Lithium metal is one of the most promising anode materials for next-generation electrochemical energy storage due to low electrochemical potential and high specific capacity.However,large volume change and uncontrolla...Lithium metal is one of the most promising anode materials for next-generation electrochemical energy storage due to low electrochemical potential and high specific capacity.However,large volume change and uncontrollable formation of lithium dendrite during cycling severely hinder the practical application of rechargeable Li metal batteries.Herein,we report a hierarchically porous Cu covered with lithiophilic CuxO(HPCu-CuxO) via femtosecond laser strategy in about 2 min as current collector for highperformance Li metal batteries.With precisely tunable pore volume and depth as well as lithiophilic CuxO interphase,the HPCu-CuxO not only guides homogeneous Li nucleation,resulting in a smooth and dendrite-free lithium surface,but also provides space to alleviate the volume expansion of Li metal anode,achieving excellent structure stability.Consequently,highly stable Coulombic efficiency and ultralow overpotential of 15 mV even up to 1000 h were achieved at the current density of 1 mA cm^(-2).Moreover,the resultant Li@HPCu-CuxO//LiFePO_(4) full battery delivered outstanding cycle stability and rate capability.These results offer a pathway toward high-energy-density and safe rechargeable Li metal batteries.展开更多
Carboxyl graphene modified CuxO/Cu electrode was fabricated. The bare copper electrode was firstly anodic polarized in 1.0 mol/L NaOH solution in order to get CuxO nanoparticles, then the carboxyl graphene （CG） was ...Carboxyl graphene modified CuxO/Cu electrode was fabricated. The bare copper electrode was firstly anodic polarized in 1.0 mol/L NaOH solution in order to get CuxO nanoparticles, then the carboxyl graphene （CG） was electrodeposited on the CuxO/Cu electrode by cyclic potential sweeping. The electrocatalytic oxidation behaviors of calcium folinate （CF） at the graphene modified CuxO/Cu electrode were investigated by cyclic voltammetry. A positive scan polarization reverse catalytic voltammetry was used to obtain the pure catalytic oxidation current. The graphene modified CuxO/Cu electrode was served as the electrochemical sensor of CF, a highly sensitivity of 22.0μA.（μmol/μL）^-1cm^-2 was achieved, and the current response was linear with increasing CF concentration in the range of 2.0×10^-7 mol/L to 2.0×10^-5 mol/L, which crossed three orders of magnitude, and the detection limit was found 7.6×10^-5 mol/L （S/N=3）. In addition, the proposed sensor was successfully applied in determination of CF in drug sample.展开更多
Copper oxide has aroused great concern in energy storage fields due to its properties of high theoretical capacitance,low cost and mild toxicity.However,its wide application still remains challenges owing to its poor ...Copper oxide has aroused great concern in energy storage fields due to its properties of high theoretical capacitance,low cost and mild toxicity.However,its wide application still remains challenges owing to its poor electrical conductivity and unstable cycling life.Binder-free foam electrodes possess abundant porous structures and high specific surface area,which could get good contact with electrolyte.Herein,we demonstrate Ag nanoparticles decorated CuxO nanowires grown spontaneously on copper foam(CF)electrode for asymmetric supercapacitor.The skeleton structure of CF provides large amounts of active sites for the growth of CuxO nanowires.Moreover,Ag nanoparticles further decrease the internal resistance and enhance the electrochemical performance.Ag/CuxO/CF-40 electrode presents a high area specific capacitance of 1192 mF cm^(-2)at 2 mA cm^(-2)and the influence of surface capacitance-dominated process and diffusion-controlled process are discussed in detail.Besides,the energy density of the as-prepared asymmetric supercapacitor(ASC)reaches 46.32 mWh cm^(-2)at a power density of 3.00 mW cm^(-2).A 2V LED is lighted successfully by two ASC in series.This work provides a new strategy to prepare low internal resistance and binder-free flexible Ag/CuxO/CF electrode,which demonstrates a good potential application in flexible supercapacitors or other wearable electronic devices.展开更多
