We investigated the relationship between oxygen reduction reaction(ORR)activity and the pyrolysis temperature(650-850℃)of CuPc in alkaline solution.The highly active sites were formed through the decomposition of CuP...We investigated the relationship between oxygen reduction reaction(ORR)activity and the pyrolysis temperature(650-850℃)of CuPc in alkaline solution.The highly active sites were formed through the decomposition of CuPc or Cu-N_(4) structure after releasing 4-nitrophthalonitrile.Cu-Nx incorporated with carbon were the main active sites.The XPS measurement results show that,at lower temperature,the contents of pyridinic-N and pyrrolic-N account for the most of the total N.As the temperature is higher than 750℃,the content of graphitic N(26.11%)increases and pyridinic-N(58.81%)becomes the dominant specie.When the temperature is higher than 850℃,the content of graphitic N increases remarkably and becomes the dominant species.Moreover,the specific surface areas decrease with increased pyrolysis temperature.Benefiting from the synergistic effect,the pyrolysis temperature at 750℃of CuPc displays superior electrocatalytic properties.The obtained results reveal that the fabricated non-noble metal catalysts can be used as low-cost,efficient catalyst for water splitting ORR in metal-air batteries and fuel cells.展开更多
The quantitative understanding of how atomic-level catalyst structural changes affect the reactivity of the electrochemical CO_(2)reduction reaction is challenging.Due to the complexity of catalytic systems,convention...The quantitative understanding of how atomic-level catalyst structural changes affect the reactivity of the electrochemical CO_(2)reduction reaction is challenging.Due to the complexity of catalytic systems,conventional in situ X-ray spectroscopy plays a limited role in tracing the underlying dynamic structural changes in catalysts active sites.Herein,operando high-energy resolution fluorescence-detected X-ray absorption spectroscopy was used to precisely identify the dynamic structural transformation of well-defined active sites of a representative model copper(Ⅱ)phthalocyanine catalyst which is of guiding significance in studying single-atom catalysis system.Comprehensive X-ray spectroscopy analyses,including surface sensitive△μspectra which isolates the surface changes by subtracting the disturb of bulk base and X-ray absorption near-edge structure spectroscopy simulation,were used to discover that Cu species aggregated with increasing applied potential,which is responsible for the observed evolution of C_(2)H_(4).The approach developed in this work,characterizing the active-site geometry and dynamic structural change,is a novel and powerful technique to elucidate complex catalytic mechanisms and is expected to con tribute to the rational design of highly effective catalysts.展开更多
Efficient heterojunction organic photovoltaic （OPV） cells are fabricated based on copper tetra-methyl phthalocyanine （CuMePc） as donor and fullerene （C60） as acceptor. The power conversion efficiency of CuMePc/C...Efficient heterojunction organic photovoltaic （OPV） cells are fabricated based on copper tetra-methyl phthalocyanine （CuMePc） as donor and fullerene （C60） as acceptor. The power conversion efficiency of CuMePc/C60 OPV cell （2.52%） is increased by 88% compared with that of the non-peripheral substituted copper phthalocyanine （CuPc）/C60 OPV cell （1.34%）. The introduction of methyl substituent leads to stronger π–π interaction of CuMePc （～ 3.5 ？） than that of CuPc （～ 3.8 ？）. The efficiency improvement is attributed to the enhanced carrier mobility of CuMePc thin film （1.1×10-3 cm2/V·s） and better film morphology by introducing methyl groups into the periphery of CuPc molecule.展开更多
Direct electrochemical nitrate reduction reaction(NITRR)is a promising strategy to alleviate the unbalanced nitrogen cycle while achieving the electrosynthesis of ammonia.However,the restructuration of the high-activi...Direct electrochemical nitrate reduction reaction(NITRR)is a promising strategy to alleviate the unbalanced nitrogen cycle while achieving the electrosynthesis of ammonia.However,the restructuration of the high-activity Cu-based electrocatalysts in the NITRR process has hindered the identification of dynamical active sites and in-depth investigation of the catalytic mechanism.Herein,Cu species(single-atom,clusters,and nanoparticles)with tunable loading supported on N-doped TiO_(2)/C are successfully manufactured with MOFs@CuPc precursors via the pre-anchor and post-pyrolysis strategy.Restructuration behavior among Cu species is co-dependent on the Cu loading and reaction