The graphene coating was deposited on the surface of Ni foam using the chemical vapor deposition process. A large amount of flower-like ZnCoOmicrospheres with short nanowires were formed on bare Ni foam by hydrotherma...The graphene coating was deposited on the surface of Ni foam using the chemical vapor deposition process. A large amount of flower-like ZnCoOmicrospheres with short nanowires were formed on bare Ni foam by hydrothermal method, while large-scale ZnCoOnanowires arrays homogeneously aligned and separated adequately on Ni foam coated with graphene. This ZnCoOnanowire structure exhibited superior supercapacitors properties. The excellent supercapacitors were mainly attributed to the large specific surface and the porosity on the nanowires which promoted the electrons and ions transportation. In addition, graphene improved conductivity of substrate for current collecting.展开更多
Lithium metal,as the most ideal anode material for high energy density batteries,has been researched for several decades.However,the dendrite formation and large volume change during repetitive lithium plating/strippi...Lithium metal,as the most ideal anode material for high energy density batteries,has been researched for several decades.However,the dendrite formation and large volume change during repetitive lithium plating/stripping lead to a serious safety issue and impede the practical application of lithium metal anode.Herein,a nanoporous Ni foam current collector with high surface area and surface flaws is constructed via a facile oxidation-reduction method.The inherent macropore structure of Ni foam can partly accommodate the volume variation during Li plating/stripping.The well-distributed nanopores on the skeleton of Ni foam can effectively reduce the local current density,regulate the uniform lithium nucleation and deposition with homogenous distribution of Li^(+) flux.Moreover,the surface flaws induce the formation of ring Li structures at initial nucleation/deposition processes and concave Li metal spontaneously formed based on the ring Li structures during cycling,which can direct the even Li plating/stripping.Therefore,highly stable Coulombic efficiency is achieved at 1 mA cm^(-2) for 200 cycles.The symmetrical cell,based on the nanoporous Ni foam current collector,presents long lifespans of 1200 and 700 h respectively at different current densities of 0.5 and 1 mA cm^(-2) without short circuit.In addition,the LiFePO4 full cell,with the Li metal anode based on the nanoporous Ni foam current collector,shows excellent cycling performance at 1 C for 300 cycles and rate performance.展开更多
The growing global demands of safe, low-cost and high working voltage energy storage devices trigger strong interests in novel battery concepts beyond state-of-art lithium-ion battery. Herein, a dualion battery based ...The growing global demands of safe, low-cost and high working voltage energy storage devices trigger strong interests in novel battery concepts beyond state-of-art lithium-ion battery. Herein, a dualion battery based on nanostructured Ni_3S_2/Ni foam@RGO(NSNR) composite anode is developed, utilizing graphite as cathode material and LiPF6-VC-based solvent as electrolyte. The battery operates at high working voltage of 4.2–4.5 V, with superior discharge capacity of ~90 m A h g^(-1) at 100 mA g^(-1), outstanding rate performance, and long-term cycling stability over 500 cycles with discharge capacity retention of ~85.6%. Moreover, the composite simultaneously acts as the anode material and the current collector, and the corrosion phenomenon can be greatly reduced compared to metallic Al anode. Thus, this work represents a significant step forward for practical safe, low-cost and high working voltage dual-ion batteries,showing attractive potential for future energy storage application.展开更多
