The environmental concerns resulting from coal-fired power generation that produces large amounts of CO_(2)and fly ash are of great interest.To mitigate,this study aims to develop a novel carbonated CO_(2)-fly ash-bas...The environmental concerns resulting from coal-fired power generation that produces large amounts of CO_(2)and fly ash are of great interest.To mitigate,this study aims to develop a novel carbonated CO_(2)-fly ash-based backfill(CFBF)material under ambient conditions.The performance of CFBF was investigated for different fly ash-cement ratios and compared with non-CO_(2)reacted samples.The fresh CFBF slurry conformed to the Herschel-Bulkley model with shear thinning characteristics.After carbonation,the yield stress of the fresh slurry increased significantly by lowering fly ash ratio due to gel formation.The setting times were accelerated,resulting in approximately 40.6%of increased early strength.The final strength decreased when incorporating a lower fly ash ratio(50%and 60%),which was related to the existing heterogeneous pores caused by rapid fluid loss.The strength increased with fly ash content above 70%because additional C-S(A)-H and silica gels were characterized to precipitate on the grain surface,so the binding between particles increased.The C-S(A)-H gel was developed through the pozzolanic reaction,where CaCO_(3)was the prerequisite calcium source obtained in the CO_(2)-fly ash reaction.Furthermore,the maximum CO_(2)uptake efficiency was 1.39 mg-CO_(2)/g-CFBF.The CFBF material is feasible to co-dispose CO_(2)and fly ash in the mine goaf as negative carbon backfill materials,and simultaneously mitigates the strata movement and water lost in post-subsurface mining.展开更多
Electrochemical nitrogen reduction reaction(e-NRR)under ambient conditions is an emerging strategy to tackle the hydrogen-and energy-intensive operations for traditional Haber-Bosch process in industrial ammonia(NH_(3...Electrochemical nitrogen reduction reaction(e-NRR)under ambient conditions is an emerging strategy to tackle the hydrogen-and energy-intensive operations for traditional Haber-Bosch process in industrial ammonia(NH_(3))synthesis.However,the e-NRR performance is currently impeded by the inherent inertness of N_(2) molecules,the extremely slow kinetics and the overwhelming competition from the hydrogen evolution reaction(HER),all of which cause unsatisfied yield and ammonia selectivity(Faradaic efficiency,FE).Defect and interface engineering are capable of achieving novel physical and chemical properties as well as superior synergistic effects for various electrocatalysts.In this review,we first provide a general introduction to the NRR mechanism.We then focus on the recent progress in defect and interface engineering and summarize how defect and interface can be rationally designed and functioned in NRR catalysts.Particularly,the origin of superior NRR catalytic activity by applying these approaches was discussed from both theoretical and experimental perspectives.Finally,the remaining challenges and future perspectives in this emerging area are highlighted.It is expected that this review will shed some light on designing NRR electrocatalysts with excellent activity,selectivity and stability.展开更多
Electrocatalytic N2 reduction to NH3 under ambient conditions is an eco-friendly and sustainable alternative to the traditional Haber-Bosch process. However, inhibited by the high activation barrier of N2, this proces...Electrocatalytic N2 reduction to NH3 under ambient conditions is an eco-friendly and sustainable alternative to the traditional Haber-Bosch process. However, inhibited by the high activation barrier of N2, this process needs efficient electrocatalysts to adsorb and activate the N2, enabling the N2 reduction reaction(NRR). Herein, we report that porous LaFeO3 nanofiber with oxygen vacancies acts as an efficient NRR electrocatalyst with abundant active sites to enhance the adsorption and activation of N2. When tested in 0.1 M HCl, such electrocatalyst achieves a high Faradaic efficiency of 8.77% and a large NH3 yield rate of 18.59 μg h–1 mgcat–1.at-0.55 V versus reversible hydrogen electrode. This catalyst also shows high long-term electrochemical stability and excellent selectivity for NH3 formation. Density functional theory calculations reveal that, by introducing oxygen vacancy on LaFeO3, the subsurface metallic ions are exposed with newly localized electronic states near the Fermi level, which facilitates the adsorption and activation of N2 molecules as well as the subsequent hydrogenation reactions.展开更多
The typical Haber technical process for industrial NH_(3)production involves plenty of energy-consumption and large quantities of greenhouse gas emission.In contrast,electrochemical N_(2)reduction proffers environment...The typical Haber technical process for industrial NH_(3)production involves plenty of energy-consumption and large quantities of greenhouse gas emission.In contrast,electrochemical N_(2)reduction proffers environment-friendly and energy-efficient avenues to synthesize NH_(3)at mild conditions but demands efficient electrocatalysts for the N_(2)reduction reaction(NRR).Herein we report for the first time that commercial indium-tin oxide glass(ITO/G)can be used as a catalyst electrode toward artificial N_(2)fixation,as it demonstrates excellent selectivity at mild conditions.Such ITO/G delivers excellent NRR performance with a NH_(3)yield of 1.06×10^(-10) mol s^(-1) cm^(-2) and a faradaic efficiency of 6.17%at-0.40 V versus the reversible hydrogen electrode(RHE)in 0.5 M LiClO4.Furthermore,the ITO/G also possesses good electrochemical stability and durability.Finally,the possible reaction mechanism for the NRR on the ITO catalysts was explored using first-principles calculations.展开更多