potential,as evidenced by the advanced operando X-ray absorption spectroscopy,and there exists an incompletely reversible transformation of the restructured structure to the initial state.Notably,restructured CuN_(4)&Cu_(4) deliver the high NH_(3) yield of 88.2 mmol h^(−1)g_(cata)^(−1) and FE(~94.3%)at−0.75 V,resulting from the optimal adsorption of NO_(3)^(−) as well as the rapid conversion of^(*)NH_(2)OH to^(*)NH_(2) intermediates originated from the modulation of charge distribution and d-band center for Cu site.This work not only uncovers CuN_(4)&Cu_(4) have the promising NITRR but also identifies the dynamic Cu species active sites that play a critical role in the efficient electrocatalytic reduction in nitrate to ammonia.展开更多
Copper phthalocyanine junctions, fabricated by magnetron sputtering and evaporating methods, show multi-polar （unipolar and bipolar） resistance switching and the memory effect. The multi-polar resistance switching h...Copper phthalocyanine junctions, fabricated by magnetron sputtering and evaporating methods, show multi-polar （unipolar and bipolar） resistance switching and the memory effect. The multi-polar resistance switching has not been observed simultaneously in one organic material before. With both electrodes being cobalt, the unipolar resistance switching is universal. The high resistance state is switched to the low resistance state when the bias reaches the set voltage. Generally, the set voltage increases with the thickness of copper phthalocyanine and decreases with increasing dwell time of bias. Moreover, the low resistance state could be switched to the high resistance state by absorbing the phonon energy. The stability of the low resistance state could be tuned by different electrodes. In Au/copper phthalocyanine/Co system, the low resistance state is far more stable, and the bipolar resistance switching is found. Temperature dependence of electrical transport measurements demonstrates that there are no obvious differences in the electrical transport mechanism before and after the resistance switching. They fit quite well with Mott variable range hopping theory. The effect of A1203 on the resistance switching is excluded by control experiments. The holes trapping and detrapping in copper phthalocyanine layer are responsible for the resistance switching, and the interfacial effect between electrodes and copper phthalocyanine layer affects the memory effect.展开更多
The creation of Au/CuPe/Al/CuPc/strueture is a perpendicular type electricity found in the channel of organic static induction transistor. In the following we analyze transistor operation characteristics and machine s...The creation of Au/CuPe/Al/CuPc/strueture is a perpendicular type electricity found in the channel of organic static induction transistor. In the following we analyze transistor operation characteristics and machine structural relation. The results express that the transistor drives the voltage low and has no-saturation currentvoltage characteristics. Its operation characteristics are dependant on gate bias voltage and the construction of the aluminum eleetrode. The vertical ehannel of organic static induction transistor （OSIT） , with structure of Au/CuPc/Al/CuPc/ Cu, has been determined. According to the test results, the relation of its operation characteristics aud device structure was analyzed. The results show that this transistor has a low driving voltage and unsaturation Ⅰ-Ⅴ characteristies. Its operation characteristics are dependant on gate bias voltage and the structure of the aluminum electrode.展开更多
Langmuir-Blodgett(LB)films of tetra-nonyl phthalocyanine copper (TNPcCu)were prepared.Molecular arrangement and orientation of these films were studied in detail.LB multilayer films of TNPcCu show a very Strong x-ray ...Langmuir-Blodgett(LB)films of tetra-nonyl phthalocyanine copper (TNPcCu)were prepared.Molecular arrangement and orientation of these films were studied in detail.LB multilayer films of TNPcCu show a very Strong x-ray diffration peak and two weak peaks which indicate that the LB films form a quasi-crystal structure which molecules are arranged orderly.IR reflection absorption spectra and polarized VIS absorption spectra not only confirm the previous result but also indicate that phthalocyanine rings orient nearly perpendicular to the substrate surface and perpendicular to the lifting direction and the side-chain segments are not preferred oriented.展开更多
Infrared spectra of alternating LB films of octadecyl-TCNQ/CuPc are studied. Charge-transfer complexes are formed in LB films and conductance increases about three orders than that of pure CuPc LB films.
