Research on two-dimensional(2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since ...Research on two-dimensional(2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since the mechanical exfoliation of graphene in 2004. Starting from graphene, 2D materials now have become a big family with numerous members and diverse categories. The unique structural features and physicochemical properties of 2D materials make them one class of the most appealing candidates for a wide range of potential applications. In particular, we have seen some major breakthroughs made in the field of 2D materials in last five years not only in developing novel synthetic methods and exploring new structures/properties but also in identifying innovative applications and pushing forward commercialisation. In this review, we provide a critical summary on the recent progress made in the field of 2D materials with a particular focus on last five years. After a brief backgroundintroduction, we first discuss the major synthetic methods for 2D materials, including the mechanical exfoliation, liquid exfoliation, vapor phase deposition, and wet-chemical synthesis as well as phase engineering of 2D materials belonging to the field of phase engineering of nanomaterials(PEN). We then introduce the superconducting/optical/magnetic properties and chirality of 2D materials along with newly emerging magic angle 2D superlattices. Following that, the promising applications of 2D materials in electronics, optoelectronics, catalysis, energy storage, solar cells, biomedicine, sensors, environments, etc. are described sequentially. Thereafter, we present the theoretic calculations and simulations of 2D materials. Finally, after concluding the current progress, we provide some personal discussions on the existing challenges and future outlooks in this rapidly developing field.展开更多
AIM： To use the tyrosinase minigene as a visual marker to perform microinjection training and improve the techniques related with transgene to greatly elevate the effidency of gene transfer. METHODS： A mouse tyrosin...AIM： To use the tyrosinase minigene as a visual marker to perform microinjection training and improve the techniques related with transgene to greatly elevate the effidency of gene transfer. METHODS： A mouse tyrosinase minigene, i.e., TyBS, in which the 2.25-kb authentic genomic 5＇ non-coding flanking sequence of mouse tyrosinase was fused to a mouse tyrosinase cDNA, was introduced into the fertilized eggs of outbred Kunming albino mice. RESULTS： Of the 11 animals that developed from the injected eggs, two mice （P1 and #8） exhibited pigmented hair （P1） and eyes （P1 and #8）, as confirmed by PCR analysis for the tyrosinase minigene integrated into the genome. When founder P1 was bred to Kunming male mouse, six progeny out of 11 offspring inherited the transgene and the pigmented-eye phenotype. CONCLUSION： Taken together, these results suggest that this minigene encodes the active tyrosinase protein and that its 5＇ flanking region contains the sequences regulating the expression of mouse tyrosinase gene as expected. We have rescued the albino phenotype by introduction and expression of a functional tyrosinase minigene in the Kunming albino mouse and the transgene can be passed to subsequent generation. These findings also indicate that TyBS can be a useful visual marker gene in the co-transgenic experiments.展开更多
IrRu bimetallic oxides are recognized as the promising acidic oxygen evolution reaction(OER)catalysts,but breaking the trade-off between their activity and stability is an unresolved question.Meanwhile,addressing the ...IrRu bimetallic oxides are recognized as the promising acidic oxygen evolution reaction(OER)catalysts,but breaking the trade-off between their activity and stability is an unresolved question.Meanwhile,addressing the issues of mass transport obstruction of IrRu bimetallic oxides under high current remains a challenge for the development of proton exchange membrane water electrolysis(PEM-WE).Herein,we prepared an IrRuO_(x)nanomeshes(IrRuO_(x)NMs)with high coordination number(CN)of Ir-O-Ru bonds in a mixed molten salt with high solubility of the Ir/Ru precursor.X-ray absorption spectroscopy analysis revealed that the IrRuO_(x)NMs possess high coordination number of Ir-O-Ru bonds(CNIr-O-Ru=5.6)with a distance of 3.18Å.Moreover,the nanomesh structures of IrRuO_(x)NMs provided hierarchical channels to accelerate the transport of oxygen and water,thus further improving the electrochemical activity.Consequently,the IrRuO_(x)NMs as OER catalysts can simultaneously achieve high activity and stability with low overpotential of 196 mV to reach 10 mA·cm^(−2)and slightly increase by 70 mV over 650 h test.Differential electrochemical mass spectrometry tests suggest that the preferred OER mechanism for IrRuO_(x)NMs is the adsorbent evolution mechanism,which is beneficial for the robust structural stability.展开更多