In this study, we designed and synthesized a novel battery-type electrode featuring three-dimensional(3D) hierarchical ZnO@Ni_xCo_(1-x)(OH)_y core/shell nanowire/nanosheet arrays arranged on Nifoam substrate via a two...In this study, we designed and synthesized a novel battery-type electrode featuring three-dimensional(3D) hierarchical ZnO@Ni_xCo_(1-x)(OH)_y core/shell nanowire/nanosheet arrays arranged on Nifoam substrate via a two-step protocol including a wet chemical process followed by electro-deposition. We then characterized its composition, structure and surface morphology by X-ray diff raction, energy-dispersive X-ray spectrometry(EDS), X-ray photoelectron spectroscopy, scanning electron microscopy(SEM), transmission electron microscopy, EDS elemental mapping. Our electrochemical measurements show that the ZnO@Ni_(0.67)Co_(0.33)(OH)_y electrode material exhibited a noticeably high specific capacity of as much as 255(mA ·h)/g at 1 A/g. Additionally, it demonstrated a superior rate capability, as well as an excellent cycling stability with 81.6% capacity retention over 2000 cycles at 5 A/g. This sample delivered a high energy density of 64 W·h/kg and a power density of 250 W/kg at a current density of 1 A/g. With such remarkable electrochemical properties, we expect the 3D hierarchical hybrid electrode material presented in this work to have promising applications for the next generation of energy storage systems.展开更多
The electrocatalyst NiFeRuO_(x)/NF,comprised of NiFeRuO_(x)nanosheets grown on Ni foam,was synthesized using a hydrothermal process followed by thermal annealing.NiFeRuO_(x)/NF displays high electrocatalytic activity ...The electrocatalyst NiFeRuO_(x)/NF,comprised of NiFeRuO_(x)nanosheets grown on Ni foam,was synthesized using a hydrothermal process followed by thermal annealing.NiFeRuO_(x)/NF displays high electrocatalytic activity and stability for overall alkaline seawater splitting:98 mV@10 mA∙cm^(−2)in hydrogen evolution reaction,318 mV@50 mA∙cm^(−2)in oxygen evolution reaction,and a cell voltage of 1.53 V@10 mA∙cm^(−2),as well as 20 h of durability.A solar-driven system containing such a bifunctional NiFeRuO_(x)/NF has an almost 100%Faradaic efficiency.The NiFeRuO_(x)coating around Ni foam is an anti-corrosion layer and also a critical factor for enhancement of bifunctional performances.展开更多
Photocatalytic fuel cell (PFC) holds great potential for the sustainable production of electricity and degradation of organic pollutants for solving global energy and environmental problems.However,the efficient photo...Photocatalytic fuel cell (PFC) holds great potential for the sustainable production of electricity and degradation of organic pollutants for solving global energy and environmental problems.However,the efficient photodegradation of organic dyes and antibiotic drugs,such as ciprofloxacin (CIP) and methylene blue(MB),remains challenging.Aiming at improving the separation efficiency of hole and electron for electricity generation in the PFC system,TiO_(2)-NPs@NF-x photoanode was fabricated by a cost-effective and laborsaving hydrothermal approach.The as-fabricated photoanode demonstrated abundant active sites,enhanced light harvesting capacity and photogenerated charge carrier separation.At a CIP-HCl concentration of 10 mg/L and p H value of about 7,85%of CIP-HCl can be efficiently removed after 3 h irradiation by 300 W Xe lamp.TiO_(2)-NPs@NF-20 photoelectrode based PFC system exhibited an impressed ability to simultaneously degrade ciprofloxacin and generate electricity under light irradiation with an open circuit voltage of 1.021 V,short circuit current density and maximum power density of 2.4 mA/cm^(2),0.357 mW/cm^(2),respectively.This work provided a cost-effective method for the treatment of organic waste and generation of electrical power.展开更多
Pd modified electrodes possess problems such as easy agglomeration and low electrolytic ability,and the use of manganese dioxide(MnO_(2)) to facilitate Pd reduction of organic pollutants is just started.However,there ...Pd modified electrodes possess problems such as easy agglomeration and low electrolytic ability,and the use of manganese dioxide(MnO_(2)) to facilitate Pd reduction of organic pollutants is just started.However,there is still a limited understanding of how to match the Pd load and MnO_(2) to realize optimal dechlorination efficiency at minimum cost.Here,a Pd/MnO_(2)/Ni foam cathode was successfully fabricated and applied for the efficient electrochemical dechlorination of 2,4,6-trichlorophenol(2,4,6-TCP).The optimal electrocatalytic hydrodechlorination(ECH)performance with 2,4,6-TCP dechlorination efficiency(92.58%in 180 min)was