This paper aims to numerically investigate the rotating cavitation pressure pulsation and propagation characteristics of a three-bladed submerged pump inducer.First,the external and cavitation characteristics of the i...This paper aims to numerically investigate the rotating cavitation pressure pulsation and propagation characteristics of a three-bladed submerged pump inducer.First,the external and cavitation characteristics of the inducer in a normal-temperature water medium are studied experimentally.The accuracy of the numerical calculation model is then verified using the experimental results.On the basis of the numerical calculations,the pressure pulsation and rotational cavitation characteristics of the inducer of the submersible pump are analyzed.The results show that as the cavitation number decreases,the cavitation area in the inducer expands and shifts backward,affecting the inducer’s performance.The pressure pulsation amplitude increases,the frequency domain characteristics change,and the main frequency shifts from three times the shaft frequency to the same as the shaft frequency.The development of the cavitation zone and interaction between adjacent blades are key factors for the occurrence of rotational cavitation.The development of the cavitation zone is closely related to changes in the liquid flow angle.展开更多
Two missing cage isomers of C_(86)have been successfully stabilized by the encapsulation of the actinide ion Th.The two novel isomers of Th@C_(86)were synthesized using the arc-discharge method and characterized using...Two missing cage isomers of C_(86)have been successfully stabilized by the encapsulation of the actinide ion Th.The two novel isomers of Th@C_(86)were synthesized using the arc-discharge method and characterized using mass spectrometry,single-crystal X-ray crystallography,UV-vis-NIR spectroscopy and DFT calculations.The molecular structures of the two isomers were unambiguously assigned to Th@C_(2)(14)-C_(86)and Th@C_(3)(18)-C_(86)by crystallographic analysis.Both of these cage isomers of C_(86)have been predicted by computational studies but have never been experimentally confirmed until now.DFT computation reveals that both Th@C_(2)(14)-C_(86)and Th@C_(3)(18)-C_(86)present closed-shell electronic configurations with formally Th(Ⅳ),consistent with other previously reported Th based mono-metallofullerenes.Th@C_(2)(14)-C_(86)has emerged as the third lowest-energy isomer with significant predicted abundance at temperatures of fullerene formation.Th@C_(3)(18)-C_(86),on the other hand,represents an unexpected isomer with low thermodynamic stability,but significant abundance.Its formation was further rationalized as a kinetically trapped intermediate obtained from the lowest-energy and abundant Th@C_(2)(8)-C_(84),by a C_(2)insertion and a single Stone-Wales transformation.This study highlights the unique impact of actinides on the stabilization of fullerene cage isomers and also provides a more in-depth understanding into the stabilization mechanism of fullerene cage isomers.展开更多
Active carbon(AC)-supported AuCl_(3)catalysts are considered the most promising materials for acetylene hydrochlorination.However,there is no consensus on the reaction mechanism.In this paper,the mechanism and reactio...Active carbon(AC)-supported AuCl_(3)catalysts are considered the most promising materials for acetylene hydrochlorination.However,there is no consensus on the reaction mechanism.In this paper,the mechanism and reaction steps of Au_((I))-catalyzed acetylene hydrochlorination have been investigated by theoretical calculations.The results show that C_(2)H_(2)assists in the electrophilic addition of HCl,facilitating a change between the Au_((I))and Au_((III))redox couple.The linear structure of AuCl is proposed to form a tetracoordinated five-membered ring transition state,which is accompanied by the oxidation of Au from Au_((I))to Au_((III)).Besides,we explored and compared the reactivity and energy difference between Au_((III))-and Au_((I))-catalyzed acetylene hydrochlorination.The DFT calculations indicate that a strong combination between the Au center and ligands and the favorable hydrogen-transfer angle(close to 180°)significantly enhance the activity of the AuCl_(3)/AC catalyst.We also investigated the change from AuCl_(3)to AuCl,which suggests that the process of decomposition of AuCl_(3)to AuCl is highly possible.These understandings and explanations also open up an intriguing route to design a novel ligand,which is promising to maximize catalytic performance in acetylene hydrochlorination by increasing the stability of Au_((III))in the catalytic cycle.展开更多
Ligand engineering based on a closo-B_(12)-cage has been practiced in this work to design a series of stable gas-phase dianions[B_(12)(ECX)_(12)]^(2-)(E=N,P,and As;X=O,S,and Se)via ab initio calculations.The calculate...Ligand engineering based on a closo-B_(12)-cage has been practiced in this work to design a series of stable gas-phase dianions[B_(12)(ECX)_(12)]^(2-)(E=N,P,and As;X=O,S,and Se)via ab initio calculations.The calculated second electron affinities ranging from 1.2 to 3.4 eV indicate that these dianions are electronically stable against electron auto-detachment.Their electronic structures were analyzed based on molecular orbitals and natural bond orbitals.We found that in these designer dianions,the ECX ligands bind the B_(12)-cage via B-E covalent interactions.We simulated the photoelectron spectra of these dianions and discussed the potential application of[B_(12)(NCX)_(12)]^(2-)(X=O,S,and Se)salts as electrolytes in Li-or Mg-ion batteries.展开更多