The electrochemical CO_(2) reduction reaction(CO_(2)RR)holds significant promise in advancing carbon neutrality.Developing catalysts for the electrochemical CO_(2)RR to multi-carbon(C_(2+))products(e.g.,C_(2)H_(4))und...The electrochemical CO_(2) reduction reaction(CO_(2)RR)holds significant promise in advancing carbon neutrality.Developing catalysts for the electrochemical CO_(2)RR to multi-carbon(C_(2+))products(e.g.,C_(2)H_(4))under industrial-level current density is urgently needed and pivotal.Herein,we report the Cu_(2)O nanoparticles doped with interstitial carbon atoms(denoted as C-Cu_(2)O NPs)for the conversion of CO_(2) to C_(2+)products.The interstitial carbon promotes the C-Cu_(2)O NPs to possess abundant unsaturated Cu–O bonds,leading to a high-density Cu^(δ+)(0<δ<1)species.The obtained C-Cu_(2)O NPs exhibited significant Faradic efficiency(FE)of C_(2+) products approaching 76.9%and a partial current density reaching 615.2 mA·cm^(–2)under an industrial-level current density of 800 mA·cm^(–2).Furthermore,the efficient electrosynthesis of C_(2)H_(4) achieved an FE of 57.4%with a partial current density of 459.2 mA·cm^(–2).In situ electrochemical attenuated total reflection Fourier transform infrared spectroscopy and in situ Raman spectroscopy analyses revealed that C-Cu_(2)O NPs stabilized the intermediate*CO and facilitated C–C coupling,leading to increased selectivity towards C_(2+) products.展开更多
The efficiency of proton exchange membrane water electrolysis(PEM-WE)for hydrogen production is heavily dependent on the noble metal iridium-based catalysts.However,the scarcity of iridium limits the large-scale appli...The efficiency of proton exchange membrane water electrolysis(PEM-WE)for hydrogen production is heavily dependent on the noble metal iridium-based catalysts.However,the scarcity of iridium limits the large-scale application of PEM-WE.To address this issue,it is promising to select an appropriate support because it not only enhances the utilization efficiency of noble metals but also improves mass transport under high current.Herein,we supported amorphous IrO_(x) nanosheets onto the hollow TiO_(2) sphere(denoted as IrO_(x)),which demonstrated excellent performance in acidic electrolytic water splitting.Specifically,the annealed IrO_(x)catalyst at 150℃in air exhibited a mass activity of 1347.5 A·gIr^(−1),which is much higher than that of commercial IrO_(2) of 12.33 A·gIr^(−1) at the overpotential of 300 mV for oxygen evolution reaction(OER).Meanwhile,the annealed IrO_(x) exhibited good stability for 600 h operating at 10 mA·cm^(−2).Moreover,when using IrO_(x) and annealed IrO_(x) catalysts for water splitting,a cell voltage as low as 1.485 V can be achieved at 10 mA·cm^(−2).The cell can continuously operate for 200 h with negligible degradation of performance.展开更多
To unveil the nature of amorphous states,single-element amorphous metals have been the perfect research subject due to the simplest composition.However,the extreme crystal nucleation and growth rate in single-element ...To unveil the nature of amorphous states,single-element amorphous metals have been the perfect research subject due to the simplest composition.However,the extreme crystal nucleation and growth rate in single-element metal make the synthesis of single-element amorphous metals seemingly impossible in the past.Fortunately,benefited by several delicate synthetic strategies developed recently,the single-element amorphous metals have been successfully demonstrated.This review aims to provide a systematic overview of the synthesis of single-element amorphous metals covering the challenges in physics and recent achieve-ments.In addition,current understanding of the atomic and electronic structures of single-element amorphous metal has also been included.Finally,the challenges that worth further investigation are discussed.By identifying the potential avenues for further exploration,this review aims to contribute valuable insights that will propel the cognition of single-element amorphous metals.展开更多
