Exploring high efficiency S-scheme heterojunction photocatalysts with strong redox ability for removing volatile organic compounds from the air is of great interest and importance.However,how to predict and regulate t...Exploring high efficiency S-scheme heterojunction photocatalysts with strong redox ability for removing volatile organic compounds from the air is of great interest and importance.However,how to predict and regulate the transport of photogenerated carriers in heterojunctions is a great challenge.Here,density functional theory calculations were first used to successfully predict the formation of a CdS quantum dots/InVO_(4)atomic-layer(110)/(110)facet S-scheme heterojunction.Subsequently,a CdS quantum dots/InVO_(4)atomic-layer was synthesized by in-situ loading of CdS quantum dots with(110)facets onto the(110)facets of InVO_(4)atomic-layer.As a result of the deliberately constructed built-in electric field between the adjoining facets,we obtain a remarkably enhanced photocatalytic degradation rate for ethylene.This rate is 13.8 times that of pure CdS and 13.2 times that of pure InVO_(4).In-situ irradiated X-ray photoelectron spectroscopy,photoluminescence and time-resolved photoluminescence measurements were carried out.These experiments validate that the built-in electric field enhanced the dissociation of photoexcited excitons and the separation of free charge carriers,and results in the formation of S-scheme charge transfer pathways.The reaction mechanism of the photocatalytic C_(2)H_(4)oxidation is investigated by in-situ electron paramagnetic resonance.This work provides a mechanistic insight into the construction and optimization of semiconductor heterojunction photocatalysts for application to environmental remediation.展开更多
Development of metal oxide semiconductors-based methane sensors with good response and low power consumption is one of the major challenges to realize the real-time monitoring of methane leakage.In this work,a self-as...Development of metal oxide semiconductors-based methane sensors with good response and low power consumption is one of the major challenges to realize the real-time monitoring of methane leakage.In this work,a self-assembled mulberry-like ZnO/SnO_(2)hierarchical structure is constructed by a two-step hydrothermal method.The resultant sensor works at room temperature with excellent response of~56.1%to 2000 ppm CH_(4)at 55%relative humidity.It is found that the strain induced at the ZnO/SnO_(2)interface greatly enhances the piezoelectric polarization on the ZnO surface and that the band bending results in the accumulation of chemically adsorbed O_(2)^(-)ions close to the interface,leading to significant improvement in the sensing performance of the methane gas sensor at room temperature.展开更多
The use of heterojunctions is a promising solution to the problem of cross-sensitivity in gas sensors.In this work,a carbon monoxide sensor based on the CuO/TiO_(2)heterojunction was designed and fabricated.Due to the...The use of heterojunctions is a promising solution to the problem of cross-sensitivity in gas sensors.In this work,a carbon monoxide sensor based on the CuO/TiO_(2)heterojunction was designed and fabricated.Due to the good adsorption properties of CuO materials to CO,and the heterojunction interface charge transfer,the CuO/TiO_(2)thin film sensor exhibits high sensitivity to CO at room temperature.The response is as high as 10.8–200 ppm CO,about 10 times its response to H_(2).Interference from H_(2)is greatly reduced by optimizing the structure of the CuO/TiO_(2)heterojunction.This reliable detection of carbon monoxide with excellent discrimination against H_(2)is of great significance for the development of CO gas sensors.展开更多