The phonon dispersion and optical properties of mechanically exfoliated SnSSe were investigated with the aid of high-resolution Raman scattering and photoluminescence(PL)spectroscopies along with firstprinciples calcu...The phonon dispersion and optical properties of mechanically exfoliated SnSSe were investigated with the aid of high-resolution Raman scattering and photoluminescence(PL)spectroscopies along with firstprinciples calculations.The Raman modes indicate two-fold symmetry for in-plane vibrations and fourfold symmetry for out-of-plane vibrations.Consequently,the different polarization properties of the phonon modes demonstrate the anisotropic nature of SnSSe.The softening of Raman modes with the increase in temperature is described in terms of thermal expansion and anharmonic scattering,which contributes to phonon vibration,whereas a weak interlayer interaction in the SnSSe layers is observed.The significant suppression of PL signals at a higher temperature is related to the increase in the nonradiative recombination of electron–hole pairs as a result of the increment in the number of phonons and in the thermal excitation of carriers.In addition,the fabricated electrical device on few-layer SnSSe shows a significant ION/IOFF ratio and good electron mobility for optoelectronic applications.These results further improve the understanding of the microscopic details of SnSSe as an important material,providing better insights to control phonon propagation in thermoelectric,photovoltaic,and other materials to induce thermal management.展开更多
It is vital to search for efficient and stable oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)electrocatalysts for the development of metal–air batteries.Herein,we systematically investigated a serie...It is vital to search for efficient and stable oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)electrocatalysts for the development of metal–air batteries.Herein,we systematically investigated a series of TMN_(x)O_(4−x)-HTC(TM=Fe,Co,Ni,Ru,Rh,Pd,Ir and Pt;x=0–4;HTC=hexatribenzocyclyne)analogs of two-dimensional(2D)electrically conductive metal–organic frameworks(MOFs)as potential electrocatalysts for the OER and ORR by using density functional theory calculations.The calculated results exhibit good thermodynamic and electrochemical stabilities of the designed TMN_(x)O_(4−x)-HTC.The OER and ORR catalytic activity of the designed catalyst is governed by the interaction strength between the intermediates and the catalyst,and this interaction can be tuned by adjusting TM atoms and the local coordination number of N/O atoms.CoN_(3)O_(1)-HTC is found to be the best OER catalyst with an overpotential η^(OER) of 0.29 V,and RhN_(2)O_(2)-HTC exhibits the lowest ORR overpotentialηORR of 0.20 V.Importantly,RhO_(4)-HTC,RhN_(2)O_(2)-HTC and CoN1O_(3)-HTC are predicted as efficient bifunctional catalysts for the OER and ORR.Moreover,the kinetics simulation verifies the four-electron ORR pathway with high activity and selectivity toward H_(2)O production.The results not only contribute to designing and searching for efficient OER and ORR electrocatalysts but shed light on the opportunities to explore electrochemical applications based on 2D MOF materials.展开更多
A common feature of spin-crossover molecules deposited on a substrate is the presence of a residual proportion of high-spin(HS)molecules at low temperature,instead of the pure low-spin(LS)phase observed in the bulk.In...A common feature of spin-crossover molecules deposited on a substrate is the presence of a residual proportion of high-spin(HS)molecules at low temperature,instead of the pure low-spin(LS)phase observed in the bulk.In this work,we analyse by means of periodic rPBE calculations,the deposition of a monolayer of an Fe(Ⅱ)spin-crossover[Fe((3,5-(CH_(3))_(2)Pz)_(3)BH)_(2)]complex on a Au(111)substrate,with different proportions of HS/LS molecules.Our results indicate that there exist both thermodynamic and kinetic factors favoring the presence of a mixed HS/LS state at low temperature.The pure LS phase and a mixed spin state with 1/3 of HS molecules are close in energy,and the transition from this mixed spin state to the pure LS is hindered by the highest activation barrier in the transition from the HS to LS phase.The presence of the surrounding molecules of the 2D superstructure facilitates the transition from the LS to HS state and the interaction between the molecular layer and the surface increases with the proportion of HS molecules,in line with the epitaxial growth of the monolayer and its similarities with the(011¯)plane of the HS bulk molecular crystal.The density of states resulting from the rPBE calculations is used to simulate STM images.An excellent agreement is found between the simulated STM images for the mixed state with 1/3 of HS molecules and the images acquired at a constant height for a submonolayer of this Fe(Ⅱ)complex on Au(111).展开更多