Manipulating the oxidation state of Cu catalysts can significantly affect the selectivity and activity of electrocatalytic carbon dioxide reduction(CO_(2)RR).However,the thermodynamically favorable cathodic reduction ...Manipulating the oxidation state of Cu catalysts can significantly affect the selectivity and activity of electrocatalytic carbon dioxide reduction(CO_(2)RR).However,the thermodynamically favorable cathodic reduction to metallic states typically leads to catalytic deactivation.Herein,a defect construction strategy is employed to prepare crystalline/amorphous Cu_(2+1)O/CuO_(x)heterostructures(c/a-CuO_(x))with abundant Cu0 and Cuδ+(0<δ<1)sites for CO_(2)RR.The C^(2+)Faradaic efficiency of the heterostructured Cu catalyst is up to 81.3%,with partial current densities of 406.7 mA·cm−2.Significantly,real-time monitoring of the Cu oxidation state evolution by in-situ Raman spectroscopy confirms the stability of Cuδ+species under long-term high current density operation.Density functional theory(DFT)calculations further reveal that the adjacent Cu0 and Cuδ+sites in heterostructured c/a-CuO_(x)can efficiently reduce the energy barrier of CO coupling for C^(2+)products.展开更多
Highly efficient and stable oxygen reduction reaction(ORR)electrocatalysts are remarkably important but challenging for advancing the large-scale commercialization of practical proton exchange membrane fuel cells(PEMF...Highly efficient and stable oxygen reduction reaction(ORR)electrocatalysts are remarkably important but challenging for advancing the large-scale commercialization of practical proton exchange membrane fuel cells(PEMFCs).In this work,we report that the introduction of interstitial hydrogen atoms into PtPd nanotubes can significantly promote ORR performance without scarifying the durability.The enhanced mass activity was 8.8 times higher than that of commercial Pt/C.The accelerated durability test showed negligible activity attenuation after 30,000 cycles.Additionally,H2/O2 fuel cell tests further verified the excellent activity of PtPd-H nanotubes with a maximum power density of 1.32 W·cm^(−2),superior to that of commercial Pt/C(1.16 W·cm^(−2)).Density functional theory calculations demonstrated the incorporation of hydrogen atoms gives rise to the broadening of Pt d-band and the downshift of d-band center,which consequently leads to the weaker intermediates binding and enhanced ORR activity.展开更多
Tremendous efforts have been devoted to explore energy-efficient strategies of ammonia synthesis to replace Haber-Bosch process which accounts for 1.4% of the annual energy consumption. In this study, atomically dispe...Tremendous efforts have been devoted to explore energy-efficient strategies of ammonia synthesis to replace Haber-Bosch process which accounts for 1.4% of the annual energy consumption. In this study, atomically dispersed Au_1 catalyst is synthesized and applied in electrochemical synthesis of ammonia under ambient conditions. A high NH＋4 Faradaic efficiency of 11.1 % achieved by our Au_1 catalyst surpasses most of reported catalysts under comparable conditions. Benefiting from efficient atom utilization, an NH＋4 yield rate of 1,305 μg h-1 mg-1Au has been reached, which is roughly 22.5 times as high as that by sup- ported Au nanoparticles. We also demonstrate that by employing our Au_1 catalyst, NH＋4 can be electro- chemically produced directly from N_2 and H_2 with an energy utilization rate of 4.02 mmol kJ-1. Our study provides a possibility of replacing the Haber-Bosch process with environmentally benign and energy-efficient electrochemical strategies.展开更多
In catalysis,tuning the structural composition of the metal alloy is known as an efficient way to optimize the catalytic activity.This work presents the synthesis of compositional segregated six-armed PtCu nanostars v...In catalysis,tuning the structural composition of the metal alloy is known as an efficient way to optimize the catalytic activity.This work presents the synthesis of compositional segregated six-armed PtCu nanostars via a facile solvothermal method and their distinct composition-structure-dependent performances in electrooxidation processes.The alloy is shown to have a unique six arms with a Cu-rich dodecahedral core,mainly composed of {110} facets and exhibit superior catalytic activity toward alcohols electrooxidation compared to the hollow counterpart where Cu was selectively etched.Density functional theory (DFT) calculations suggest that the formation of hydroxyl intermediate (OH^*) is crucial to detoxify CO poisoning during the electrooxidation processes.The addition of Cu is found to effectively adjust the d band location of the alloy catalyst and thus enhance the formation of ^*OH intermediate from water splitting,which decreases the coverage of ^*CO intermediate.Our work demonstrates that the unique compositional anisotropy in alloy catalyst may boost their applications in electrocatalysis and provides a methodology for the design of this type catalyst.展开更多