Low electronic conductivity and large volume changes during the(de)lithiation process are the two main challenges for ZnO anode materials used for lithium-ion batteries(LIB).Here,a free-standing,flexible,and binder-fr...Low electronic conductivity and large volume changes during the(de)lithiation process are the two main challenges for ZnO anode materials used for lithium-ion batteries(LIB).Here,a free-standing,flexible,and binder-free LIB electrode composed of ZnO nanorods and carbon cloth(CC)is fabricated.This is then decorated with Ag nanoparticles and finally coated by an amorphous carbon layer to form the hybrid electrode:(C@(Ag&ZnO)).The voids among the nanorods are sufficient to accommodate the volume expansion of the ZnO while the flexible CC,which acts as the current collector,relieves the volume change-induced stress.The Ag nanoparticles are effective in improving the conductivity.This composite electrode shows excellent LIB performance with a stable long cycling life over 500 cycles with a reversible capacity of 1093 mAh g^(-1)at a current density of 200 mA g^(-1).It also shows good rate performance with reversible capacity of 517 mAh g^(-1)under a high-current density of 5000 mA g^(-1).In situ Raman spectroscopy is conducted to investigate the contributions of the amorphous carbon layer to the capacity of the whole electrode and the synergy between the CC and ZnO nanorods.展开更多
Accurate sensing of trace amount of hydrogen without interference from environment is highly desirable in timely detection of possible leakage when using hydrogen as a clean energy source.Humidity in air is usually co...Accurate sensing of trace amount of hydrogen without interference from environment is highly desirable in timely detection of possible leakage when using hydrogen as a clean energy source.Humidity in air is usually considered as the main challenge to the performance of room temperature hydrogen sensors.展开更多
Fullerene(C_(60))nanowires have attracted significant attention in the past two decades due to their outstanding chemical and physical properties,which render the material a wide range of potential applications.Much e...Fullerene(C_(60))nanowires have attracted significant attention in the past two decades due to their outstanding chemical and physical properties,which render the material a wide range of potential applications.Much effort has been devoted to exploring the growth methods,structural and compositional characterizations,and application-related investigations of this novel carbon nanomaterial.Here,we present a review of C_(60)nanowires in which we will first describe the recent development in the material preparations,analytical techniques,crystal structures,chemical compositions,and the investigations of polymerization processes.Afterward,we will discuss the mechanistic studies on the nanowires’growth as the mechanism research is of great importance for their size control,large-scale preparation,and for the exploration of applications in a wide range of fields.Finally,we will discuss the potential applications in several directions,including optical,electrical,mechanical,and biological fields,as well as our perspectives to future developments.展开更多
A trondhjemitic body occurs in the Aoyougou area,the western part of the North Qilian orogen.It is geochemically characterized by high SiO 2,Na 2 O (high Na/K),elevated Sr/Y and (La/Yb) N,positive Sr anomaly,relativel...A trondhjemitic body occurs in the Aoyougou area,the western part of the North Qilian orogen.It is geochemically characterized by high SiO 2,Na 2 O (high Na/K),elevated Sr/Y and (La/Yb) N,positive Sr anomaly,relatively enriched large ion lithophile elements (LILEs) and light rare earth elements (LREEs),and depleted Nb,Ta,Ti,resembling the high-silica adakite.Zircon U-Pb SHRIMP dating yields a weighted mean age of 438±3 Ma.This age is significantly younger than eclogitization ages of 460-490 Ma in the North Qilian orogen,suggesting that formation of the adakite postdates the subduction of oceanic crust in association with closure of the ancient Qilian Ocean.Whole-rock Sr and Nd isotopic analyses give initial ratios of I Sr =0.7044 0.7047 and Nd (t)=3.0 4.1,indicating that they are derived from partial melting of the juvenile oceanic crust.In view of the tectonic evolution of the North Qilian orogen,the high-silica adakite was probably derived from decompression melting of the exhumed eclogite at the depth of ～60 km.展开更多