In this work,the oxygen vacancy distributions in a 5 nm CeO_(2)nanocube were determined via Reverse Monte Carlo(RMC)simulations using neutron total scattering atomic pair distribution function(PDF)data,with further el...In this work,the oxygen vacancy distributions in a 5 nm CeO_(2)nanocube were determined via Reverse Monte Carlo(RMC)simulations using neutron total scattering atomic pair distribution function(PDF)data,with further elaboration based on DFT calculations.The results showed that the oxygen vacancies tend to be located towards the surface of the CeO_(2)nanocube,and the distribution rate of oxygen vacancies suddenly drops in the subsurface region and inside the nanocube.There are two types of vacancies on the subsurface,O_(vac)^(sub1)with a surface O atom above it and O_(vac)^(sub2)without a surface O atom above it,and the respective proportions are 61.9%and 38.1%.According to the DFT calculations,the remaining two 4f electrons,present on account of oxygen vacancy formation,preferably localize at 1N positions with respect to Ovac sur and O_(vac)^(sub2)or at 2N positions with respect to O_(vac)^(sub1).Furthermore,it could be concluded that the two excess electrons in the case of CeO_(2)(100)tend to stay in surface or subsurface Ce layers,according to the high proportion of longer characteristic Ce^(3+)–O bond lengths obtained from the Reverse Monte Carlo(RMC)simulations.It should be noted that type-1 subsurface oxygen vacancies,O_(vac)^(sub1),are expected to be more probable to aggregate,revealing the characteristic existence of accumulated subsurface vacancies.展开更多
Black phosphorene has been proposed as a high-efficiency metal-free two-dimensional photocatalyst for hydrogen production by visible light-driven water splitting.In this work,based on the screening of materials by den...Black phosphorene has been proposed as a high-efficiency metal-free two-dimensional photocatalyst for hydrogen production by visible light-driven water splitting.In this work,based on the screening of materials by density functional theory calculations,the potentials of group Ⅳ and group Ⅵ isoelectronic co-doped black phosphorenes(BPs)as candidate photocatalysts were comprehensively evaluated.According to the essential criteria of stability,electronic structure features,as well as visible light photocatalytic hydrogen production performance,we identified Si–S,Si–Se,Ge–S and Ge–Se co-doped BPs as promising catalysts.We highlighted that the isoelectronic co-doping process is geometrically and thermodynamically favorable.Interestingly,the isoelectronic co-dopants did not affect the direct and clean band gap nature of pure BP,and they also enhanced the photocatalytic hydrogen production properties,retaining a strong anisotropic feature.We believe that our findings will shed light on the modulation and development of BP based metal-free two-dimensional photocatalysts.展开更多
Fe-N-C catalysts represent the most promising class of platinum group metal-free(PGM-free)catalysts for the oxygen reduction reaction(ORR)in proton exchange membrane fuel cells(PEMFCs),exhibiting intrinsic activity po...Fe-N-C catalysts represent the most promising class of platinum group metal-free(PGM-free)catalysts for the oxygen reduction reaction(ORR)in proton exchange membrane fuel cells(PEMFCs),exhibiting intrinsic activity potentially competitive with commercial Pt/C benchmarks.However,critical challenges persist[1].As revealed by theoretical calculations,the enhancement of intrinsic activity in Fe-N-C catalysts is constrained by inherent scaling relations among the adsorption free energies of ORR intermediates on the catalyst surface.展开更多
基金co-supported by the National Science Fund for Distinguished Young Scholars of China(Grant No.52425903)the International Science and Technology Cooperation Program of Jiangsu Province(Grant No.BZ2024027).
文摘This paper aims to numerically investigate the rotating cavitation pressure pulsation and propagation characteristics of a three-bladed submerged pump inducer.First,the external and cavitation characteristics of the inducer in a normal-temperature water medium are studied experimentally.The accuracy of the numerical calculation model is then verified using the experimental results.On the basis of the numerical calculations,the pressure pulsation and rotational cavitation characteristics of the inducer of the submersible pump are analyzed.The results show that as the cavitation number decreases,the cavitation area in the inducer expands and shifts backward,affecting the inducer’s performance.The pressure pulsation amplitude increases,the frequency domain characteristics change,and the main frequency shifts from three times the shaft frequency to the same as the shaft frequency.The development of the cavitation zone and interaction between adjacent blades are key factors for the occurrence of rotational cavitation.The development of the cavitation zone is closely related to changes in the liquid flow angle.