Infrared false target is an important mean to induce the infrared-guided weapons,and the key issue is how to keep the surface temperature of the infrared false target to be the same as that of the object to be protect...Infrared false target is an important mean to induce the infrared-guided weapons,and the key issue is how to keep the surface temperature of the infrared false target to be the same as that of the object to be protected.One-dimensional heat transfer models of a metal plate and imitative material were established to explore the influences of the thermophysical properties of imitative material on the surface temperature difference（STD） between the metal plate and imitative material which were subjected to periodical ambient conditions.It is elucidated that the STD is determined by the imitative material’s dimensionless thickness（dim*,） and the thermal inertia(Pim).When dim* is above 1.0,the STD is invariable as long as Pim is a constant.And if the dimensionless thickness of metal plate（d,m*） is also larger than 1.0,the STD approaches to zero as long as Pimis the same as the thermal inertia of metal plate（Pm）.When dim* is between 0.08 and 1,the STD varies irregularly with Pim and dim*.However,if dm* is also in the range of 0.08-1,the STD approaches to zero on condition that Pim=Pm and dim*= dm*.If dim*,is below 0.08,the STD is unchanged when Pimdim* is a constant.And if dm* is also less than 0.08,the STD approaches to zero as long as Pimdim* = Pmdm*.Furthermore,an applicationoriented discussion indicates that the imitative material can be both light and thin via the application of the phase change material with a preset STD because of its high specific heat capacity during the phase transition process.展开更多
Thermal catalytic degradation of organic pollutants conducted in the dark at room temperature under atmospheric pressure without the need of external chemicals and energy sources has attracted a lot of attention over ...Thermal catalytic degradation of organic pollutants conducted in the dark at room temperature under atmospheric pressure without the need of external chemicals and energy sources has attracted a lot of attention over the last two decades. It provides unparalleled advantages over other advanced oxidation processes (AOPs) in treating domestic and industrial contaminated wastewater from the viewpoint of energy/chemical conservation and ease of operation. Rich knowledge has been accumulated in terms of the synthesis and application of thermal catalysts though controversies remain regarding their underlying mechanisms. This review sheds light on the proposed thermo- catalysis mechanism for the first time and presents the development of thermal catalysts under dark ambient conditions with a focus on catalyst materials, catalytic activity, and mechanism. The present review aims to provide mechanistic insights into the rational design of novel and efficient catalysts, and their underlying mechanisms as well as the emerging challenges and perspectives in thermo-catalysis under dark ambient conditions used for the practical and efficient treatment of contaminated wastewater.展开更多
Two-dimensional(2D)oxides have been the focus of substantial research interest recently,owing to their fascinating physico-chemical properties.However,fabrication of large-area 2D oxide materials in a controlled manne...Two-dimensional(2D)oxides have been the focus of substantial research interest recently,owing to their fascinating physico-chemical properties.However,fabrication of large-area 2D oxide materials in a controlled manner under mild conditions still remains a formidable challenge.Herein,we develop a facile and universal strategy based on the sonochemistry approach for controllable and large-area growth of quasi-aligned single-crystalline ZnO nanosheets on a Zn substrate(Zn@SC-ZnO)under ambient conditions.The obtained ZnO nanosheets possess the desired exclusively exposed(001)facets,which have been confirmed to play a critical role in significantly reducing the activation energy and facilitating the stripping/plating processes of Zn.Accordingly,the constructed Zn@SC-ZnO||Zn@SC-ZnO symmetric cell has very low polarization overpotential down to~20 mV,with limited dendrite growth and side reactions for Zn anodes.The developed Zn@SC-ZnO//MnO_(2)aqueous Zn-ion batteries(ZIBs)show a voltage efficiency of 88.2%under 500 mA g^(-1)at the stage of 50%depth of discharge,which is state of the art for ZIBs reported to date.Furthermore,the as-assembled large-size cell(5 cm×5 cm)delivers an open circuit potential of 1.648 V,and can be robustly operated under a high current of 20 mA,showing excellent potential for future scalable applications.展开更多
To date,the synthesis of crystalline ZnO nanostructures was often performed under high temperatures and/or high pressures with tiny output,which limits their commercial applications.Herein,we report the progress on sy...To date,the synthesis of crystalline ZnO nanostructures was often performed under high temperatures and/or high pressures with tiny output,which limits their commercial applications.Herein,we report the progress on synthesizing single-crystalline ZnO nanosheets under ambient conditions(i.e.,room temperature(RT)and atmospheric pressure)based on a sonochemistry strategy.Furthermore,their controllable growth is accomplished by adjusting the pH values of solutions,enabling the tailored crystal growth habits on the polar-charged faces of ZnO along c-axis.As a proof of concept for their potential applications,the ZnO nanosheets exhibit highly efficient performance for sensing ammonia at RT,with ultrahigh sensitivity(S=610 at 100 ppm),excellent selectivity,rapid detection(response time/recover time=70 s/4 s),and outstanding detection limit down to 0.5 ppm,superior to those of all pure ZnO nanostructures and most ZnO-based composite counterparts ever reported.The present work might open a door for controllable production of ZnO nanostructures under mild conditions,and facilitate the exploration of modern gas sensors for detecting gaseous molecules at RT,which underscores their potential toward practical applications in opto-electronic nanodevices.展开更多
Crystallineγ-Ga_(2)O_(3)@rGO core-shell nanostructures are synthesized in gram scale,which are accomplished by a facile sonochemical strategy under ambient condition.They are composed of uniformγ-Ga_(2)O_(3)nanosphe...Crystallineγ-Ga_(2)O_(3)@rGO core-shell nanostructures are synthesized in gram scale,which are accomplished by a facile sonochemical strategy under ambient condition.They are composed of uniformγ-Ga_(2)O_(3)nanospheres encapsulated by reduced graphene oxide(rGO)nanolayers,and their formation is mainly attributed to the existed opposite zeta potential between the Ga_(2)O_(3)and rGO.The as-constructed lithium-ion batteries(LIBs)based on as-fabricatedγ-Ga_(2)O_(3)@rGO nanostructures deliver an initial discharge capacity of 1000 mAh g^(-1)at 100 mA g^(-1)and reversible capacity of 600 mAh g^(-1)under 500 mA g^(-1)after 1000 cycles,respectively,which are remarkably higher than those of pristineγ-Ga_(2)O_(3)with a much reduced lifetime of 100 cycles and much lower capacity.Ex situ XRD and XPS analyses demonstrate that the reversible LIBs storage is dominant by a conversion reaction and alloying mechanism,where the discharged product of liquid metal Ga exhibits self-healing ability,thus preventing the destroy of electrodes.Additionally,the rGO shell could act robustly as conductive network of the electrode for significantly improved conductivity,endowing the efficient Li storage behaviors.This work might provide some insight on mass production of advanced electrode materials under mild condition for energy storage and conversion applications.展开更多