The CuxO/TiO_(2)nanotubes arrays are fabricated in two stages.Firstly,TiO_(2)-NTs are grown by the Ti-foil anodization process and then annealed for 2h at 500℃.Subsequently,CuxO thin film was deposited with different...The CuxO/TiO_(2)nanotubes arrays are fabricated in two stages.Firstly,TiO_(2)-NTs are grown by the Ti-foil anodization process and then annealed for 2h at 500℃.Subsequently,CuxO thin film was deposited with different deposition times on the nanotubes by electrochemical cathodic reaction,then heated twice,once at 200℃in the air and then at 300℃ in the closed furnace for 2 h,respectively.Pure-TNT and Cu_(x)O/TNTs heterostructure are characterized by XRD,FE-SEM,EDX,Hall effect,and as a gas sensor.Results show that the gas sensor(CuO_(x=1)/TiO_(2)for NO_(2)and H_(2)gases)prepared at the time(1 min)is higher than the pure TiO_(2)-NTs and also higher than Cu_(x=2)O/TiO_(2)which were synthesized at various times 3,5,7,and 10 mins.展开更多
Bandgap engineering by doping and co‐catalyst loading are two primary approaches to designing efficient photocatalysts by promoting visible‐light absorption and charge separation,respectively.Shifting of the TiO2con...Bandgap engineering by doping and co‐catalyst loading are two primary approaches to designing efficient photocatalysts by promoting visible‐light absorption and charge separation,respectively.Shifting of the TiO2conduction band edge is frequently applied to increase visible‐light absorption but also lowers the reductive properties of photo‐excited electrons.Herein,we report a visible‐light‐driven photocatalyst based on valance band edge control induced by oxygen excess defects and modification with a CuxO electron transfer co‐catalyst.The CuxO grafted oxygen‐rich TiO2microspheres were prepared by ultrasonic spray pyrolysis of the peroxotitanate precursor followed by a wet chemical impregnated treatment.We found that oxygen excess defects in TiO2shifted the valence band maximum upward and improved the visible‐light absorption.The CuxO grafted onto the surface acted as a co‐catalyst that efficiently reduced oxygen molecules to active intermediates(i.e.,O2??radial and H2O2),thus consuming the photo‐generated electrons.Consequently,the CuxO grafted oxygen‐rich TiO2microspheres achieved a photocatalytic activity respectively8.6,13.0and11.0as times high as those of oxygen‐rich TiO2,normal TiO2and CuxO grafted TiO2,for degradation of gaseous acetaldehyde under visible‐light irradiation.Our results suggest that high visible‐light photocatalytic efficiency can be achieved by combining oxygen excess defects to improve visible‐light absorption together with a CuxO electron transfer co‐catalyst.These findings provide a new approach to developing efficient heterojunction photocatalysts.展开更多
Zno.95-xCoo.05CuxO （atomic ratio, x = 0-8%） thin films are fabricated on Si（lll） substrate by reactive magnetron sputtering method. Detailed characterizations indicate that the doped Cu ions substitute the Zn2＋ i...Zno.95-xCoo.05CuxO （atomic ratio, x = 0-8%） thin films are fabricated on Si（lll） substrate by reactive magnetron sputtering method. Detailed characterizations indicate that the doped Cu ions substitute the Zn2＋ ions in ZnO lattice. The doped Cu ions are in ＋1 and ＋2 mixture valent state. The ferromagnetism of the Zno.95-xCoo.o5CuxO film increases gradually with the increase of the Cu＋ ion concentration till x = 6%, but decreases for higher Cu concentration. Experimental results indicate that the increase of ferromagnetism is not owing to the magnetic contribution of Cu＋ ions themselves, but owing to the enhancement of magnetic interaction between Co2＋ ions, which suggests that p-type doping of Cu＋ ions plays an important role in mediating the ferromagnetic coupling between Co ions.展开更多
