 lattice and strong interaction between carbon and Ti O2 nanoparticles. A synergy effect by carbon and Ti O2 in the composites has been discussed herein on the degradation of methyl orange under visible light. The dye removal process involves adsorption of the dye from water by the mesopores in the composites, followed by photodegradation on the separated dye-loaded catalysts. Mesopores allow full access of the dye molecules to the surface of Ti O2 nanoparticles.Importantly, the bead format of such composite enables their straightforward separation from the reaction mixture in their application as a liquid-phase heterogeneous photodegradation catalyst.展开更多
A high active novel TiO2/AC composite photocatalyst was prepared and used for phenol degradation. It was much more active than P-25 and exhibiting good decantability, less deactivation after several runs and less sens...A high active novel TiO2/AC composite photocatalyst was prepared and used for phenol degradation. It was much more active than P-25 and exhibiting good decantability, less deactivation after several runs and less sensitive to pH change. Diffuse reflectance spectra （DRS） revealed that the electronic change in TiO2 did not occur by the addition of AC. Results of SEM and XRD suggested that better TiO2 distribution can be achieved when optimal AC content was adopted. The performance of the prepared TiO2/5AC catalyst revealed great practical potential in wastewater treatment field.展开更多
基金supported by the National Natural Science Foundation of China(U1407110)Anhui Province Key Research and Development Plan(JZ2018AKKG0332)。
文摘2-D nanosheet Cu2O doped CuO coating poly m-phenylenediamine and melamine/graphene/carbon fibers composite(CuxO/MPM/GFs)was firstly fabricated by compound electrochemical method.CuxO/MPM/GFs was successfully used to the recovery of iodide(I-)from salt water by lower potential-aided sorption and desorption processes.The potential-aided recovery of I-at CuxO/MPM/GFs was characterized by FE-SEM,XRD,IR,Raman,XPS,UV-vis and electrochemical techniques in detail.The maximal adsorption capacity of 86.82 mg·g^-1 could be obtained with a pseudo-second-order model at 0.8 V for 210 min in pH 5.0,0.1 mol·L^-1 NaCl,and the process accompanied the generation of CuI,CuO and I5-.The I-could be quickly desorbed from the electrode with a transfer of CuI to Cu2O by cycle voltammetry from-1.0 to 0.5 V for 90 cycles in pH 9.0,0.1 mol·L^-1 KNO3.Thus,CuxO/MPM/GFs was renewable in the continuous electrochemical-adsorption-desorption processes.
基金funded by National Natural Science Foundation of China(Grant No.41877398)the Basic Science Research Fund from the Institute of Chinese Academy of Geological Sciences(Grant No.SK201911)the Belt and Road Fund on Water and Sustainability(U2019NKMS01)。
文摘Soils of the Chinese Loess Plateau(CLP)contain substantial amounts of soil inorganic carbon(SIC),as well as recent and ancient soil organic carbon(SOC).With the advent of the Anthropocene,human perturbation,including excavation,has increased soil CO_(2) emission from the huge loess carbon pool.This study aims to determine the potential of loess CO_(2) emission induced by excavation.Soil CO_(2) were continuously monitored for seven years on a newly-excavated profile in the central CLP and the stable C isotope compositions of soil CO_(2) and SOC were used to identify their sources.The results showed that the soil CO_(2) concentrations ranged from 830μL·L^(-1) to 11190μL·L^(-1) with an annually reducing trend after excavation,indicating that the human excavation can induce CO_(2) production in loess profile.Theδ^(13) C of CO_(2) ranged from–21.27‰to–19.22‰(mean:–20.11‰),with positive deviation from top to bottom.The range of δ^(13)CSOC was–24.0‰to–21.1‰with an average of–23.1‰.Theδ^(13) C-CO_(2) in this study has a positive relationship with the reversed CO_(2) concentration,and it is calculated that 80.22%of the soil CO_(2) in this profile is from the microbial decomposition of SOC and 19.78%from the degasification during carbonate precipitation.We conclude that the human excavation can significantly enhance the decomposition of the ancient OC in loess during the first two years after perturbation,producing and releasing soil CO_(2) to atmosphere.