Currently,the synthesis of nanostructures still encounters two grand challenges:one is the often-required high temperatures and/or high pressures,and the other is the scalable fabrication.Here,to break through such bo...Currently,the synthesis of nanostructures still encounters two grand challenges:one is the often-required high temperatures and/or high pressures,and the other is the scalable fabrication.Here,to break through such bottlenecks,we demonstrate an ambient-condition strategy for rapid mass production of fourthgeneration semiconductor Ga_(2)O_(3)nanoarchitectures assembled by single-crystalline nanosheets in a controlled manner based on sonochemistry.Their growth is fundamentally determined by the introduced ethanediamine in rationally designed source materials,which could not only protect the metal Ga against reacting with H_(2)O into GaOOH,but facilitate the reaction of Ga with OH·radicals for target crystalline Ga_(2)O_(3)nanostructures.As a proof of concept for applications,the as-fabricated Ga_(2)O_(3)nanoarchitectures exhibit superb performances for electromagnetic wave absorption with a reflection loss value of 52.2 dB at 8.1 GHz,and ammonia sensing with high sensitivity and selectivity at room temperature,representing their bright future to be commercially applied in modern devices.展开更多
Keggin-type molybdovanadophosphoric acids （HPA）, H4PMo11VO40 （1）, H5PMo10V2O40 （2） and H6PMo9V3O40 （3） were anchored onto γ-aminopropyltriethoxysilane （APTS） aminosilylated silica mesoporous SBA-15 through ...Keggin-type molybdovanadophosphoric acids （HPA）, H4PMo11VO40 （1）, H5PMo10V2O40 （2） and H6PMo9V3O40 （3） were anchored onto γ-aminopropyltriethoxysilane （APTS） aminosilylated silica mesoporous SBA-15 through acid-base neutralization and the resulting HPA/APTS/SBA-15 were characterized by BET, TEM, XRD, ICP, FFIR and ^31p MAS NMR. The characterization results indicate that the Keggin-structure of these HPAs is preserved within the mesoporous silica host. The samples were tested for catalytic aerobic oxidation of acetaldehyde heterogeneously in liquid phase under ambient condition. The electrostatic force between heteropoly acid and amino groups grafted on the silica channel surface leads to strong immobilization of HPA inside SBA-15 which is against the leaching during the reaction. The good catalytic performance and easy recycle of these catalysts make them as potential environmental friendly catalysts for elimination of indoor air pollutants.展开更多
Here,we report a Pd/PdO_(x) sensing material that achieves 1-s detection of 4% H_(2) gas(i.e.,the lower explosive limit concentration for H_(2))at room temperature in air.The Pd/PdO_(x) material is a network of interc...Here,we report a Pd/PdO_(x) sensing material that achieves 1-s detection of 4% H_(2) gas(i.e.,the lower explosive limit concentration for H_(2))at room temperature in air.The Pd/PdO_(x) material is a network of interconnected nanoscopic domains of Pd,PdO,and PdO_(2).Upon exposure to 4% H_(2),PdO and PdO_(2) in the Pd/PdO_(x) are immediately reduced to metallic Pd,generating over a>90% drop in electrical resistance.The mechanistic study reveals that the Pd/PdO_(2) interface in Pd/PdOx is responsible for the ultrafast PdO_(x) reduction.Metallic Pd at the Pd/PdO_(2) interface enables fast H_(2) dissociation to adsorbed H atoms,significantly lowering the PdO2 reduction barrier.In addition,control experiments suggest that the interconnectivity of Pd,PdO,and PdO2 in our Pd/PdO_(x) sensing material further facilitates the reduction of PdO,which would otherwise not occur.The 1-s response time of Pd/PdO_(x) under ambient conditions makes it an excellent alarm for the timely detection of hydrogen gas leaks.展开更多
Subject Code:H07 With the support from the National Natural Science Foundation of China and HGZ-CAS,a collaborative study by the research groups led by Prof.Chen Ping(陈萍)from Dalian Institute of Chemical Physics,Chi...Subject Code:H07 With the support from the National Natural Science Foundation of China and HGZ-CAS,a collaborative study by the research groups led by Prof.Chen Ping(陈萍)from Dalian Institute of Chemical Physics,Chinese Academy of Sciences and Prof.M.Dornheim,Helmholtz-Zentrum Geesthacht,Germany展开更多
Manipulating unintentional doping in graphene layers, which is influenced by environmental factors and supporting substrates, is of significant concern for the performance and advancement of graphene-based devices. In...Manipulating unintentional doping in graphene layers, which is influenced by environmental factors and supporting substrates, is of significant concern for the performance and advancement of graphene-based devices. In this context,laser-induced tuning of charge carriers in graphene facilitates the exploration of graphene's properties in relation to its surroundings and enables laser-assisted functionalization. This has the potential to advance optoelectronic devices that utilize graphene on transparent dielectric substrates, such as Al_(2)O_(3). In this work, laser power(PL) in Raman spectroscopy is used as a convenient contactless tool to manipulate and control unintentional carrier concentration and Fermi level position(EF) in graphene/α-Al_(2)O_(3)(G/Al_(2)O_(3)) under ambient conditions. Samples are annealed at 400℃ for two hours in an(Ar + H_(2)) atmosphere to remove any chemical residues. Analysis of the peak frequency(ω) and full width at half maximum(Γ) of the G and 2D bands show that G/Al_(2)O_(3) layers initially exhibit p-type doping, with EF located at ~100 me V below its Dirac charge-neutral point(DCNP). Increasing P_(L) results in effective carrier manipulation and raises E_F above DCNP. No significant internal stress is produced due to P_(L), as inferred from the strain-sensitive G^(*) band of graphene. Raman analysis of three successive cycles reveals hysteretic behavior from cycle to cycle, which is commonly reported to be limited by the type and density of the existing unintentional doping. Because of the ubiquitous nature of unintentional doping in graphene,manipulating it using contactless laser power to realize the desired graphene properties would be one of the best available practical approaches.展开更多