Electrochemical nitrite(NO_(2)^(−))reduction offers a sustainable route for ammonia(NH_(3))synthesis while simultaneously removing contaminants in wastewater.However,its efficiency is often limited by low catalytic ef...Electrochemical nitrite(NO_(2)^(−))reduction offers a sustainable route for ammonia(NH_(3))synthesis while simultaneously removing contaminants in wastewater.However,its efficiency is often limited by low catalytic efficiency and the competitive hydrogen evolution reaction at low NO_(2)^(−)concentrations.Herein,we report an intermittent pulsed electrolysis(IPE)strategy using copper oxide(Cu_(x)O)nanowires,which significantly enhances the NH3 yield rate and Faradaic efficiency(FE)at lower reactant concentrations.In situ experiments and theoretical calculations reveal that alternating between open-circuit and cathodic potentials modulates the copper oxidation states,stabilizing the catalytically active cuprous oxide(Cu_(2)O).Consequently,the IPE approach provides an outstanding NH3 yield rate of 115.10 mg·h^(−1)·cm^(−2)and FE of 91.14%in the presence of 25 mM NO_(2)^(−),markedly outperforming conventional constant potential electrolysis.展开更多
A series of CuxO self-assembled mesoporous microspheres （SMMs）, with different and controlled mor- phology （virus-like, urchin-like, spherical）, were synthesized by facile liquid phase approach. The morphology of ...A series of CuxO self-assembled mesoporous microspheres （SMMs）, with different and controlled mor- phology （virus-like, urchin-like, spherical）, were synthesized by facile liquid phase approach. The morphology of the as- prepared CuxO SMMs was evolved from spherical to virus-like shape by controlling the ratio of DI water in solution. It can also realize the transformation from loose assembly to dense assembly by extending the reaction time. These CuxO SMMs exhibited good response to NO2 gas at room temperature, benefiting from their 3D self-assembly structure. Among these the resulting virus-like CuxO SNMMs-based sensor exhibits largely enhanced response to 1 ppm NO2 gas at room temperature. The enhanced response of the virus-like Cn2O SMMs-based sensor can be ascribed to the high surface area, hier- archical 3D nanostructures, micropores for effective gas diffusion, the heterojunctions formed between CuO and Cu2O, and the existence of abundant surface oxygen vacancies.展开更多
基金financially supported by the Fundamental Research Funds of the Central Universities(no.531107051048)the support from the Hunan Key Laboratory of Two-Dimensional Materials(No.801200005)。
文摘Lithium metal is one of the most promising anode materials for next-generation electrochemical energy storage due to low electrochemical potential and high specific capacity.However,large volume change and uncontrollable formation of lithium dendrite during cycling severely hinder the practical application of rechargeable Li metal batteries.Herein,we report a hierarchically porous Cu covered with lithiophilic CuxO(HPCu-CuxO) via femtosecond laser strategy in about 2 min as current collector for highperformance Li metal batteries.With precisely tunable pore volume and depth as well as lithiophilic CuxO interphase,the HPCu-CuxO not only guides homogeneous Li nucleation,resulting in a smooth and dendrite-free lithium surface,but also provides space to alleviate the volume expansion of Li metal anode,achieving excellent structure stability.Consequently,highly stable Coulombic efficiency and ultralow overpotential of 15 mV even up to 1000 h were achieved at the current density of 1 mA cm^(-2).Moreover,the resultant Li@HPCu-CuxO//LiFePO_(4) full battery delivered outstanding cycle stability and rate capability.These results offer a pathway toward high-energy-density and safe rechargeable Li metal batteries.