基金National Natural Science Foundation of China(NSFC no.52172051)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)+1 种基金the Spanish Ministry of Science and Innovation(grant PID2020-112762GB-I00 funded by MCIN/AEI/10.13039/501100011033)the Generalitat de Catalunya(grant 2021SGR00110)and the URV for support.
文摘Two missing cage isomers of C_(86)have been successfully stabilized by the encapsulation of the actinide ion Th.The two novel isomers of Th@C_(86)were synthesized using the arc-discharge method and characterized using mass spectrometry,single-crystal X-ray crystallography,UV-vis-NIR spectroscopy and DFT calculations.The molecular structures of the two isomers were unambiguously assigned to Th@C_(2)(14)-C_(86)and Th@C_(3)(18)-C_(86)by crystallographic analysis.Both of these cage isomers of C_(86)have been predicted by computational studies but have never been experimentally confirmed until now.DFT computation reveals that both Th@C_(2)(14)-C_(86)and Th@C_(3)(18)-C_(86)present closed-shell electronic configurations with formally Th(Ⅳ),consistent with other previously reported Th based mono-metallofullerenes.Th@C_(2)(14)-C_(86)has emerged as the third lowest-energy isomer with significant predicted abundance at temperatures of fullerene formation.Th@C_(3)(18)-C_(86),on the other hand,represents an unexpected isomer with low thermodynamic stability,but significant abundance.Its formation was further rationalized as a kinetically trapped intermediate obtained from the lowest-energy and abundant Th@C_(2)(8)-C_(84),by a C_(2)insertion and a single Stone-Wales transformation.This study highlights the unique impact of actinides on the stabilization of fullerene cage isomers and also provides a more in-depth understanding into the stabilization mechanism of fullerene cage isomers.
基金supported by the National Natural Science Foundation of China(NSFC,21878162,21603107 and 21978137)dedicated to the 100th anniversary of Nankai University.
文摘Active carbon(AC)-supported AuCl_(3)catalysts are considered the most promising materials for acetylene hydrochlorination.However,there is no consensus on the reaction mechanism.In this paper,the mechanism and reaction steps of Au_((I))-catalyzed acetylene hydrochlorination have been investigated by theoretical calculations.The results show that C_(2)H_(2)assists in the electrophilic addition of HCl,facilitating a change between the Au_((I))and Au_((III))redox couple.The linear structure of AuCl is proposed to form a tetracoordinated five-membered ring transition state,which is accompanied by the oxidation of Au from Au_((I))to Au_((III)).Besides,we explored and compared the reactivity and energy difference between Au_((III))-and Au_((I))-catalyzed acetylene hydrochlorination.The DFT calculations indicate that a strong combination between the Au center and ligands and the favorable hydrogen-transfer angle(close to 180°)significantly enhance the activity of the AuCl_(3)/AC catalyst.We also investigated the change from AuCl_(3)to AuCl,which suggests that the process of decomposition of AuCl_(3)to AuCl is highly possible.These understandings and explanations also open up an intriguing route to design a novel ligand,which is promising to maximize catalytic performance in acetylene hydrochlorination by increasing the stability of Au_((III))in the catalytic cycle.
基金support from the National Key Research and Development Program(Grant No.2019YFA0210600)the National Natural Science Foundation of China(22003048,U1866203,92066207)the Natural Science Foundation of Shaanxi Province(2021JLM-27,2020JZ-03).
文摘Ligand engineering based on a closo-B_(12)-cage has been practiced in this work to design a series of stable gas-phase dianions[B_(12)(ECX)_(12)]^(2-)(E=N,P,and As;X=O,S,and Se)via ab initio calculations.The calculated second electron affinities ranging from 1.2 to 3.4 eV indicate that these dianions are electronically stable against electron auto-detachment.Their electronic structures were analyzed based on molecular orbitals and natural bond orbitals.We found that in these designer dianions,the ECX ligands bind the B_(12)-cage via B-E covalent interactions.We simulated the photoelectron spectra of these dianions and discussed the potential application of[B_(12)(NCX)_(12)]^(2-)(X=O,S,and Se)salts as electrolytes in Li-or Mg-ion batteries.