The efficient and stable abatement of CO pollutant under ambient conditions is of great significance;however,it remains a formidable challenge.Herein,we report the versatile application of wet oxidation over Fe(OH)x s...The efficient and stable abatement of CO pollutant under ambient conditions is of great significance;however,it remains a formidable challenge.Herein,we report the versatile application of wet oxidation over Fe(OH)x supported subnanometer Pt group metal(PGM)catalysts for the complete removal of CO under ambient temperature and humidity conditions.Typically,the 1.8 wt%Rh/Fe(OH)x catalyst exhibited better durability during a^1400 min run for wet oxidation than for dry CO oxidation.Multiple characterization results including HR-TEM,H2-TPR,and in-situ DRIFTS suggested that Fe(OH)x,with good reducibility,promoted by the subnanometer Rh clusters,provided sites for the adsorption and reaction of O2 and H2 O to form OH species.Subsequently,these OH species reacted with the adsorbed CO on Rh sites with a considerably lower activation energy(9 kJ mol^-1)than that of dissociated 0 species(22 kJ mol^-1),thus rationalizing the outstanding performance of Rh/Fe(OH)x for wet oxidation.Extended experiments with other PGMs revealed a good generality for the application of wet oxidation in the efficient abatement of CO under humid conditions with Fe(OH)x as the support.展开更多
Currently,the energy and capital intensive Haber–Bosch process still dominates NH_(3)synthesis which operates at high temperatures and pressures releasing inevitably large amounts of CO_(2).The electrocatalytic N_(2)...Currently,the energy and capital intensive Haber–Bosch process still dominates NH_(3)synthesis which operates at high temperatures and pressures releasing inevitably large amounts of CO_(2).The electrocatalytic N_(2)reduction reaction(NRR)offers us an environmentally-friendly and sustainable route for NH_(3)synthesis under ambient conditions.展开更多
The conventional Haber–Bosch process dominates the production of industrial NH_(3),and unfortunately leads to a large amount of energy consumption and carbon dioxide emissions.Meanwhile,from the environmentally frien...The conventional Haber–Bosch process dominates the production of industrial NH_(3),and unfortunately leads to a large amount of energy consumption and carbon dioxide emissions.Meanwhile,from the environmentally friendly and energy-saving point of view,electrocatalytic N_(2)fixation is gradually becoming a more promising and desirable alternative technique.Herein,multi-yolk–shell bismuth@porous carbon(MB@PC)composites were successfully synthesized via a facile simple hydrothermal reaction followed by a subsequent pyrolyzation.The as-prepared MB@PC composite can act as an efficient N_(2)reduction reaction(NRR)electrocatalyst under ambient conditions.Test results demonstrated that the MB@PC composite catalysts can deliver a high NH_(3)yield of 28.63μg h^(−1)mg^(−1)cat.,a Faraday efficiency of 10.58%at−0.5 V versus a reversible hydrogen electrode,long-term electrochemical durability in N_(2)-saturated 0.1 M HCl solution,and an excellent selectivity for NH_(3)formation,and are better than most reported bismuth-based electrocatalysts.The excellent NRR performance is mainly ascribed to the synergetic effect of good conductivity,the highly porous feature derived from the carbon framework and intrinsic electrocatalytic NRR activity of bismuth nanoparticles.Generally,the present research findings would provide an alternative avenue to produce other efficient non-precious metal electrocatalysts for clean energy applications.展开更多
The Haber Bosch industrial NH_(3) production process has high energy consumption and severe CO_(2) emission.Electrochemical N_(2) reduction is an attractive method for the synthesis of carbon-neutral NH_(3).However,si...The Haber Bosch industrial NH_(3) production process has high energy consumption and severe CO_(2) emission.Electrochemical N_(2) reduction is an attractive method for the synthesis of carbon-neutral NH_(3).However,since an efficient electrocatalyst is required to perform the N_(2) reduction reaction (NRR) at room temperature,N_(2) activation is a severe challenge.Herein,we report a CeP nanoparticle–reduced graphene oxide (CeP–rGO) hybrid as an effective electrocatalyst for NH_(3) synthesis.In 0.1 M HCl,CeP–rGO achieves a large NH_(3) yield of 28.69 μg h^(−1) mg_(cat.)^(−1) and a high faradaic efficiency of 9.6% at −0.40 V,and it also shows high electrochemical and structural stability.Density functional theory (DFT) calculations show that CeP can efficiently catalyze the synthesis of NH_(3).展开更多
Ambient ammonia synthesis via the electrochemical reduction of nitrate (NO_(3)^(-)) offers us a sustainable alternative to the industrial energy-intensive Haber–Bosch process. Here,we report on the development of NiF...Ambient ammonia synthesis via the electrochemical reduction of nitrate (NO_(3)^(-)) offers us a sustainable alternative to the industrial energy-intensive Haber–Bosch process. Here,we report on the development of NiFe_(2)O_(4) nanosheet arrays on carbon cloth (NiFe_(2)O_(4)/CC) for high-efficiency NH_(3) electrosynthesis via the selective reduction of NO_(3)^(-) under ambient conditions. When operated in 0.1 M phosphate-buffered solution with additional 0.1 M NaNO_(3),such NiFe_(2)O_(4)/CC achieves a remarkable faradaic efficiency of 96.6% and a high NH_(3) yield of up to 10.3 mg h^(-1) cm^(-2). Furthermore,it possesses excellent electrochemical and structural stability. The theoretical calculations reveal that the metallic NiFe_(2)O_(4) surface has strong interactions with NO_(3)^(-) and can seriously inhibit the HER aiding in more efficient NO_(3)^(-) reduction to NH_(3).展开更多
Ammonia is a large-scale commodity chemical that is crucial for producing nitrogen-containing fertilizers.Recently,the electrocatalytic nitrogen reduction reaction(NRR)has attracted worldwide research attention as a p...Ammonia is a large-scale commodity chemical that is crucial for producing nitrogen-containing fertilizers.Recently,the electrocatalytic nitrogen reduction reaction(NRR)has attracted worldwide research attention as a promising route to achieve green and sustainable ammonia.Here,under ambient conditions,a facile strategy was developed for fabrication of a copper-based catalyst supported on sulfonate group functionalized activated carbon(Cu/AC-S),which shows superior NRR activity with a high NH_(3) yield rate of 9.7μg h^(-1) mg^(-1) and a faradaic efficiency of 15.9%at-0.3 V(vs.reversible hydrogen electrode,RHE),due to the suppression of the hydrogen evolution reaction(HER)caused by the sulfonate group.展开更多
基金The authors would like to make an appreciation to the National Natural Science Foundation of China(No.51874280)the Fundamental Research Funds of the Central Universities(No.2021ZDPY0211)for financial support.