The activity and stability of Cu nanostructures strongly depend on their sizes,morphology and structures.Here we report the preparation of two-dimensional(2 D)Cu@Cu-BTC core-shell nanosheets(NSs).The thickness of the ...The activity and stability of Cu nanostructures strongly depend on their sizes,morphology and structures.Here we report the preparation of two-dimensional(2 D)Cu@Cu-BTC core-shell nanosheets(NSs).The thickness of the Cu NSs could be tuned to sub-10 nm through a mild etching process,in which the Cu-BTC in situ grow along with the oxidation on the surface of the Cu NSs.This unique strategy can also be extended to synthesize one-dimensional(1 D)Cu@Cu-BTC nanowires(NWs).Furthermore,the obtained Cu@Cu-BTC NSs could be applied as an effective material to the memory device with the write-onceread-many times(WORM)behavior and the high ION/I(OFF)ratio(>2.7×103).展开更多
Engineering the local three-dimensional structure of metal sites has an important effect of maximizing the activity and selectivity of single-atom site catalysts.Here,we engineered a strain-assisted single Pt sites st...Engineering the local three-dimensional structure of metal sites has an important effect of maximizing the activity and selectivity of single-atom site catalysts.Here,we engineered a strain-assisted single Pt sites structure on a highly curved MoS_(2)surface to enhance its H_(2)S sensor property.By introducing N-methyl-2-pyrrolidone(NMP)as guiding molecules,a multilayer MoS_(2)structure with bending base planes was achieved.This bending behavior could inject not only uniform in-plane strain into the original inert MoS_(2)basal plane but also introduce sufficient accessible sites to anchor Pt monomers.Further experimental and theoretical results showed that the highcurvature MoS_(2)surface endowed 0.8%stretch strain onto the low-coordinated single Pt sites with a unique“tip”effect,which led to more accumulation of electrons around the Pt species,thereby accelerating the electric transfer process between H_(2)S and supports.The final catalyst delivered pronouncedly enhanced H_(2)S sensing response and response speed at room temperature.Our proposed strain-assisted strategy might create a new path to design highly active single-atom site catalysts for gas sensors.展开更多
文摘Research on two-dimensional(2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since the mechanical exfoliation of graphene in 2004. Starting from graphene, 2D materials now have become a big family with numerous members and diverse categories. The unique structural features and physicochemical properties of 2D materials make them one class of the most appealing candidates for a wide range of potential applications. In particular, we have seen some major breakthroughs made in the field of 2D materials in last five years not only in developing novel synthetic methods and exploring new structures/properties but also in identifying innovative applications and pushing forward commercialisation. In this review, we provide a critical summary on the recent progress made in the field of 2D materials with a particular focus on last five years. After a brief backgroundintroduction, we first discuss the major synthetic methods for 2D materials, including the mechanical exfoliation, liquid exfoliation, vapor phase deposition, and wet-chemical synthesis as well as phase engineering of 2D materials belonging to the field of phase engineering of nanomaterials(PEN). We then introduce the superconducting/optical/magnetic properties and chirality of 2D materials along with newly emerging magic angle 2D superlattices. Following that, the promising applications of 2D materials in electronics, optoelectronics, catalysis, energy storage, solar cells, biomedicine, sensors, environments, etc. are described sequentially. Thereafter, we present the theoretic calculations and simulations of 2D materials. Finally, after concluding the current progress, we provide some personal discussions on the existing challenges and future outlooks in this rapidly developing field.