obtained when the concentration of PdCl_(2) precipitation was 1 mmol/L,the deposition time of MnO_(2) was 300 s and cathode potential was-0.8 V.Performance influenced by the exogenous factors(e.g.,initial pH and coexisted ions)were further investigated.It was found that the neutral pH was the most favorable for ECH and a reduction in dechlorination efficiency(6%~47.6%)was observed in presence of 5 mmol/L of NO_(2)^(-),NO_(3)^(-),S^(2-)or SO_(3)^(2-).Cyclic voltammetry(CV)and quenching experiments verified the existence of three hydrogen species on Pd surface,including adsorbed atomic hydrogen(H^(*)_(ads)),absorbed atomic hydrogen(H^(*)_(abs)),and molecular hydrogen(H_(2)).And the introduction of MnO_(2)promoted the generation of atomic H^(*).Only adsorbed atomic hydrogen(H^(*)_(ads)) was confirmed that it truly facilitated the ECH process.Besides H^(*)_(ads) induced reduction,the direct reduction by cathode electrons also participated in the 2,4,6-TCP dechlorination process.Pd/MnO_(2)/Ni foam cathode shows excellent dechlorination performance,fine stability and recyclable potential,which provides strategies for the effective degradation of persistent halogenated organic pollutants in groundwater.展开更多
An electrocatalyst of nickel phosphide (Ni2P) nanorod arrays vertically grown on Ni foam composite (NNFC) was prepared successfully using NaHzPO2 as phosphorus source by means of a facile method of in situ phospho...An electrocatalyst of nickel phosphide (Ni2P) nanorod arrays vertically grown on Ni foam composite (NNFC) was prepared successfully using NaHzPO2 as phosphorus source by means of a facile method of in situ phospho- rization of Ni foam. The as-prepared NNFC exhibits excellent HER performance with an onset overpotential of 100 mV, a small Tafel slope of only 55 mV/dec, and a low overpotential involving 200 mV at a current density of 10 mA·cm^-2. Furthermore, the electrocatalyst was also demonstrated to possess high stability with a neglectable de- crease in activity even after durability test for 25 h.展开更多
NiCo-phosphates can deliver high specific capacitances and high electrochemical activities as pseudocapacitive electrode material for supercapacitors.In this study,The NiCo-phosphates@reduced graphene oxide(NCPO@rGO)c...NiCo-phosphates can deliver high specific capacitances and high electrochemical activities as pseudocapacitive electrode material for supercapacitors.In this study,The NiCo-phosphates@reduced graphene oxide(NCPO@rGO)composite is directly loaded on Ni foam by a simple one-step hydrothermal process.The conductive rGO sheets provides continuous electron pathways between NCPO flowers and Ni foam,allowing active electrochemical reactions throughout the whole electrode.This can solve the difficulty of low active material utility and small areal capacitances in the Ni foam-supported electrodes.At the same time,the rGO sheets creates large amount of mesopores within the electrode,which can ensure a highly open structure for electrolyte attachment and ion transport.Because of the positive effect of rGO in improving charge transfe r,the NiCo-phosphates can be fully involved in the electrochemical reactions with high utility,ensuring high specific capacitances(1416.7 F g^(-1)at 1 A g^(-1))and high-rate performances.Specially,the areal capacitance of the NCPO@rGO electrode can reach as large as 3.69 F cm^(-2)at 1 A g^(-1),which is among the highest ones in Ni foam supported electrodes.An asymmetric supercapacitor is then fabricated by NCPO@rGO as the positive material with attractive energy densities and power densities,further proving its excellent electrochemical performance.展开更多