文摘Carboxyl graphene modified CuxO/Cu electrode was fabricated. The bare copper electrode was firstly anodic polarized in 1.0 mol/L NaOH solution in order to get CuxO nanoparticles, then the carboxyl graphene （CG） was electrodeposited on the CuxO/Cu electrode by cyclic potential sweeping. The electrocatalytic oxidation behaviors of calcium folinate （CF） at the graphene modified CuxO/Cu electrode were investigated by cyclic voltammetry. A positive scan polarization reverse catalytic voltammetry was used to obtain the pure catalytic oxidation current. The graphene modified CuxO/Cu electrode was served as the electrochemical sensor of CF, a highly sensitivity of 22.0μA.（μmol/μL）^-1cm^-2 was achieved, and the current response was linear with increasing CF concentration in the range of 2.0×10^-7 mol/L to 2.0×10^-5 mol/L, which crossed three orders of magnitude, and the detection limit was found 7.6×10^-5 mol/L （S/N=3）. In addition, the proposed sensor was successfully applied in determination of CF in drug sample.
基金supported by Key R&D Program of Zhenjiang(GY2018016).
文摘Copper oxide has aroused great concern in energy storage fields due to its properties of high theoretical capacitance,low cost and mild toxicity.However,its wide application still remains challenges owing to its poor electrical conductivity and unstable cycling life.Binder-free foam electrodes possess abundant porous structures and high specific surface area,which could get good contact with electrolyte.Herein,we demonstrate Ag nanoparticles decorated CuxO nanowires grown spontaneously on copper foam(CF)electrode for asymmetric supercapacitor.The skeleton structure of CF provides large amounts of active sites for the growth of CuxO nanowires.Moreover,Ag nanoparticles further decrease the internal resistance and enhance the electrochemical performance.Ag/CuxO/CF-40 electrode presents a high area specific capacitance of 1192 mF cm^(-2)at 2 mA cm^(-2)and the influence of surface capacitance-dominated process and diffusion-controlled process are discussed in detail.Besides,the energy density of the as-prepared asymmetric supercapacitor(ASC)reaches 46.32 mWh cm^(-2)at a power density of 3.00 mW cm^(-2).A 2V LED is lighted successfully by two ASC in series.This work provides a new strategy to prepare low internal resistance and binder-free flexible Ag/CuxO/CF electrode,which demonstrates a good potential application in flexible supercapacitors or other wearable electronic devices.
基金supported by the University of Al-Qadisiyah,Iraq,and Imam Abdulrahman bin Faisal University,Saudi Arabia.
文摘The CuxO/TiO_(2)nanotubes arrays are fabricated in two stages.Firstly,TiO_(2)-NTs are grown by the Ti-foil anodization process and then annealed for 2h at 500℃.Subsequently,CuxO thin film was deposited with different deposition times on the nanotubes by electrochemical cathodic reaction,then heated twice,once at 200℃in the air and then at 300℃ in the closed furnace for 2 h,respectively.Pure-TNT and Cu_(x)O/TNTs heterostructure are characterized by XRD,FE-SEM,EDX,Hall effect,and as a gas sensor.Results show that the gas sensor(CuO_(x=1)/TiO_(2)for NO_(2)and H_(2)gases)prepared at the time(1 min)is higher than the pure TiO_(2)-NTs and also higher than Cu_(x=2)O/TiO_(2)which were synthesized at various times 3,5,7,and 10 mins.
基金supported by the National Natural Science Foundation of China(51072032,51372036,51702235)~~
文摘Bandgap engineering by doping and co‐catalyst loading are two primary approaches to designing efficient photocatalysts by promoting visible‐light absorption and charge separation,respectively.Shifting of the TiO2conduction band edge is frequently applied to increase visible‐light absorption but also lowers the reductive properties of photo‐excited electrons.Herein,we report a visible‐light‐driven photocatalyst based on valance band edge control induced by oxygen excess defects and modification with a CuxO electron transfer co‐catalyst.The CuxO grafted oxygen‐rich TiO2microspheres were prepared by ultrasonic spray pyrolysis of the peroxotitanate precursor followed by a wet chemical impregnated treatment.We found that oxygen excess defects in TiO2shifted the valence band maximum upward and improved the visible‐light absorption.The CuxO grafted onto the surface acted as a co‐catalyst that efficiently reduced oxygen molecules to active intermediates(i.e.,O2??radial and H2O2),thus consuming the photo‐generated electrons.Consequently,the CuxO grafted oxygen‐rich TiO2microspheres achieved a photocatalytic activity respectively8.6,13.0and11.0as times high as those of oxygen‐rich TiO2,normal TiO2and CuxO grafted TiO2,for degradation of gaseous acetaldehyde under visible‐light irradiation.Our results suggest that high visible‐light photocatalytic efficiency can be achieved by combining oxygen excess defects to improve visible‐light absorption together with a CuxO electron transfer co‐catalyst.These findings provide a new approach to developing efficient heterojunction photocatalysts.