To suppress shuttling effect and improve electrochemical performance of the sulfur cathode for lithium- sulfur batteries, core-shell structured MoS2 @S spherical cathode has been synthesized through a chemical route u...To suppress shuttling effect and improve electrochemical performance of the sulfur cathode for lithium- sulfur batteries, core-shell structured MoS2 @S spherical cathode has been synthesized through a chemical route using MnC03 as template. The MoS2 shells consist of MoS2 nanosheets. For comparison, MoS2/S cathode has also been synthesized through melting and diffusion of sulfur to commercial MoS2 pow-ders. The electrochemical performance of the MoS2@S and MoS2/S cathodes have been evaluated using cyclic voltammetry, discharge/charge cycling, electrochemical impedance spectroscopy coupled with impedance fitting. The electrochemical performance of the MoS2@S spherical cathode has been much improved compared with that of MoS2/5. The capacity of the MoS2 @S spheres can reach 1185.7 mA h g^-1 at 0.2 C and 955.1 mA h g^-1 at 1 C with initial-cycle coulombic efficiency of 90%. The capacity fading of each cycle is 0.1% during 200 lithiation/delithiation cycles. The MoS2 @S spherical cathode with high cyclic capacity and stability is promising cathode candidate for lithium-sulfur batteries.展开更多
An electrochemical sensor for determination of hydroquinone （HQ） and catechol （CC） was developed using Au nanoparticles （AuNPs） fabricated on reduced graphene oxide/polyimide （PIIRGO） film by electroless depos...An electrochemical sensor for determination of hydroquinone （HQ） and catechol （CC） was developed using Au nanoparticles （AuNPs） fabricated on reduced graphene oxide/polyimide （PIIRGO） film by electroless deposition. The electrochemical behaviors of HQ and CC at PIIRGO-AuNPs electrode were investigated by cyclic voltammetry （CV） and differential pulse voltammetry （DPV）. Under the optimized condition, the current responses at PI/RGO-AuNPs electrode were linear over ranges from 1 to 654 mol/L for HQ and from 2 to 1289 mol/L for CC, with the detection limits of 0.09 and 0.2 mollL, respectively. The proposed electrode exhibited good reproducibility, stability and selectivity. In addition, the proposed electrode was successfully applied in the determination of HQ and CC in tap water and the Yellow River samples.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.21902046,21801071,12174092,U21A20500)Overseas Expertise Introduction Center for Discipline Innovation(D18025)+3 种基金the Natural Science Foundation of Hubei Provincial(Grant No.2018CFB171)Wuhan Science and Technology Bureau(2020010601012163)Science and Technology Research Project of Hubei Provincial Department of Education(No.D20221001)the open foundation of the State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences
文摘Exploring high efficiency S-scheme heterojunction photocatalysts with strong redox ability for removing volatile organic compounds from the air is of great interest and importance.However,how to predict and regulate the transport of photogenerated carriers in heterojunctions is a great challenge.Here,density functional theory calculations were first used to successfully predict the formation of a CdS quantum dots/InVO_(4)atomic-layer(110)/(110)facet S-scheme heterojunction.Subsequently,a CdS quantum dots/InVO_(4)atomic-layer was synthesized by in-situ loading of CdS quantum dots with(110)facets onto the(110)facets of InVO_(4)atomic-layer.As a result of the deliberately constructed built-in electric field between the adjoining facets,we obtain a remarkably enhanced photocatalytic degradation rate for ethylene.This rate is 13.8 times that of pure CdS and 13.2 times that of pure InVO_(4).In-situ irradiated X-ray photoelectron spectroscopy,photoluminescence and time-resolved photoluminescence measurements were carried out.These experiments validate that the built-in electric field enhanced the dissociation of photoexcited excitons and the separation of free charge carriers,and results in the formation of S-scheme charge transfer pathways.The reaction mechanism of the photocatalytic C_(2)H_(4)oxidation is investigated by in-situ electron paramagnetic resonance.This work provides a mechanistic insight into the construction and optimization of semiconductor heterojunction photocatalysts for application to environmental remediation.