Herein, we reported the synthesis of well-defined Co_3O_4 nanoarrays(NAs) supported on a monolithic three-dimensional macroporous nickel(Ni) foam substrate for use in highefficiency CO oxidation. The monolithic Co_3O_...Herein, we reported the synthesis of well-defined Co_3O_4 nanoarrays(NAs) supported on a monolithic three-dimensional macroporous nickel(Ni) foam substrate for use in highefficiency CO oxidation. The monolithic Co_3O_4 NAs catalysts were obtained through a generic hydrothermal synthesis route with subsequent calcination. By controlling the reaction time,solvent polarity and deposition agent, these Co_3O_4 NAs catalysts exhibited various novel morphologies(single or hybrid arrays), whose physicochemical properties were further characterized by using several analytical techniques. Based on the catalytic and characterization analyses, it was found that the Co_3O_4 NAs-6 catalyst with nanobrush and nanomace arrays displayed enhanced catalytic activity for CO oxidation, achieving an efficient 100% CO oxidation conversion at a gas hourly space velocity(GHSV) 10,000 hr^(-1) and 150°C with longterm stability. Compared with the other Co_3O_4 NAs catalysts, it had the highest abundance of surface-adsorbed oxygen species, excellent low-temperature reducibility and was rich in surface-active sites(Co^(3+)/Co^(2+)= 1.26).展开更多
Electrochemical dechlorination of chloroform in neutral aqueous solution was investigated using palladium-loaded electrodes at ambient temperature. Palladium/foam-nickel (Pd/foam-Ni) and palladium/polymeric pyrrole ...Electrochemical dechlorination of chloroform in neutral aqueous solution was investigated using palladium-loaded electrodes at ambient temperature. Palladium/foam-nickel (Pd/foam-Ni) and palladium/polymeric pyrrole film/foam-nickel (Pd/PPy/foam-Ni) composite electrodes which provided catalytic surface for reductive dechlorination of chloroform in aqueous solution were prepared using an electrodepositing method. Scanning electron microscope (SEM) micrographs showed that polymeric pyrrole film modified the electrode-surface characteristics and resulted in the uniform dispersion of needle-shaped palladium particles on foam-Ni supporting electrode. The experimental results of dechlorination indicated that the removal efficiency of chloroform and current efficiency in neutral aqueous solution on Pd/PPy/foam-Ni electrode could be up to 36.8% and 33.0% at dechlorination current of 0.1 mA and dechlorination time of 180 min, which is much higher than that of Pd/foam-Ni electrode.展开更多
文摘The graphene coating was deposited on the surface of Ni foam using the chemical vapor deposition process. A large amount of flower-like ZnCoOmicrospheres with short nanowires were formed on bare Ni foam by hydrothermal method, while large-scale ZnCoOnanowires arrays homogeneously aligned and separated adequately on Ni foam coated with graphene. This ZnCoOnanowire structure exhibited superior supercapacitors properties. The excellent supercapacitors were mainly attributed to the large specific surface and the porosity on the nanowires which promoted the electrons and ions transportation. In addition, graphene improved conductivity of substrate for current collecting.
基金the National Natural Science Foundation of China(No.51761135123)the National Key Research&Development Program(2016YFB0303903,2016YFE0201600)。
文摘Lithium metal,as the most ideal anode material for high energy density batteries,has been researched for several decades.However,the dendrite formation and large volume change during repetitive lithium plating/stripping lead to a serious safety issue and impede the practical application of lithium metal anode.Herein,a nanoporous Ni foam current collector with high surface area and surface flaws is constructed via a facile oxidation-reduction method.The inherent macropore structure of Ni foam can partly accommodate the volume variation during Li plating/stripping.The well-distributed nanopores on the skeleton of Ni foam can effectively reduce the local current density,regulate the uniform lithium nucleation and deposition with homogenous distribution of Li^(+) flux.Moreover,the surface flaws induce the formation of ring Li structures at initial nucleation/deposition processes and concave Li metal spontaneously formed based on the ring Li structures during cycling,which can direct the even Li plating/stripping.Therefore,highly stable Coulombic efficiency is achieved at 1 mA cm^(-2) for 200 cycles.The symmetrical cell,based on the nanoporous Ni foam current collector,presents long lifespans of 1200 and 700 h respectively at different current densities of 0.5 and 1 mA cm^(-2) without short circuit.In addition,the LiFePO4 full cell,with the Li metal anode based on the nanoporous Ni foam current collector,shows excellent cycling performance at 1 C for 300 cycles and rate performance.