基金the Basic Scientific Research Business Expenses of the Central UniversityOpen Project of Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education,Lanzhou University (No.LZUMMM2012001)the Natural Science Foundation of Anhui Province(No.1208085ME84)
文摘Zno.95-xCoo.05CuxO （atomic ratio, x = 0-8%） thin films are fabricated on Si（lll） substrate by reactive magnetron sputtering method. Detailed characterizations indicate that the doped Cu ions substitute the Zn2＋ ions in ZnO lattice. The doped Cu ions are in ＋1 and ＋2 mixture valent state. The ferromagnetism of the Zno.95-xCoo.o5CuxO film increases gradually with the increase of the Cu＋ ion concentration till x = 6%, but decreases for higher Cu concentration. Experimental results indicate that the increase of ferromagnetism is not owing to the magnetic contribution of Cu＋ ions themselves, but owing to the enhancement of magnetic interaction between Co2＋ ions, which suggests that p-type doping of Cu＋ ions plays an important role in mediating the ferromagnetic coupling between Co ions.
基金supported in part by the National Key R&D Program of China(No.2024YFA1509400)the National Natural Science Foundation of China(No.52302094)Natural Science Foundation of Jiangxi,China(No.20232ACB203002).
文摘Electrochemical nitrite(NO_(2)^(−))reduction offers a sustainable route for ammonia(NH_(3))synthesis while simultaneously removing contaminants in wastewater.However,its efficiency is often limited by low catalytic efficiency and the competitive hydrogen evolution reaction at low NO_(2)^(−)concentrations.Herein,we report an intermittent pulsed electrolysis(IPE)strategy using copper oxide(Cu_(x)O)nanowires,which significantly enhances the NH3 yield rate and Faradaic efficiency(FE)at lower reactant concentrations.In situ experiments and theoretical calculations reveal that alternating between open-circuit and cathodic potentials modulates the copper oxidation states,stabilizing the catalytically active cuprous oxide(Cu_(2)O).Consequently,the IPE approach provides an outstanding NH3 yield rate of 115.10 mg·h^(−1)·cm^(−2)and FE of 91.14%in the presence of 25 mM NO_(2)^(−),markedly outperforming conventional constant potential electrolysis.
基金supported by the National Natural Science Foundation(51501010,91323301,51631001,51372025 and21643003)
文摘A series of CuxO self-assembled mesoporous microspheres （SMMs）, with different and controlled mor- phology （virus-like, urchin-like, spherical）, were synthesized by facile liquid phase approach. The morphology of the as- prepared CuxO SMMs was evolved from spherical to virus-like shape by controlling the ratio of DI water in solution. It can also realize the transformation from loose assembly to dense assembly by extending the reaction time. These CuxO SMMs exhibited good response to NO2 gas at room temperature, benefiting from their 3D self-assembly structure. Among these the resulting virus-like CuxO SNMMs-based sensor exhibits largely enhanced response to 1 ppm NO2 gas at room temperature. The enhanced response of the virus-like Cn2O SMMs-based sensor can be ascribed to the high surface area, hier- archical 3D nanostructures, micropores for effective gas diffusion, the heterojunctions formed between CuO and Cu2O, and the existence of abundant surface oxygen vacancies.