文摘The environmental concerns resulting from coal-fired power generation that produces large amounts of CO_(2)and fly ash are of great interest.To mitigate,this study aims to develop a novel carbonated CO_(2)-fly ash-based backfill(CFBF)material under ambient conditions.The performance of CFBF was investigated for different fly ash-cement ratios and compared with non-CO_(2)reacted samples.The fresh CFBF slurry conformed to the Herschel-Bulkley model with shear thinning characteristics.After carbonation,the yield stress of the fresh slurry increased significantly by lowering fly ash ratio due to gel formation.The setting times were accelerated,resulting in approximately 40.6%of increased early strength.The final strength decreased when incorporating a lower fly ash ratio(50%and 60%),which was related to the existing heterogeneous pores caused by rapid fluid loss.The strength increased with fly ash content above 70%because additional C-S(A)-H and silica gels were characterized to precipitate on the grain surface,so the binding between particles increased.The C-S(A)-H gel was developed through the pozzolanic reaction,where CaCO_(3)was the prerequisite calcium source obtained in the CO_(2)-fly ash reaction.Furthermore,the maximum CO_(2)uptake efficiency was 1.39 mg-CO_(2)/g-CFBF.The CFBF material is feasible to co-dispose CO_(2)and fly ash in the mine goaf as negative carbon backfill materials,and simultaneously mitigates the strata movement and water lost in post-subsurface mining.
基金supported by the National Natural Science Foundation of China(grant no.21904071 and 22071115)。
文摘Electrochemical nitrogen reduction reaction(e-NRR)under ambient conditions is an emerging strategy to tackle the hydrogen-and energy-intensive operations for traditional Haber-Bosch process in industrial ammonia(NH_(3))synthesis.However,the e-NRR performance is currently impeded by the inherent inertness of N_(2) molecules,the extremely slow kinetics and the overwhelming competition from the hydrogen evolution reaction(HER),all of which cause unsatisfied yield and ammonia selectivity(Faradaic efficiency,FE).Defect and interface engineering are capable of achieving novel physical and chemical properties as well as superior synergistic effects for various electrocatalysts.In this review,we first provide a general introduction to the NRR mechanism.We then focus on the recent progress in defect and interface engineering and summarize how defect and interface can be rationally designed and functioned in NRR catalysts.Particularly,the origin of superior NRR catalytic activity by applying these approaches was discussed from both theoretical and experimental perspectives.Finally,the remaining challenges and future perspectives in this emerging area are highlighted.It is expected that this review will shed some light on designing NRR electrocatalysts with excellent activity,selectivity and stability.
基金the National Natural Science Foundation of China(Nos.21575137 and 11704005)。
文摘Electrocatalytic N2 reduction to NH3 under ambient conditions is an eco-friendly and sustainable alternative to the traditional Haber-Bosch process. However, inhibited by the high activation barrier of N2, this process needs efficient electrocatalysts to adsorb and activate the N2, enabling the N2 reduction reaction(NRR). Herein, we report that porous LaFeO3 nanofiber with oxygen vacancies acts as an efficient NRR electrocatalyst with abundant active sites to enhance the adsorption and activation of N2. When tested in 0.1 M HCl, such electrocatalyst achieves a high Faradaic efficiency of 8.77% and a large NH3 yield rate of 18.59 μg h–1 mgcat–1.at-0.55 V versus reversible hydrogen electrode. This catalyst also shows high long-term electrochemical stability and excellent selectivity for NH3 formation. Density functional theory calculations reveal that, by introducing oxygen vacancy on LaFeO3, the subsurface metallic ions are exposed with newly localized electronic states near the Fermi level, which facilitates the adsorption and activation of N2 molecules as well as the subsequent hydrogenation reactions.
文摘The typical Haber technical process for industrial NH_(3)production involves plenty of energy-consumption and large quantities of greenhouse gas emission.In contrast,electrochemical N_(2)reduction proffers environment-friendly and energy-efficient avenues to synthesize NH_(3)at mild conditions but demands efficient electrocatalysts for the N_(2)reduction reaction(NRR).Herein we report for the first time that commercial indium-tin oxide glass(ITO/G)can be used as a catalyst electrode toward artificial N_(2)fixation,as it demonstrates excellent selectivity at mild conditions.Such ITO/G delivers excellent NRR performance with a NH_(3)yield of 1.06×10^(-10) mol s^(-1) cm^(-2) and a faradaic efficiency of 6.17%at-0.40 V versus the reversible hydrogen electrode(RHE)in 0.5 M LiClO4.Furthermore,the ITO/G also possesses good electrochemical stability and durability.Finally,the possible reaction mechanism for the NRR on the ITO catalysts was explored using first-principles calculations.
基金funded by the National Natural Science Foundation of China (No. 51576188)
文摘Infrared false target is an important mean to induce the infrared-guided weapons,and the key issue is how to keep the surface temperature of the infrared false target to be the same as that of the object to be protected.One-dimensional heat transfer models of a metal plate and imitative material were established to explore the influences of the thermophysical properties of imitative material on the surface temperature difference（STD） between the metal plate and imitative material which were subjected to periodical ambient conditions.It is elucidated that the STD is determined by the imitative material’s dimensionless thickness（dim*,） and the thermal inertia(Pim).When dim* is above 1.0,the STD is invariable as long as Pim is a constant.And if the dimensionless thickness of metal plate（d,m*） is also larger than 1.0,the STD approaches to zero as long as Pimis the same as the thermal inertia of metal plate（Pm）.When dim* is between 0.08 and 1,the STD varies irregularly with Pim and dim*.However,if dm* is also in the range of 0.08-1,the STD approaches to zero on condition that Pim=Pm and dim*= dm*.If dim*,is below 0.08,the STD is unchanged when Pimdim* is a constant.And if dm* is also less than 0.08,the STD approaches to zero as long as Pimdim* = Pmdm*.Furthermore,an applicationoriented discussion indicates that the imitative material can be both light and thin via the application of the phase change material with a preset STD because of its high specific heat capacity during the phase transition process.