基金supported by the National Natural Science Foundation of China (No. 51725401)the Fundamental Research Funds for the Central Universities (FRF-TP-15-002C1 and FRF-TP17-002C2)
文摘The growing global demands of safe, low-cost and high working voltage energy storage devices trigger strong interests in novel battery concepts beyond state-of-art lithium-ion battery. Herein, a dualion battery based on nanostructured Ni_3S_2/Ni foam@RGO(NSNR) composite anode is developed, utilizing graphite as cathode material and LiPF6-VC-based solvent as electrolyte. The battery operates at high working voltage of 4.2–4.5 V, with superior discharge capacity of ~90 m A h g^(-1) at 100 mA g^(-1), outstanding rate performance, and long-term cycling stability over 500 cycles with discharge capacity retention of ~85.6%. Moreover, the composite simultaneously acts as the anode material and the current collector, and the corrosion phenomenon can be greatly reduced compared to metallic Al anode. Thus, this work represents a significant step forward for practical safe, low-cost and high working voltage dual-ion batteries,showing attractive potential for future energy storage application.
基金supported by the National Basic Research Program of China ("973" Program, No. 2012CB720302)the National Key Research and Development Program of China (No 2016YFF0102503)
文摘In this study, we designed and synthesized a novel battery-type electrode featuring three-dimensional(3D) hierarchical ZnO@Ni_xCo_(1-x)(OH)_y core/shell nanowire/nanosheet arrays arranged on Nifoam substrate via a two-step protocol including a wet chemical process followed by electro-deposition. We then characterized its composition, structure and surface morphology by X-ray diff raction, energy-dispersive X-ray spectrometry(EDS), X-ray photoelectron spectroscopy, scanning electron microscopy(SEM), transmission electron microscopy, EDS elemental mapping. Our electrochemical measurements show that the ZnO@Ni_(0.67)Co_(0.33)(OH)_y electrode material exhibited a noticeably high specific capacity of as much as 255(mA ·h)/g at 1 A/g. Additionally, it demonstrated a superior rate capability, as well as an excellent cycling stability with 81.6% capacity retention over 2000 cycles at 5 A/g. This sample delivered a high energy density of 64 W·h/kg and a power density of 250 W/kg at a current density of 1 A/g. With such remarkable electrochemical properties, we expect the 3D hierarchical hybrid electrode material presented in this work to have promising applications for the next generation of energy storage systems.
基金National Key R&D Program of China(Grant Nos.2022YFB3805600 and 2022YFB3805604)South Africa’s National Research Foundation through the SARChI Chair in Materials Electrochemistry and Energy Technologies(Grant No.132739)+5 种基金National Natural Science Foundation of China(Grant No.22293020)National 111 project(Grant No.B20002)Program for Innovative Research Team in University of Ministry of Education of China(Grant No.IRT_15R52)Sino-German Centre’s COVID-19 Related Bilateral Collaborative Project(Grant No.C-0046)Guangdong Basic and Applied Basic Research Foundation(Grant No.2022A1515010137)Shenzhen Science and Technology Program(Grant Nos.GJHZ20210705143204014,JCYJ20210324142010029,and KCXFZ20211020170006010).
文摘The electrocatalyst NiFeRuO_(x)/NF,comprised of NiFeRuO_(x)nanosheets grown on Ni foam,was synthesized using a hydrothermal process followed by thermal annealing.NiFeRuO_(x)/NF displays high electrocatalytic activity and stability for overall alkaline seawater splitting:98 mV@10 mA∙cm^(−2)in hydrogen evolution reaction,318 mV@50 mA∙cm^(−2)in oxygen evolution reaction,and a cell voltage of 1.53 V@10 mA∙cm^(−2),as well as 20 h of durability.A solar-driven system containing such a bifunctional NiFeRuO_(x)/NF has an almost 100%Faradaic efficiency.The NiFeRuO_(x)coating around Ni foam is an anti-corrosion layer and also a critical factor for enhancement of bifunctional performances.