基金financially supported by the National Natural Science Foundation of China(No.12174092,21902046,U21A20500)Overseas Expertise Introduction Center for Discipline Innovation(D18025)+1 种基金Hubei Provincial Department of Science and Technology(No.2019CFA079)Wuhan Science and Technology Bureau(2020010601012163)
文摘Development of metal oxide semiconductors-based methane sensors with good response and low power consumption is one of the major challenges to realize the real-time monitoring of methane leakage.In this work,a self-assembled mulberry-like ZnO/SnO_(2)hierarchical structure is constructed by a two-step hydrothermal method.The resultant sensor works at room temperature with excellent response of~56.1%to 2000 ppm CH_(4)at 55%relative humidity.It is found that the strain induced at the ZnO/SnO_(2)interface greatly enhances the piezoelectric polarization on the ZnO surface and that the band bending results in the accumulation of chemically adsorbed O_(2)^(-)ions close to the interface,leading to significant improvement in the sensing performance of the methane gas sensor at room temperature.
基金support from National Natural Science Foundation of China(11874144,12174092,U21A20500)Hubei Provincial Department of Science and Technology(2019CFA079)+1 种基金Wuhan Science and Technology Bureau(2020010601012163)Overseas Expertise Introduction Center for Discipline Innovation(D18025).
文摘The use of heterojunctions is a promising solution to the problem of cross-sensitivity in gas sensors.In this work,a carbon monoxide sensor based on the CuO/TiO_(2)heterojunction was designed and fabricated.Due to the good adsorption properties of CuO materials to CO,and the heterojunction interface charge transfer,the CuO/TiO_(2)thin film sensor exhibits high sensitivity to CO at room temperature.The response is as high as 10.8–200 ppm CO,about 10 times its response to H_(2).Interference from H_(2)is greatly reduced by optimizing the structure of the CuO/TiO_(2)heterojunction.This reliable detection of carbon monoxide with excellent discrimination against H_(2)is of great significance for the development of CO gas sensors.
基金support from National Natural Science Foundation of China(Nos:11874144,12174092 and U21A20500)Hubei Provincial Department of Science and Technology(No.2019CFA079)+1 种基金Wuhan Science and Technology Bureau(2020010601012163)Overseas Expertise Introduction Center for Discipline Innovation(D18025).
文摘Low electronic conductivity and large volume changes during the(de)lithiation process are the two main challenges for ZnO anode materials used for lithium-ion batteries(LIB).Here,a free-standing,flexible,and binder-free LIB electrode composed of ZnO nanorods and carbon cloth(CC)is fabricated.This is then decorated with Ag nanoparticles and finally coated by an amorphous carbon layer to form the hybrid electrode:(C@(Ag&ZnO)).The voids among the nanorods are sufficient to accommodate the volume expansion of the ZnO while the flexible CC,which acts as the current collector,relieves the volume change-induced stress.The Ag nanoparticles are effective in improving the conductivity.This composite electrode shows excellent LIB performance with a stable long cycling life over 500 cycles with a reversible capacity of 1093 mAh g^(-1)at a current density of 200 mA g^(-1).It also shows good rate performance with reversible capacity of 517 mAh g^(-1)under a high-current density of 5000 mA g^(-1).In situ Raman spectroscopy is conducted to investigate the contributions of the amorphous carbon layer to the capacity of the whole electrode and the synergy between the CC and ZnO nanorods.
基金This work is supported in part by the 1000 Talents Program of China,the Zhengz-hou Materials Genome Institute,the National Natural Science Foundation of China(Nos.51001091,111174256,91233101,51602094,11274100)the Fun-damental Research Program from the Ministry of Science and Technology of China(no.2014CB931704).
文摘Accurate sensing of trace amount of hydrogen without interference from environment is highly desirable in timely detection of possible leakage when using hydrogen as a clean energy source.Humidity in air is usually considered as the main challenge to the performance of room temperature hydrogen sensors.