The surface photovoltaic characteristic of copper tetrasulfonato- phthalocyanine (CuTsPc) in water vapor was studied by surface photovoltage spectroscopy (SPS). It was found that the adsorption of water vapor caused s...The surface photovoltaic characteristic of copper tetrasulfonato- phthalocyanine (CuTsPc) in water vapor was studied by surface photovoltage spectroscopy (SPS). It was found that the adsorption of water vapor caused some marvelous changes of the photovoltaic response, that is, the SPS signal diminished rapidly and even reversed; the bands were widened and displayed a bathochromic shift. The dependence of surface photovoltage on the vapor pressure indicates that the reversed signal reaches to a maximum when the vapor pressure is 4.7×102 Pa. The time response velocity, reversibility, selectivity and reproducibili-ty were examined as well. All results obtained show that CuTsPc is of great significance in the manufacture of moisture sensitive devices. In addition, the mechanism of moisture sensitivity is discussed.展开更多
Copper phthalocyanine(CuPc)is adopted as an electrolyte additive to stabilize lithium anode for lithiumsulfur(Li-S)batteries.CuPc with a planar molecular structure and lithiophilic N-containing group,is likely to be a...Copper phthalocyanine(CuPc)is adopted as an electrolyte additive to stabilize lithium anode for lithiumsulfur(Li-S)batteries.CuPc with a planar molecular structure and lithiophilic N-containing group,is likely to be adsorbed on the surface of Li anode to form a coating layer,which can restrict the direct contact between Li anode and solvents,and guide the uniform deposition of Li^(+)ions.The Li||Li symmetric cells demonstrate a stable cycle performance,and Li||Cu cells show high Coulombic efficiencies.In Li-S batteries,the formed stable solid-electrolyte interface(SEI)film containing copper sulfides can protect Li anode from the polysulfide corrosion and side reactions with the electrolyte,leading to the compact and smooth surface morphology of Li anode.Therefore,the Li-S batteries with CuPc additive deliver much higher capacity,better cycle performance and rate capability as compared to the one without CuPc additive.展开更多
The azaanalog of copper phthalocyanine（azaCuPc） complex C 24H 8CuN 16 was prepared by the so- lid phase synthesis technology and its single crystals was characterized by high power Xray from the synchrotron radi...The azaanalog of copper phthalocyanine（azaCuPc） complex C 24H 8CuN 16 was prepared by the so- lid phase synthesis technology and its single crystals was characterized by high power Xray from the synchrotron radiation. The crystal belongs to monoclinic system, space group P21/n with a=1.612 3（3） nm, b= 0.529 40（11） nm, c=1.906 4（4） nm, β=105.25（3）°, V=1.569 9（5） nm, Z=2, Mr=584.00, Dc=1.235 g/cm3, F（000）=586, the final R=0.063 1 and wR=0.153 9 for 757 observed reflections with I>2σ（I）, GOF=1.340.展开更多
基金Funded by the National Natural Science Foundation of China(No.51521061)and“111”Project(No.B08040)。
文摘We investigated the relationship between oxygen reduction reaction(ORR)activity and the pyrolysis temperature(650-850℃)of CuPc in alkaline solution.The highly active sites were formed through the decomposition of CuPc or Cu-N_(4) structure after releasing 4-nitrophthalonitrile.Cu-Nx incorporated with carbon were the main active sites.The XPS measurement results show that,at lower temperature,the contents of pyridinic-N and pyrrolic-N account for the most of the total N.As the temperature is higher than 750℃,the content of graphitic N(26.11%)increases and pyridinic-N(58.81%)becomes the dominant specie.When the temperature is higher than 850℃,the content of graphitic N increases remarkably and becomes the dominant species.Moreover,the specific surface areas decrease with increased pyrolysis temperature.Benefiting from the synergistic effect,the pyrolysis temperature at 750℃of CuPc displays superior electrocatalytic properties.The obtained results reveal that the fabricated non-noble metal catalysts can be used as low-cost,efficient catalyst for water splitting ORR in metal-air batteries and fuel cells.
基金supported by the National Natural Science Foundation of China,grant number:U1732267.
文摘The quantitative understanding of how atomic-level catalyst structural changes affect the reactivity of the electrochemical CO_(2)reduction reaction is challenging.Due to the complexity of catalytic systems,conventional in situ X-ray spectroscopy plays a limited role in tracing the underlying dynamic structural changes in catalysts active sites.Herein,operando high-energy resolution fluorescence-detected X-ray absorption spectroscopy was used to precisely identify the dynamic structural transformation of well-defined active sites of a representative model copper(Ⅱ)phthalocyanine catalyst which is of guiding significance in studying single-atom catalysis system.Comprehensive X-ray spectroscopy analyses,including surface sensitive△μspectra which isolates the surface changes by subtracting the disturb of bulk base and X-ray absorption near-edge structure spectroscopy simulation,were used to discover that Cu species aggregated with increasing applied potential,which is responsible for the observed evolution of C_(2)H_(4).The approach developed in this work,characterizing the active-site geometry and dynamic structural change,is a novel and powerful technique to elucidate complex catalytic mechanisms and is expected to con tribute to the rational design of highly effective catalysts.