基金funding support by the National Natural Science Foundation of China (51674091, 51104048)~~
文摘Thermal catalytic degradation of organic pollutants conducted in the dark at room temperature under atmospheric pressure without the need of external chemicals and energy sources has attracted a lot of attention over the last two decades. It provides unparalleled advantages over other advanced oxidation processes (AOPs) in treating domestic and industrial contaminated wastewater from the viewpoint of energy/chemical conservation and ease of operation. Rich knowledge has been accumulated in terms of the synthesis and application of thermal catalysts though controversies remain regarding their underlying mechanisms. This review sheds light on the proposed thermo- catalysis mechanism for the first time and presents the development of thermal catalysts under dark ambient conditions with a focus on catalyst materials, catalytic activity, and mechanism. The present review aims to provide mechanistic insights into the rational design of novel and efficient catalysts, and their underlying mechanisms as well as the emerging challenges and perspectives in thermo-catalysis under dark ambient conditions used for the practical and efficient treatment of contaminated wastewater.
基金the National Natural Science Foundation of China(NSFC,Grant No.51972178)the Natural Science Foundation of Ningbo(2022J139)the Ningbo Yongjiang Talent Introduction Programme(2022A-227-G).
文摘Two-dimensional(2D)oxides have been the focus of substantial research interest recently,owing to their fascinating physico-chemical properties.However,fabrication of large-area 2D oxide materials in a controlled manner under mild conditions still remains a formidable challenge.Herein,we develop a facile and universal strategy based on the sonochemistry approach for controllable and large-area growth of quasi-aligned single-crystalline ZnO nanosheets on a Zn substrate(Zn@SC-ZnO)under ambient conditions.The obtained ZnO nanosheets possess the desired exclusively exposed(001)facets,which have been confirmed to play a critical role in significantly reducing the activation energy and facilitating the stripping/plating processes of Zn.Accordingly,the constructed Zn@SC-ZnO||Zn@SC-ZnO symmetric cell has very low polarization overpotential down to~20 mV,with limited dendrite growth and side reactions for Zn anodes.The developed Zn@SC-ZnO//MnO_(2)aqueous Zn-ion batteries(ZIBs)show a voltage efficiency of 88.2%under 500 mA g^(-1)at the stage of 50%depth of discharge,which is state of the art for ZIBs reported to date.Furthermore,the as-assembled large-size cell(5 cm×5 cm)delivers an open circuit potential of 1.648 V,and can be robustly operated under a high current of 20 mA,showing excellent potential for future scalable applications.
基金This work was supported by the National Natural Science Foundation of China(Grant No.51972178)Hunan Provincial Innovation Foundation for Postgraduate(Grant No.CX20200454).
文摘To date,the synthesis of crystalline ZnO nanostructures was often performed under high temperatures and/or high pressures with tiny output,which limits their commercial applications.Herein,we report the progress on synthesizing single-crystalline ZnO nanosheets under ambient conditions(i.e.,room temperature(RT)and atmospheric pressure)based on a sonochemistry strategy.Furthermore,their controllable growth is accomplished by adjusting the pH values of solutions,enabling the tailored crystal growth habits on the polar-charged faces of ZnO along c-axis.As a proof of concept for their potential applications,the ZnO nanosheets exhibit highly efficient performance for sensing ammonia at RT,with ultrahigh sensitivity(S=610 at 100 ppm),excellent selectivity,rapid detection(response time/recover time=70 s/4 s),and outstanding detection limit down to 0.5 ppm,superior to those of all pure ZnO nanostructures and most ZnO-based composite counterparts ever reported.The present work might open a door for controllable production of ZnO nanostructures under mild conditions,and facilitate the exploration of modern gas sensors for detecting gaseous molecules at RT,which underscores their potential toward practical applications in opto-electronic nanodevices.
基金supported by National Natural Science Foundation of China(NSFC,Grant No.51972178)Natural Science Foundation of Ningbo(2022J139)Ningbo Yongjiang Talent Introduction Programme(2022A-227-G)
文摘Crystallineγ-Ga_(2)O_(3)@rGO core-shell nanostructures are synthesized in gram scale,which are accomplished by a facile sonochemical strategy under ambient condition.They are composed of uniformγ-Ga_(2)O_(3)nanospheres encapsulated by reduced graphene oxide(rGO)nanolayers,and their formation is mainly attributed to the existed opposite zeta potential between the Ga_(2)O_(3)and rGO.The as-constructed lithium-ion batteries(LIBs)based on as-fabricatedγ-Ga_(2)O_(3)@rGO nanostructures deliver an initial discharge capacity of 1000 mAh g^(-1)at 100 mA g^(-1)and reversible capacity of 600 mAh g^(-1)under 500 mA g^(-1)after 1000 cycles,respectively,which are remarkably higher than those of pristineγ-Ga_(2)O_(3)with a much reduced lifetime of 100 cycles and much lower capacity.Ex situ XRD and XPS analyses demonstrate that the reversible LIBs storage is dominant by a conversion reaction and alloying mechanism,where the discharged product of liquid metal Ga exhibits self-healing ability,thus preventing the destroy of electrodes.Additionally,the rGO shell could act robustly as conductive network of the electrode for significantly improved conductivity,endowing the efficient Li storage behaviors.This work might provide some insight on mass production of advanced electrode materials under mild condition for energy storage and conversion applications.