基金funded by the National Science and Technology Major Project for Water Pollution Control and Treatment (No. 2018ZX07110-008)National Natural Science Foundation of China (No. 21777065)+1 种基金Basic Scientific Re-search Business Expense Project of Beijing University of Civil Engineering and Architecture (No. X18005)the 2021 BUCEA Post Graduate Innovation Project。
文摘Photocatalytic fuel cell (PFC) holds great potential for the sustainable production of electricity and degradation of organic pollutants for solving global energy and environmental problems.However,the efficient photodegradation of organic dyes and antibiotic drugs,such as ciprofloxacin (CIP) and methylene blue(MB),remains challenging.Aiming at improving the separation efficiency of hole and electron for electricity generation in the PFC system,TiO_(2)-NPs@NF-x photoanode was fabricated by a cost-effective and laborsaving hydrothermal approach.The as-fabricated photoanode demonstrated abundant active sites,enhanced light harvesting capacity and photogenerated charge carrier separation.At a CIP-HCl concentration of 10 mg/L and p H value of about 7,85%of CIP-HCl can be efficiently removed after 3 h irradiation by 300 W Xe lamp.TiO_(2)-NPs@NF-20 photoelectrode based PFC system exhibited an impressed ability to simultaneously degrade ciprofloxacin and generate electricity under light irradiation with an open circuit voltage of 1.021 V,short circuit current density and maximum power density of 2.4 mA/cm^(2),0.357 mW/cm^(2),respectively.This work provided a cost-effective method for the treatment of organic waste and generation of electrical power.
基金supported by the NSFC-JSPS joint research program(No.51961145202)the Natural Science Foundation of Heilongjiang Province,China(No.C2018035)。
文摘Pd modified electrodes possess problems such as easy agglomeration and low electrolytic ability,and the use of manganese dioxide(MnO_(2)) to facilitate Pd reduction of organic pollutants is just started.However,there is still a limited understanding of how to match the Pd load and MnO_(2) to realize optimal dechlorination efficiency at minimum cost.Here,a Pd/MnO_(2)/Ni foam cathode was successfully fabricated and applied for the efficient electrochemical dechlorination of 2,4,6-trichlorophenol(2,4,6-TCP).The optimal electrocatalytic hydrodechlorination(ECH)performance with 2,4,6-TCP dechlorination efficiency(92.58%in 180 min)was obtained when the concentration of PdCl_(2) precipitation was 1 mmol/L,the deposition time of MnO_(2) was 300 s and cathode potential was-0.8 V.Performance influenced by the exogenous factors(e.g.,initial pH and coexisted ions)were further investigated.It was found that the neutral pH was the most favorable for ECH and a reduction in dechlorination efficiency(6%~47.6%)was observed in presence of 5 mmol/L of NO_(2)^(-),NO_(3)^(-),S^(2-)or SO_(3)^(2-).Cyclic voltammetry(CV)and quenching experiments verified the existence of three hydrogen species on Pd surface,including adsorbed atomic hydrogen(H^(*)_(ads)),absorbed atomic hydrogen(H^(*)_(abs)),and molecular hydrogen(H_(2)).And the introduction of MnO_(2)promoted the generation of atomic H^(*).Only adsorbed atomic hydrogen(H^(*)_(ads)) was confirmed that it truly facilitated the ECH process.Besides H^(*)_(ads) induced reduction,the direct reduction by cathode electrons also participated in the 2,4,6-TCP dechlorination process.Pd/MnO_(2)/Ni foam cathode shows excellent dechlorination performance,fine stability and recyclable potential,which provides strategies for the effective degradation of persistent halogenated organic pollutants in groundwater.
文摘An electrocatalyst of nickel phosphide (Ni2P) nanorod arrays vertically grown on Ni foam composite (NNFC) was prepared successfully using NaHzPO2 as phosphorus source by means of a facile method of in situ phospho- rization of Ni foam. The as-prepared NNFC exhibits excellent HER performance with an onset overpotential of 100 mV, a small Tafel slope of only 55 mV/dec, and a low overpotential involving 200 mV at a current density of 10 mA·cm^-2. Furthermore, the electrocatalyst was also demonstrated to possess high stability with a neglectable de- crease in activity even after durability test for 25 h.