基金Funded by the National Natural Science Foundation of China(Nos.61575150 and 61377092)the Natural Science Foundation of Hubei Province(N0.2014CFB831)
文摘A novel fluorescent probe for H_2PO_4^- was designed and fabricated based on the carbon dots/Fe^（3＋） composite. The carbon dots were synthesized by an established one-pot hydrothermal method and characterized by transmission electron microscope, X-ray diffractometer, UV-Vis absorption spectrometer and fluorescence spectrophotometer. The carbon dots/Fe^（3＋） composite was obtained by aqueous mixing of carbon dots and FeCl_3, and its fluorescence property was characterized by fluorescence spectrophotometer. The fluorescence of carbon dots was quenched by aqueous Fe^（3＋） cations, resulting in the low fluorescence intensity of the carbon dots/Fe^（3＋） composite. On the other hand, H_2PO_4^- reduced the concentration of Fe^（3＋） by chemical reaction and enhanced the fluorescence of the carbon dots/Fe^（3＋） composite. The Stern-Volmer equation was introduced to describe the relation between the relative fluorescence intensity of the carbon dots/Fe^（3＋） composite and the concentration of H_2PO_4^-, and a fine linearity（R2=0.997） was found in the range of H_2PO_4^- concentration of 0.4-12 m M.
基金financially supported by the National Natural Science Foundation of China(Nos.51774203)the Shenzhen Science and Technology Program(Nos.JCYJ20200109105801725)。
文摘Self-aggregation and sluggish transport kinetics of cathode materials would usually lead to the poor electrochemical performance for aqueous zinc-ion batteries(AZIBs).In this work,we report the construction of C@VO_(2) composite via anti-aggregation growth and hierarchical porous carbon encapsulation.Both of the morphology of composite and pore structure of carbon layer can be regulated by tuning the adding amount of glucose.When acting as cathode applied for AZIBs,the C@VO_(2)-3:3 composite can deliver a high capacity of 281 m Ah g^(-1) at 0.2 A g^(-1).Moreover,such cathode also exhibits a remarkably rate capability and cyclic stability,which can release a specific capacity of 195 m Ah g^(-1) at 5 A g^(-1) with the capacity retention of 95.4%after 1000 cycles.Besides that,the evolution including the crystal structure,valence state and transport kinetics upon cycling were also deeply investigated.In conclusion,benefited from the synergistic effect of anti-aggregation morphology and hierarchical porous carbon encapsulation,the building of such C@VO_(2) composite can be highly expected to enhance the ion accessible site,boost the transport kinetics and thus performing a superior storage performance.Such design concept can be applied for other kinds of electrode materials and accelerating the development of highperformance AZIBs.
基金supported by Natural Science Foundation of China(21303031,21353004,51472062)Natural Science Foundation of Heilongjiang Province of China(B201010)+2 种基金Fundamental Research Funds for the Central Universities(HIT.IBRSEM.201326)Program for Science&Technology Innovation Talent in Harbin(2013RFQXJ004,2007RFXXG018)China Postdoctoral Science Foundation(2012T50334,20100480991)
文摘Mesoporous Ti O2/Carbon beads have been prepared via a facile impregnation-carbonization approach, in which a porous anion-exchange resin and K2 Ti O(C2O4)2were used as hard carbon and titanium source, respectively.Characterization results reveal that the self-assembled composites have disordered mesostructure, uniform mesopores,large pore volumes, and high surface areas. The mesopore walls are composed of amorphous carbon, well-dispersed and confined anatase or rutile nanoparticles. Some anatase phase of Ti O2 was transformed to rutile phase via an increase of carbonization temperature or repeated impregnation of the resin with Ti O(C2O4)22-species. X-ray photoelectron spectroscopy, carbon, hydrogen, and nitrogen element analysis, and thermal gravity analysis results indicate the doping of carbon into the Ti O2 lattice and strong interaction between carbon and Ti O2 nanoparticles. A synergy effect by carbon and Ti O2 in the composites has been discussed herein on the degradation of methyl orange under visible light. The dye removal process involves adsorption of the dye from water by the mesopores in the composites, followed by photodegradation on the separated dye-loaded catalysts. Mesopores allow full access of the dye molecules to the surface of Ti O2 nanoparticles.Importantly, the bead format of such composite enables their straightforward separation from the reaction mixture in their application as a liquid-phase heterogeneous photodegradation catalyst.
基金This project was financially supported by Specialized Research Fund for the Doctoral Program of Higher Education （No. 20050225006）the National Natural Science Foundation of China （No. 30400339）.
文摘A high active novel TiO2/AC composite photocatalyst was prepared and used for phenol degradation. It was much more active than P-25 and exhibiting good decantability, less deactivation after several runs and less sensitive to pH change. Diffuse reflectance spectra （DRS） revealed that the electronic change in TiO2 did not occur by the addition of AC. Results of SEM and XRD suggested that better TiO2 distribution can be achieved when optimal AC content was adopted. The performance of the prepared TiO2/5AC catalyst revealed great practical potential in wastewater treatment field.