基金Supported by the National Natural Science Foundation of China, No. 30271177 and No. 39870676 National 9th Five-year Program, No. 101033+3 种基金 Major Science and Technology Projects of Guangdong Province, No. B602 Natural Science Foundation of Guangdong Province, No. 021903 Postdoctoral Fellowship Foundation of China (Series 29) Special Fund of Scientific Instrument Collaborative Share-net in Guangzhou. No. 2006176
文摘AIM： To use the tyrosinase minigene as a visual marker to perform microinjection training and improve the techniques related with transgene to greatly elevate the effidency of gene transfer. METHODS： A mouse tyrosinase minigene, i.e., TyBS, in which the 2.25-kb authentic genomic 5＇ non-coding flanking sequence of mouse tyrosinase was fused to a mouse tyrosinase cDNA, was introduced into the fertilized eggs of outbred Kunming albino mice. RESULTS： Of the 11 animals that developed from the injected eggs, two mice （P1 and #8） exhibited pigmented hair （P1） and eyes （P1 and #8）, as confirmed by PCR analysis for the tyrosinase minigene integrated into the genome. When founder P1 was bred to Kunming male mouse, six progeny out of 11 offspring inherited the transgene and the pigmented-eye phenotype. CONCLUSION： Taken together, these results suggest that this minigene encodes the active tyrosinase protein and that its 5＇ flanking region contains the sequences regulating the expression of mouse tyrosinase gene as expected. We have rescued the albino phenotype by introduction and expression of a functional tyrosinase minigene in the Kunming albino mouse and the transgene can be passed to subsequent generation. These findings also indicate that TyBS can be a useful visual marker gene in the co-transgenic experiments.
基金The National Key Research and Development Program of China(Nos.2018YFA0702001 and 2021YFA1500400)the National Natural Science Foundation of China(Nos.22371268 and 22175163)+2 种基金Fundamental Research Funds for the Central Universities(No.WK2060000016)Anhui Development and Reform Commission(No.AHZDCYCX-2SDT2023-07)Youth Innovation Promotion Association of the Chinese Academy of Science(No.2018494)supported this work.
文摘IrRu bimetallic oxides are recognized as the promising acidic oxygen evolution reaction(OER)catalysts,but breaking the trade-off between their activity and stability is an unresolved question.Meanwhile,addressing the issues of mass transport obstruction of IrRu bimetallic oxides under high current remains a challenge for the development of proton exchange membrane water electrolysis(PEM-WE).Herein,we prepared an IrRuO_(x)nanomeshes(IrRuO_(x)NMs)with high coordination number(CN)of Ir-O-Ru bonds in a mixed molten salt with high solubility of the Ir/Ru precursor.X-ray absorption spectroscopy analysis revealed that the IrRuO_(x)NMs possess high coordination number of Ir-O-Ru bonds(CNIr-O-Ru=5.6)with a distance of 3.18Å.Moreover,the nanomesh structures of IrRuO_(x)NMs provided hierarchical channels to accelerate the transport of oxygen and water,thus further improving the electrochemical activity.Consequently,the IrRuO_(x)NMs as OER catalysts can simultaneously achieve high activity and stability with low overpotential of 196 mV to reach 10 mA·cm^(−2)and slightly increase by 70 mV over 650 h test.Differential electrochemical mass spectrometry tests suggest that the preferred OER mechanism for IrRuO_(x)NMs is the adsorbent evolution mechanism,which is beneficial for the robust structural stability.
基金supported by the National Key R&D Program of China(No.2018YFA0702001)the National Natural Science Foundation of China(Nos.22371268 and 22301287)+4 种基金Fundamental Research Funds for the Central Universities(No.WK2060000016)Anhui Provincial Natural Science Foundation(Nos.2208085J09 and 2208085QB33)Collaborative Innovation Program of Hefei Science Center,CAS(No.2022HSC-CIP020)Youth Innovation Promotion Association of the Chinese Academy of Science(No.2018494)USTC Tang Scholar.