基金Project supported by the Special Funds for the Development of Strategic Emerging Industries in Shenzhen City,China(Grant No.JCYJ20120830154526537)Start-up Funding of the South University of Science and Technology of China,and the Strategic Research Grant of the City University of Hong Kong(Grant No.7002724)
文摘Efficient heterojunction organic photovoltaic （OPV） cells are fabricated based on copper tetra-methyl phthalocyanine （CuMePc） as donor and fullerene （C60） as acceptor. The power conversion efficiency of CuMePc/C60 OPV cell （2.52%） is increased by 88% compared with that of the non-peripheral substituted copper phthalocyanine （CuPc）/C60 OPV cell （1.34%）. The introduction of methyl substituent leads to stronger π–π interaction of CuMePc （～ 3.5 ？） than that of CuPc （～ 3.8 ？）. The efficiency improvement is attributed to the enhanced carrier mobility of CuMePc thin film （1.1×10-3 cm2/V·s） and better film morphology by introducing methyl groups into the periphery of CuPc molecule.
基金supported by the National Natural Science Foundation of China(Grant numbers 92061106 and 21971016).
文摘Direct electrochemical nitrate reduction reaction(NITRR)is a promising strategy to alleviate the unbalanced nitrogen cycle while achieving the electrosynthesis of ammonia.However,the restructuration of the high-activity Cu-based electrocatalysts in the NITRR process has hindered the identification of dynamical active sites and in-depth investigation of the catalytic mechanism.Herein,Cu species(single-atom,clusters,and nanoparticles)with tunable loading supported on N-doped TiO_(2)/C are successfully manufactured with MOFs@CuPc precursors via the pre-anchor and post-pyrolysis strategy.Restructuration behavior among Cu species is co-dependent on the Cu loading and reaction potential,as evidenced by the advanced operando X-ray absorption spectroscopy,and there exists an incompletely reversible transformation of the restructured structure to the initial state.Notably,restructured CuN_(4)&Cu_(4) deliver the high NH_(3) yield of 88.2 mmol h^(−1)g_(cata)^(−1) and FE(~94.3%)at−0.75 V,resulting from the optimal adsorption of NO_(3)^(−) as well as the rapid conversion of^(*)NH_(2)OH to^(*)NH_(2) intermediates originated from the modulation of charge distribution and d-band center for Cu site.This work not only uncovers CuN_(4)&Cu_(4) have the promising NITRR but also identifies the dynamic Cu species active sites that play a critical role in the efficient electrocatalytic reduction in nitrate to ammonia.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.50971080,11174183,and 50901043)the Program for New Century Excellent Talents of China(Grant No.NCET-10-0541)+3 种基金the Scientific Research Foundation for Returned Overseas Chinese Scholars,111 Project(Grant No.B13029)the Natural Science Foundation of Shandong Province,China(Grant No.JQ201201)the Doctorate Foundation of Shandong Province,China(Grant No.BS2013CL042)the Young Scientists Fund of the National Natural Science Foundation of China(Grant No.11204164)
文摘Copper phthalocyanine junctions, fabricated by magnetron sputtering and evaporating methods, show multi-polar （unipolar and bipolar） resistance switching and the memory effect. The multi-polar resistance switching has not been observed simultaneously in one organic material before. With both electrodes being cobalt, the unipolar resistance switching is universal. The high resistance state is switched to the low resistance state when the bias reaches the set voltage. Generally, the set voltage increases with the thickness of copper phthalocyanine and decreases with increasing dwell time of bias. Moreover, the low resistance state could be switched to the high resistance state by absorbing the phonon energy. The stability of the low resistance state could be tuned by different electrodes. In Au/copper phthalocyanine/Co system, the low resistance state is far more stable, and the bipolar resistance switching is found. Temperature dependence of electrical transport measurements demonstrates that there are no obvious differences in the electrical transport mechanism before and after the resistance switching. They fit quite well with Mott variable range hopping theory. The effect of A1203 on the resistance switching is excluded by control experiments. The holes trapping and detrapping in copper phthalocyanine layer are responsible for the resistance switching, and the interfacial effect between electrodes and copper phthalocyanine layer affects the memory effect.