基金supported by the Fundamental Research Funds for the Central Universities of China(2652018291 and 2652018318)。
文摘NiCo-phosphates can deliver high specific capacitances and high electrochemical activities as pseudocapacitive electrode material for supercapacitors.In this study,The NiCo-phosphates@reduced graphene oxide(NCPO@rGO)composite is directly loaded on Ni foam by a simple one-step hydrothermal process.The conductive rGO sheets provides continuous electron pathways between NCPO flowers and Ni foam,allowing active electrochemical reactions throughout the whole electrode.This can solve the difficulty of low active material utility and small areal capacitances in the Ni foam-supported electrodes.At the same time,the rGO sheets creates large amount of mesopores within the electrode,which can ensure a highly open structure for electrolyte attachment and ion transport.Because of the positive effect of rGO in improving charge transfe r,the NiCo-phosphates can be fully involved in the electrochemical reactions with high utility,ensuring high specific capacitances(1416.7 F g^(-1)at 1 A g^(-1))and high-rate performances.Specially,the areal capacitance of the NCPO@rGO electrode can reach as large as 3.69 F cm^(-2)at 1 A g^(-1),which is among the highest ones in Ni foam supported electrodes.An asymmetric supercapacitor is then fabricated by NCPO@rGO as the positive material with attractive energy densities and power densities,further proving its excellent electrochemical performance.
基金supported by Science and Technology Planning Project of Guangdong Province China (No.2015B0202236002)the National Natural Science Foundation of China (Nos.21401200,51108187,51672273,B5151050)+2 种基金the National Key R & D Plan (No.2017YFC0211503)the Open Research Fund of State Key Laboratory of Multi-phase Complex Systems (No.MPCS-2017-D-06)the Guangdong Natural Science Foundation (No.2016A030311003)
文摘Herein, we reported the synthesis of well-defined Co_3O_4 nanoarrays(NAs) supported on a monolithic three-dimensional macroporous nickel(Ni) foam substrate for use in highefficiency CO oxidation. The monolithic Co_3O_4 NAs catalysts were obtained through a generic hydrothermal synthesis route with subsequent calcination. By controlling the reaction time,solvent polarity and deposition agent, these Co_3O_4 NAs catalysts exhibited various novel morphologies(single or hybrid arrays), whose physicochemical properties were further characterized by using several analytical techniques. Based on the catalytic and characterization analyses, it was found that the Co_3O_4 NAs-6 catalyst with nanobrush and nanomace arrays displayed enhanced catalytic activity for CO oxidation, achieving an efficient 100% CO oxidation conversion at a gas hourly space velocity(GHSV) 10,000 hr^(-1) and 150°C with longterm stability. Compared with the other Co_3O_4 NAs catalysts, it had the highest abundance of surface-adsorbed oxygen species, excellent low-temperature reducibility and was rich in surface-active sites(Co^(3+)/Co^(2+)= 1.26).
文摘Electrochemical dechlorination of chloroform in neutral aqueous solution was investigated using palladium-loaded electrodes at ambient temperature. Palladium/foam-nickel (Pd/foam-Ni) and palladium/polymeric pyrrole film/foam-nickel (Pd/PPy/foam-Ni) composite electrodes which provided catalytic surface for reductive dechlorination of chloroform in aqueous solution were prepared using an electrodepositing method. Scanning electron microscope (SEM) micrographs showed that polymeric pyrrole film modified the electrode-surface characteristics and resulted in the uniform dispersion of needle-shaped palladium particles on foam-Ni supporting electrode. The experimental results of dechlorination indicated that the removal efficiency of chloroform and current efficiency in neutral aqueous solution on Pd/PPy/foam-Ni electrode could be up to 36.8% and 33.0% at dechlorination current of 0.1 mA and dechlorination time of 180 min, which is much higher than that of Pd/foam-Ni electrode.