文摘The electrochemical CO_(2) reduction reaction(CO_(2)RR)holds significant promise in advancing carbon neutrality.Developing catalysts for the electrochemical CO_(2)RR to multi-carbon(C_(2+))products(e.g.,C_(2)H_(4))under industrial-level current density is urgently needed and pivotal.Herein,we report the Cu_(2)O nanoparticles doped with interstitial carbon atoms(denoted as C-Cu_(2)O NPs)for the conversion of CO_(2) to C_(2+)products.The interstitial carbon promotes the C-Cu_(2)O NPs to possess abundant unsaturated Cu–O bonds,leading to a high-density Cu^(δ+)(0<δ<1)species.The obtained C-Cu_(2)O NPs exhibited significant Faradic efficiency(FE)of C_(2+) products approaching 76.9%and a partial current density reaching 615.2 mA·cm^(–2)under an industrial-level current density of 800 mA·cm^(–2).Furthermore,the efficient electrosynthesis of C_(2)H_(4) achieved an FE of 57.4%with a partial current density of 459.2 mA·cm^(–2).In situ electrochemical attenuated total reflection Fourier transform infrared spectroscopy and in situ Raman spectroscopy analyses revealed that C-Cu_(2)O NPs stabilized the intermediate*CO and facilitated C–C coupling,leading to increased selectivity towards C_(2+) products.
基金The National Key R&D Program of China(Nos.2018YFA0702001 and 2021YFA1500400)the National Natural Science Foundation of China(Nos.22371268 and 22175163)+2 种基金Fundamental Research Funds for the Central Universities(No.WK2060000016)Anhui Development and Reform Commission(No.AHZDCYCX-2SDT2023-07)Youth Innovation Promotion Association of the Chinese Academy of Science(No.2018494)supported this work.
文摘The efficiency of proton exchange membrane water electrolysis(PEM-WE)for hydrogen production is heavily dependent on the noble metal iridium-based catalysts.However,the scarcity of iridium limits the large-scale application of PEM-WE.To address this issue,it is promising to select an appropriate support because it not only enhances the utilization efficiency of noble metals but also improves mass transport under high current.Herein,we supported amorphous IrO_(x) nanosheets onto the hollow TiO_(2) sphere(denoted as IrO_(x)),which demonstrated excellent performance in acidic electrolytic water splitting.Specifically,the annealed IrO_(x)catalyst at 150℃in air exhibited a mass activity of 1347.5 A·gIr^(−1),which is much higher than that of commercial IrO_(2) of 12.33 A·gIr^(−1) at the overpotential of 300 mV for oxygen evolution reaction(OER).Meanwhile,the annealed IrO_(x) exhibited good stability for 600 h operating at 10 mA·cm^(−2).Moreover,when using IrO_(x) and annealed IrO_(x) catalysts for water splitting,a cell voltage as low as 1.485 V can be achieved at 10 mA·cm^(−2).The cell can continuously operate for 200 h with negligible degradation of performance.
基金Anhui Province for Outstanding Youth,Grant/Award Number:2208085J09Anhui Development and Reform Commission,Grant/Award Number:AHZDCYCX-2SDT2023-07+7 种基金National Key R&D Program of China,Grant/Award Number:2018YFA0702001Postdoctoral Fellowship Program of CPSF,Grant/Award Number:GZC20232511USTC Tang ScholarYouth Innovation Promotion Association of the Chinese Academy of Science,Grant/Award Number:2018494Fundamental Research Funds for the Central Universities,Grant/Award Number:WK2060000016Collaborative Innovation Program of Hefei Science Center,CAS,Grant/Award Number:2022HSC-CIP020National Natural Science Foundation of China,Grant/Award Numbers:22301287,22371268China Postdoctoral Science Foundation,Grant/Award Number:2023M743348。
文摘To unveil the nature of amorphous states,single-element amorphous metals have been the perfect research subject due to the simplest composition.However,the extreme crystal nucleation and growth rate in single-element metal make the synthesis of single-element amorphous metals seemingly impossible in the past.Fortunately,benefited by several delicate synthetic strategies developed recently,the single-element amorphous metals have been successfully demonstrated.This review aims to provide a systematic overview of the synthesis of single-element amorphous metals covering the challenges in physics and recent achieve-ments.In addition,current understanding of the atomic and electronic structures of single-element amorphous metal has also been included.Finally,the challenges that worth further investigation are discussed.By identifying the potential avenues for further exploration,this review aims to contribute valuable insights that will propel the cognition of single-element amorphous metals.