基金Top Talent Project of Ningbo Municipal Government,National Natural Science Foundation of China(No.51972178)。
文摘Currently,the synthesis of nanostructures still encounters two grand challenges:one is the often-required high temperatures and/or high pressures,and the other is the scalable fabrication.Here,to break through such bottlenecks,we demonstrate an ambient-condition strategy for rapid mass production of fourthgeneration semiconductor Ga_(2)O_(3)nanoarchitectures assembled by single-crystalline nanosheets in a controlled manner based on sonochemistry.Their growth is fundamentally determined by the introduced ethanediamine in rationally designed source materials,which could not only protect the metal Ga against reacting with H_(2)O into GaOOH,but facilitate the reaction of Ga with OH·radicals for target crystalline Ga_(2)O_(3)nanostructures.As a proof of concept for applications,the as-fabricated Ga_(2)O_(3)nanoarchitectures exhibit superb performances for electromagnetic wave absorption with a reflection loss value of 52.2 dB at 8.1 GHz,and ammonia sensing with high sensitivity and selectivity at room temperature,representing their bright future to be commercially applied in modern devices.
基金Project supported by the National Natural Science Foundation Committee of China （Nos. 20371013, 20273017, 20421303） and the Major State Basic Research Development Program of China （No. 2003CB615807）.
文摘Keggin-type molybdovanadophosphoric acids （HPA）, H4PMo11VO40 （1）, H5PMo10V2O40 （2） and H6PMo9V3O40 （3） were anchored onto γ-aminopropyltriethoxysilane （APTS） aminosilylated silica mesoporous SBA-15 through acid-base neutralization and the resulting HPA/APTS/SBA-15 were characterized by BET, TEM, XRD, ICP, FFIR and ^31p MAS NMR. The characterization results indicate that the Keggin-structure of these HPAs is preserved within the mesoporous silica host. The samples were tested for catalytic aerobic oxidation of acetaldehyde heterogeneously in liquid phase under ambient condition. The electrostatic force between heteropoly acid and amino groups grafted on the silica channel surface leads to strong immobilization of HPA inside SBA-15 which is against the leaching during the reaction. The good catalytic performance and easy recycle of these catalysts make them as potential environmental friendly catalysts for elimination of indoor air pollutants.
基金The work at Wayne State University and the Pacific Northwest National Laboratory was supported by the U.S.Department of Energy(DOE),Office of Science,Office of Basic Energy Sciences,through Award#78705In addition,L.L.and X.G.acknowledge support from National Science Foundation under award CHE-1943737.L.Z.and S.W.L.acknowledge support from the National Natural Science Foundation of China(No.22103047)Hefei National Laboratory for Physical Sciences at the Microscale(No.KF2020107).
文摘Here,we report a Pd/PdO_(x) sensing material that achieves 1-s detection of 4% H_(2) gas(i.e.,the lower explosive limit concentration for H_(2))at room temperature in air.The Pd/PdO_(x) material is a network of interconnected nanoscopic domains of Pd,PdO,and PdO_(2).Upon exposure to 4% H_(2),PdO and PdO_(2) in the Pd/PdO_(x) are immediately reduced to metallic Pd,generating over a>90% drop in electrical resistance.The mechanistic study reveals that the Pd/PdO_(2) interface in Pd/PdOx is responsible for the ultrafast PdO_(x) reduction.Metallic Pd at the Pd/PdO_(2) interface enables fast H_(2) dissociation to adsorbed H atoms,significantly lowering the PdO2 reduction barrier.In addition,control experiments suggest that the interconnectivity of Pd,PdO,and PdO2 in our Pd/PdO_(x) sensing material further facilitates the reduction of PdO,which would otherwise not occur.The 1-s response time of Pd/PdO_(x) under ambient conditions makes it an excellent alarm for the timely detection of hydrogen gas leaks.
文摘Subject Code:H07 With the support from the National Natural Science Foundation of China and HGZ-CAS,a collaborative study by the research groups led by Prof.Chen Ping(陈萍)from Dalian Institute of Chemical Physics,Chinese Academy of Sciences and Prof.M.Dornheim,Helmholtz-Zentrum Geesthacht,Germany
基金the Deputyship for Research & Innovation, Ministry of Education in Saudi Arabia for funding this research work through the project number 445-9-687。
文摘Manipulating unintentional doping in graphene layers, which is influenced by environmental factors and supporting substrates, is of significant concern for the performance and advancement of graphene-based devices. In this context,laser-induced tuning of charge carriers in graphene facilitates the exploration of graphene's properties in relation to its surroundings and enables laser-assisted functionalization. This has the potential to advance optoelectronic devices that utilize graphene on transparent dielectric substrates, such as Al_(2)O_(3). In this work, laser power(PL) in Raman spectroscopy is used as a convenient contactless tool to manipulate and control unintentional carrier concentration and Fermi level position(EF) in graphene/α-Al_(2)O_(3)(G/Al_(2)O_(3)) under ambient conditions. Samples are annealed at 400℃ for two hours in an(Ar + H_(2)) atmosphere to remove any chemical residues. Analysis of the peak frequency(ω) and full width at half maximum(Γ) of the G and 2D bands show that G/Al_(2)O_(3) layers initially exhibit p-type doping, with EF located at ~100 me V below its Dirac charge-neutral point(DCNP). Increasing P_(L) results in effective carrier manipulation and raises E_F above DCNP. No significant internal stress is produced due to P_(L), as inferred from the strain-sensitive G^(*) band of graphene. Raman analysis of three successive cycles reveals hysteretic behavior from cycle to cycle, which is commonly reported to be limited by the type and density of the existing unintentional doping. Because of the ubiquitous nature of unintentional doping in graphene,manipulating it using contactless laser power to realize the desired graphene properties would be one of the best available practical approaches.