文摘The creation of Au/CuPe/Al/CuPc/strueture is a perpendicular type electricity found in the channel of organic static induction transistor. In the following we analyze transistor operation characteristics and machine structural relation. The results express that the transistor drives the voltage low and has no-saturation currentvoltage characteristics. Its operation characteristics are dependant on gate bias voltage and the construction of the aluminum eleetrode. The vertical ehannel of organic static induction transistor （OSIT） , with structure of Au/CuPc/Al/CuPc/ Cu, has been determined. According to the test results, the relation of its operation characteristics aud device structure was analyzed. The results show that this transistor has a low driving voltage and unsaturation Ⅰ-Ⅴ characteristies. Its operation characteristics are dependant on gate bias voltage and the structure of the aluminum electrode.
文摘Langmuir-Blodgett(LB)films of tetra-nonyl phthalocyanine copper (TNPcCu)were prepared.Molecular arrangement and orientation of these films were studied in detail.LB multilayer films of TNPcCu show a very Strong x-ray diffration peak and two weak peaks which indicate that the LB films form a quasi-crystal structure which molecules are arranged orderly.IR reflection absorption spectra and polarized VIS absorption spectra not only confirm the previous result but also indicate that phthalocyanine rings orient nearly perpendicular to the substrate surface and perpendicular to the lifting direction and the side-chain segments are not preferred oriented.
文摘Infrared spectra of alternating LB films of octadecyl-TCNQ/CuPc are studied. Charge-transfer complexes are formed in LB films and conductance increases about three orders than that of pure CuPc LB films.
基金Supported by the National Natural Science Foundation of China
文摘The surface photovoltaic characteristic of copper tetrasulfonato- phthalocyanine (CuTsPc) in water vapor was studied by surface photovoltage spectroscopy (SPS). It was found that the adsorption of water vapor caused some marvelous changes of the photovoltaic response, that is, the SPS signal diminished rapidly and even reversed; the bands were widened and displayed a bathochromic shift. The dependence of surface photovoltage on the vapor pressure indicates that the reversed signal reaches to a maximum when the vapor pressure is 4.7×102 Pa. The time response velocity, reversibility, selectivity and reproducibili-ty were examined as well. All results obtained show that CuTsPc is of great significance in the manufacture of moisture sensitive devices. In addition, the mechanism of moisture sensitivity is discussed.
基金supported by the National Natural Science Foundation of China(NSFC,Nos.22269013,22263009)the Natural Science Foundation of Jiangxi Province(Nos.20224ACB213001,20202ACB202004,20213BCJ22024,20212BBE53051)the Key Laboratory of Jiangxi Province for Environment and Energy Catalysis(No.20181BCD40004).
文摘Copper phthalocyanine(CuPc)is adopted as an electrolyte additive to stabilize lithium anode for lithiumsulfur(Li-S)batteries.CuPc with a planar molecular structure and lithiophilic N-containing group,is likely to be adsorbed on the surface of Li anode to form a coating layer,which can restrict the direct contact between Li anode and solvents,and guide the uniform deposition of Li^(+)ions.The Li||Li symmetric cells demonstrate a stable cycle performance,and Li||Cu cells show high Coulombic efficiencies.In Li-S batteries,the formed stable solid-electrolyte interface(SEI)film containing copper sulfides can protect Li anode from the polysulfide corrosion and side reactions with the electrolyte,leading to the compact and smooth surface morphology of Li anode.Therefore,the Li-S batteries with CuPc additive deliver much higher capacity,better cycle performance and rate capability as compared to the one without CuPc additive.
文摘The azaanalog of copper phthalocyanine（azaCuPc） complex C 24H 8CuN 16 was prepared by the so- lid phase synthesis technology and its single crystals was characterized by high power Xray from the synchrotron radiation. The crystal belongs to monoclinic system, space group P21/n with a=1.612 3（3） nm, b= 0.529 40（11） nm, c=1.906 4（4） nm, β=105.25（3）°, V=1.569 9（5） nm, Z=2, Mr=584.00, Dc=1.235 g/cm3, F（000）=586, the final R=0.063 1 and wR=0.153 9 for 757 observed reflections with I>2σ（I）, GOF=1.340.