基金supported by the National Key R&D Program of China(Nos.2017YFA0700104 and 2018YFA0702001)the National Natural Science Foundation of China(Nos.21871238 and 22175163)+1 种基金the Fundamental Research Funds for the Central Universities(No.WK2060000016)the Youth Innovation Promotion Association of the Chinese Academy of Science(No.2018494).
文摘Manipulating the oxidation state of Cu catalysts can significantly affect the selectivity and activity of electrocatalytic carbon dioxide reduction(CO_(2)RR).However,the thermodynamically favorable cathodic reduction to metallic states typically leads to catalytic deactivation.Herein,a defect construction strategy is employed to prepare crystalline/amorphous Cu_(2+1)O/CuO_(x)heterostructures(c/a-CuO_(x))with abundant Cu0 and Cuδ+(0<δ<1)sites for CO_(2)RR.The C^(2+)Faradaic efficiency of the heterostructured Cu catalyst is up to 81.3%,with partial current densities of 406.7 mA·cm−2.Significantly,real-time monitoring of the Cu oxidation state evolution by in-situ Raman spectroscopy confirms the stability of Cuδ+species under long-term high current density operation.Density functional theory(DFT)calculations further reveal that the adjacent Cu0 and Cuδ+sites in heterostructured c/a-CuO_(x)can efficiently reduce the energy barrier of CO coupling for C^(2+)products.
基金supported by the National Key R&D Program of China(Nos.2017YFA0700104 and 2018YFA0702001)the National Natural Science Foundation of China(No.21871238)+2 种基金the Fundamental Research Funds for the Central Universities(No.WK2060000016)the Youth Innovation Promotion Association of the Chinese Academy of Science(No.2018494)the Hefei National Laboratory for Physical Sciences at the Microscale(No.KF2020107).
文摘Highly efficient and stable oxygen reduction reaction(ORR)electrocatalysts are remarkably important but challenging for advancing the large-scale commercialization of practical proton exchange membrane fuel cells(PEMFCs).In this work,we report that the introduction of interstitial hydrogen atoms into PtPd nanotubes can significantly promote ORR performance without scarifying the durability.The enhanced mass activity was 8.8 times higher than that of commercial Pt/C.The accelerated durability test showed negligible activity attenuation after 30,000 cycles.Additionally,H2/O2 fuel cell tests further verified the excellent activity of PtPd-H nanotubes with a maximum power density of 1.32 W·cm^(−2),superior to that of commercial Pt/C(1.16 W·cm^(−2)).Density functional theory calculations demonstrated the incorporation of hydrogen atoms gives rise to the broadening of Pt d-band and the downshift of d-band center,which consequently leads to the weaker intermediates binding and enhanced ORR activity.
基金supported by the National Key R&D Program of China (2017YFA0208300)the National Natural Science Foundation of China (21522107, 21671180, 21521091, 21390393, U1463202, and 21522305)
文摘Tremendous efforts have been devoted to explore energy-efficient strategies of ammonia synthesis to replace Haber-Bosch process which accounts for 1.4% of the annual energy consumption. In this study, atomically dispersed Au_1 catalyst is synthesized and applied in electrochemical synthesis of ammonia under ambient conditions. A high NH＋4 Faradaic efficiency of 11.1 % achieved by our Au_1 catalyst surpasses most of reported catalysts under comparable conditions. Benefiting from efficient atom utilization, an NH＋4 yield rate of 1,305 μg h-1 mg-1Au has been reached, which is roughly 22.5 times as high as that by sup- ported Au nanoparticles. We also demonstrate that by employing our Au_1 catalyst, NH＋4 can be electro- chemically produced directly from N_2 and H_2 with an energy utilization rate of 4.02 mmol kJ-1. Our study provides a possibility of replacing the Haber-Bosch process with environmentally benign and energy-efficient electrochemical strategies.