基金supported by the National Natural Science Foundation of China(21576251,21676269,21808212,21878283)the Youth Innovation Promotion Association CAS(2017223)+5 种基金the “Strategic Priority Research Program” of the Chinese Academy of Sciences(XDB17020100)National Key Projects for Fundamental Research and Development of China(2016YFA0202801)China Postdoctoral Science Foundation(2019M652578)the Postdoctoral Sponsorship in Henan Province(1902015)Science and Technology Program of Henan Province(192102210034)Zhongyuan Postdoctoral Program for Innovation Talents~~
文摘The efficient and stable abatement of CO pollutant under ambient conditions is of great significance;however,it remains a formidable challenge.Herein,we report the versatile application of wet oxidation over Fe(OH)x supported subnanometer Pt group metal(PGM)catalysts for the complete removal of CO under ambient temperature and humidity conditions.Typically,the 1.8 wt%Rh/Fe(OH)x catalyst exhibited better durability during a^1400 min run for wet oxidation than for dry CO oxidation.Multiple characterization results including HR-TEM,H2-TPR,and in-situ DRIFTS suggested that Fe(OH)x,with good reducibility,promoted by the subnanometer Rh clusters,provided sites for the adsorption and reaction of O2 and H2 O to form OH species.Subsequently,these OH species reacted with the adsorbed CO on Rh sites with a considerably lower activation energy(9 kJ mol^-1)than that of dissociated 0 species(22 kJ mol^-1),thus rationalizing the outstanding performance of Rh/Fe(OH)x for wet oxidation.Extended experiments with other PGMs revealed a good generality for the application of wet oxidation in the efficient abatement of CO under humid conditions with Fe(OH)x as the support.
基金the National Key Research and Development Program of China(No.2017YFB0307504)the National Natural Science Foundation of China(No.21506133)the Youth Foundation of Sichuan University(No.2017SCU04a08)for their support in this research.
文摘Currently,the energy and capital intensive Haber–Bosch process still dominates NH_(3)synthesis which operates at high temperatures and pressures releasing inevitably large amounts of CO_(2).The electrocatalytic N_(2)reduction reaction(NRR)offers us an environmentally-friendly and sustainable route for NH_(3)synthesis under ambient conditions.
基金funding support from the Science and Technology Committee of Shaanxi Province(No.2011KGXX47)the fund of the State Key Laboratory of Solidification Processing in NWPU(No.SKLSP201845)+2 种基金the National Key Research and Development Program(Grants No.2018YFA0208600)the Fundamental Research Funds for the Central UniversitiesThe calculations were performed on the supercomputing system in USTC-SCC and Guangzhou-SCC.
文摘The conventional Haber–Bosch process dominates the production of industrial NH_(3),and unfortunately leads to a large amount of energy consumption and carbon dioxide emissions.Meanwhile,from the environmentally friendly and energy-saving point of view,electrocatalytic N_(2)fixation is gradually becoming a more promising and desirable alternative technique.Herein,multi-yolk–shell bismuth@porous carbon(MB@PC)composites were successfully synthesized via a facile simple hydrothermal reaction followed by a subsequent pyrolyzation.The as-prepared MB@PC composite can act as an efficient N_(2)reduction reaction(NRR)electrocatalyst under ambient conditions.Test results demonstrated that the MB@PC composite catalysts can deliver a high NH_(3)yield of 28.63μg h^(−1)mg^(−1)cat.,a Faraday efficiency of 10.58%at−0.5 V versus a reversible hydrogen electrode,long-term electrochemical durability in N_(2)-saturated 0.1 M HCl solution,and an excellent selectivity for NH_(3)formation,and are better than most reported bismuth-based electrocatalysts.The excellent NRR performance is mainly ascribed to the synergetic effect of good conductivity,the highly porous feature derived from the carbon framework and intrinsic electrocatalytic NRR activity of bismuth nanoparticles.Generally,the present research findings would provide an alternative avenue to produce other efficient non-precious metal electrocatalysts for clean energy applications.
基金supported by the National Natural Science Foundation of China(No.21575137).
文摘The Haber Bosch industrial NH_(3) production process has high energy consumption and severe CO_(2) emission.Electrochemical N_(2) reduction is an attractive method for the synthesis of carbon-neutral NH_(3).However,since an efficient electrocatalyst is required to perform the N_(2) reduction reaction (NRR) at room temperature,N_(2) activation is a severe challenge.Herein,we report a CeP nanoparticle–reduced graphene oxide (CeP–rGO) hybrid as an effective electrocatalyst for NH_(3) synthesis.In 0.1 M HCl,CeP–rGO achieves a large NH_(3) yield of 28.69 μg h^(−1) mg_(cat.)^(−1) and a high faradaic efficiency of 9.6% at −0.40 V,and it also shows high electrochemical and structural stability.Density functional theory (DFT) calculations show that CeP can efficiently catalyze the synthesis of NH_(3).
基金supported by the National Natural Science Foundation of China(No.22072015)。
文摘Ambient ammonia synthesis via the electrochemical reduction of nitrate (NO_(3)^(-)) offers us a sustainable alternative to the industrial energy-intensive Haber–Bosch process. Here,we report on the development of NiFe_(2)O_(4) nanosheet arrays on carbon cloth (NiFe_(2)O_(4)/CC) for high-efficiency NH_(3) electrosynthesis via the selective reduction of NO_(3)^(-) under ambient conditions. When operated in 0.1 M phosphate-buffered solution with additional 0.1 M NaNO_(3),such NiFe_(2)O_(4)/CC achieves a remarkable faradaic efficiency of 96.6% and a high NH_(3) yield of up to 10.3 mg h^(-1) cm^(-2). Furthermore,it possesses excellent electrochemical and structural stability. The theoretical calculations reveal that the metallic NiFe_(2)O_(4) surface has strong interactions with NO_(3)^(-) and can seriously inhibit the HER aiding in more efficient NO_(3)^(-) reduction to NH_(3).
基金supported by the Natural Science Foundation of China(Grant No.51672277 and 61804154)the CAS/SAFEA International Partnership Program for Creative Research Teams of Chinese Academy of Sciences,China。
文摘Ammonia is a large-scale commodity chemical that is crucial for producing nitrogen-containing fertilizers.Recently,the electrocatalytic nitrogen reduction reaction(NRR)has attracted worldwide research attention as a promising route to achieve green and sustainable ammonia.Here,under ambient conditions,a facile strategy was developed for fabrication of a copper-based catalyst supported on sulfonate group functionalized activated carbon(Cu/AC-S),which shows superior NRR activity with a high NH_(3) yield rate of 9.7μg h^(-1) mg^(-1) and a faradaic efficiency of 15.9%at-0.3 V(vs.reversible hydrogen electrode,RHE),due to the suppression of the hydrogen evolution reaction(HER)caused by the sulfonate group.