文摘Fullerene(C_(60))nanowires have attracted significant attention in the past two decades due to their outstanding chemical and physical properties,which render the material a wide range of potential applications.Much effort has been devoted to exploring the growth methods,structural and compositional characterizations,and application-related investigations of this novel carbon nanomaterial.Here,we present a review of C_(60)nanowires in which we will first describe the recent development in the material preparations,analytical techniques,crystal structures,chemical compositions,and the investigations of polymerization processes.Afterward,we will discuss the mechanistic studies on the nanowires’growth as the mechanism research is of great importance for their size control,large-scale preparation,and for the exploration of applications in a wide range of fields.Finally,we will discuss the potential applications in several directions,including optical,electrical,mechanical,and biological fields,as well as our perspectives to future developments.
基金supported by the National Basic Research Program of China(2009CB825007)the National Natural Science Foundation of China(40825007and40821002)the Chinese Geological Survey Projects(1212011121258)
文摘A trondhjemitic body occurs in the Aoyougou area,the western part of the North Qilian orogen.It is geochemically characterized by high SiO 2,Na 2 O (high Na/K),elevated Sr/Y and (La/Yb) N,positive Sr anomaly,relatively enriched large ion lithophile elements (LILEs) and light rare earth elements (LREEs),and depleted Nb,Ta,Ti,resembling the high-silica adakite.Zircon U-Pb SHRIMP dating yields a weighted mean age of 438±3 Ma.This age is significantly younger than eclogitization ages of 460-490 Ma in the North Qilian orogen,suggesting that formation of the adakite postdates the subduction of oceanic crust in association with closure of the ancient Qilian Ocean.Whole-rock Sr and Nd isotopic analyses give initial ratios of I Sr =0.7044 0.7047 and Nd (t)=3.0 4.1,indicating that they are derived from partial melting of the juvenile oceanic crust.In view of the tectonic evolution of the North Qilian orogen,the high-silica adakite was probably derived from decompression melting of the exhumed eclogite at the depth of ～60 km.
基金supported by the National Natural Science Foundation of China(Nos.51472083 and 51402101)
文摘To suppress shuttling effect and improve electrochemical performance of the sulfur cathode for lithium- sulfur batteries, core-shell structured MoS2 @S spherical cathode has been synthesized through a chemical route using MnC03 as template. The MoS2 shells consist of MoS2 nanosheets. For comparison, MoS2/S cathode has also been synthesized through melting and diffusion of sulfur to commercial MoS2 pow-ders. The electrochemical performance of the MoS2@S and MoS2/S cathodes have been evaluated using cyclic voltammetry, discharge/charge cycling, electrochemical impedance spectroscopy coupled with impedance fitting. The electrochemical performance of the MoS2@S spherical cathode has been much improved compared with that of MoS2/5. The capacity of the MoS2 @S spheres can reach 1185.7 mA h g^-1 at 0.2 C and 955.1 mA h g^-1 at 1 C with initial-cycle coulombic efficiency of 90%. The capacity fading of each cycle is 0.1% during 200 lithiation/delithiation cycles. The MoS2 @S spherical cathode with high cyclic capacity and stability is promising cathode candidate for lithium-sulfur batteries.
基金Acknowledgement This work was supported by the National Natural Science Foundation of China （Grant No. 51372106）.
文摘An electrochemical sensor for determination of hydroquinone （HQ） and catechol （CC） was developed using Au nanoparticles （AuNPs） fabricated on reduced graphene oxide/polyimide （PIIRGO） film by electroless deposition. The electrochemical behaviors of HQ and CC at PIIRGO-AuNPs electrode were investigated by cyclic voltammetry （CV） and differential pulse voltammetry （DPV）. Under the optimized condition, the current responses at PI/RGO-AuNPs electrode were linear over ranges from 1 to 654 mol/L for HQ and from 2 to 1289 mol/L for CC, with the detection limits of 0.09 and 0.2 mollL, respectively. The proposed electrode exhibited good reproducibility, stability and selectivity. In addition, the proposed electrode was successfully applied in the determination of HQ and CC in tap water and the Yellow River samples.