基金the support from National Natural Science Foundation of China (Nos.21571001,21372006,21631001,and U1532141)the Ministry of Education, the Education Department of Anhui Province211 Project of Anhui University.Y G.W gratefully acknowledges the financial support from Southern University of Science and Technolgoy (SUSTech). The calculations were performed by using the Taiyi high-performance supercomputer cluster located at SUSTech.
文摘In catalysis,tuning the structural composition of the metal alloy is known as an efficient way to optimize the catalytic activity.This work presents the synthesis of compositional segregated six-armed PtCu nanostars via a facile solvothermal method and their distinct composition-structure-dependent performances in electrooxidation processes.The alloy is shown to have a unique six arms with a Cu-rich dodecahedral core,mainly composed of {110} facets and exhibit superior catalytic activity toward alcohols electrooxidation compared to the hollow counterpart where Cu was selectively etched.Density functional theory (DFT) calculations suggest that the formation of hydroxyl intermediate (OH^*) is crucial to detoxify CO poisoning during the electrooxidation processes.The addition of Cu is found to effectively adjust the d band location of the alloy catalyst and thus enhance the formation of ^*OH intermediate from water splitting,which decreases the coverage of ^*CO intermediate.Our work demonstrates that the unique compositional anisotropy in alloy catalyst may boost their applications in electrocatalysis and provides a methodology for the design of this type catalyst.
基金supported by the National Key R&D Program of China(No.2017YFA0700104)National Natural Science Foundation of China(Nos.21571169,21871238)+2 种基金Fundamental Research Funds for the Central Universities(No.WK2060190081)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2018494)Young Elite Scientists Sponsorship Program by CAST(No.2016QNRC001)
文摘The activity and stability of Cu nanostructures strongly depend on their sizes,morphology and structures.Here we report the preparation of two-dimensional(2 D)Cu@Cu-BTC core-shell nanosheets(NSs).The thickness of the Cu NSs could be tuned to sub-10 nm through a mild etching process,in which the Cu-BTC in situ grow along with the oxidation on the surface of the Cu NSs.This unique strategy can also be extended to synthesize one-dimensional(1 D)Cu@Cu-BTC nanowires(NWs).Furthermore,the obtained Cu@Cu-BTC NSs could be applied as an effective material to the memory device with the write-onceread-many times(WORM)behavior and the high ION/I(OFF)ratio(>2.7×103).
基金This work was supported by the China Ministry of Science and Technology(grant no.2020YFA0710200)National Key R&D Program of China 2017YFA(grant nos.0208300 and 0700104)+2 种基金the National Natural Science Foundation of China(grant no.21671180)the Dalian National Laboratory for Clean Energy(DNL)Cooperation Fund,CAS(grant no.DNL201918)the Fundamental Research Funds for the Central Universities(grant nos.WK2060120004,WK2060000021,WK2060000025,and KY2060000180).
文摘Engineering the local three-dimensional structure of metal sites has an important effect of maximizing the activity and selectivity of single-atom site catalysts.Here,we engineered a strain-assisted single Pt sites structure on a highly curved MoS_(2)surface to enhance its H_(2)S sensor property.By introducing N-methyl-2-pyrrolidone(NMP)as guiding molecules,a multilayer MoS_(2)structure with bending base planes was achieved.This bending behavior could inject not only uniform in-plane strain into the original inert MoS_(2)basal plane but also introduce sufficient accessible sites to anchor Pt monomers.Further experimental and theoretical results showed that the highcurvature MoS_(2)surface endowed 0.8%stretch strain onto the low-coordinated single Pt sites with a unique“tip”effect,which led to more accumulation of electrons around the Pt species,thereby accelerating the electric transfer process between H_(2)S and supports.The final catalyst delivered pronouncedly enhanced H_(2)S sensing response and response speed at room temperature.Our proposed strain-assisted strategy might create a new path to design highly active single-atom site catalysts for gas sensors.