基金supported by the National Key R&D Program of China(2018YFC0910602)the National Natural Science Foundation of China(61775145/61525503/61620106016)+4 种基金Project of the Department of Education of Guangdong Province(2016KCXTD007)Shenzhen Basic Research Project(JCYJ20190808123401666/GJHZ20190822095420249/JCYJ20170412110212234)M.R.M.acknowledges Narodowe Centrum Nauki,Poland(2018/31/B/ST3/02111)M.I.acknowledge Scientific Research at King Khalid University,Saudi Arabia(R.G.P.21/318/42)Z.M.acknowledge Beihang Hefei Innovation Research Institute China(BHKX-19-02).
文摘The phonon dispersion and optical properties of mechanically exfoliated SnSSe were investigated with the aid of high-resolution Raman scattering and photoluminescence(PL)spectroscopies along with firstprinciples calculations.The Raman modes indicate two-fold symmetry for in-plane vibrations and fourfold symmetry for out-of-plane vibrations.Consequently,the different polarization properties of the phonon modes demonstrate the anisotropic nature of SnSSe.The softening of Raman modes with the increase in temperature is described in terms of thermal expansion and anharmonic scattering,which contributes to phonon vibration,whereas a weak interlayer interaction in the SnSSe layers is observed.The significant suppression of PL signals at a higher temperature is related to the increase in the nonradiative recombination of electron–hole pairs as a result of the increment in the number of phonons and in the thermal excitation of carriers.In addition,the fabricated electrical device on few-layer SnSSe shows a significant ION/IOFF ratio and good electron mobility for optoelectronic applications.These results further improve the understanding of the microscopic details of SnSSe as an important material,providing better insights to control phonon propagation in thermoelectric,photovoltaic,and other materials to induce thermal management.
基金supported by the National Natural Science Foundation of China(22102167 and U21A20317).
文摘It is vital to search for efficient and stable oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)electrocatalysts for the development of metal–air batteries.Herein,we systematically investigated a series of TMN_(x)O_(4−x)-HTC(TM=Fe,Co,Ni,Ru,Rh,Pd,Ir and Pt;x=0–4;HTC=hexatribenzocyclyne)analogs of two-dimensional(2D)electrically conductive metal–organic frameworks(MOFs)as potential electrocatalysts for the OER and ORR by using density functional theory calculations.The calculated results exhibit good thermodynamic and electrochemical stabilities of the designed TMN_(x)O_(4−x)-HTC.The OER and ORR catalytic activity of the designed catalyst is governed by the interaction strength between the intermediates and the catalyst,and this interaction can be tuned by adjusting TM atoms and the local coordination number of N/O atoms.CoN_(3)O_(1)-HTC is found to be the best OER catalyst with an overpotential η^(OER) of 0.29 V,and RhN_(2)O_(2)-HTC exhibits the lowest ORR overpotentialηORR of 0.20 V.Importantly,RhO_(4)-HTC,RhN_(2)O_(2)-HTC and CoN1O_(3)-HTC are predicted as efficient bifunctional catalysts for the OER and ORR.Moreover,the kinetics simulation verifies the four-electron ORR pathway with high activity and selectivity toward H_(2)O production.The results not only contribute to designing and searching for efficient OER and ORR electrocatalysts but shed light on the opportunities to explore electrochemical applications based on 2D MOF materials.
基金the financial support through grant PGC2018-101689-B-I00 funded by MCIN/AEI/10.13039/501100011033 and by“ERDF A way of making Europe”.
文摘A common feature of spin-crossover molecules deposited on a substrate is the presence of a residual proportion of high-spin(HS)molecules at low temperature,instead of the pure low-spin(LS)phase observed in the bulk.In this work,we analyse by means of periodic rPBE calculations,the deposition of a monolayer of an Fe(Ⅱ)spin-crossover[Fe((3,5-(CH_(3))_(2)Pz)_(3)BH)_(2)]complex on a Au(111)substrate,with different proportions of HS/LS molecules.Our results indicate that there exist both thermodynamic and kinetic factors favoring the presence of a mixed HS/LS state at low temperature.The pure LS phase and a mixed spin state with 1/3 of HS molecules are close in energy,and the transition from this mixed spin state to the pure LS is hindered by the highest activation barrier in the transition from the HS to LS phase.The presence of the surrounding molecules of the 2D superstructure facilitates the transition from the LS to HS state and the interaction between the molecular layer and the surface increases with the proportion of HS molecules,in line with the epitaxial growth of the monolayer and its similarities with the(011¯)plane of the HS bulk molecular crystal.The density of states resulting from the rPBE calculations is used to simulate STM images.An excellent agreement is found between the simulated STM images for the mixed state with 1/3 of HS molecules and the images acquired at a constant height for a submonolayer of this Fe(Ⅱ)complex on Au(111).
基金supported by the National Key R&D Program of China(2020YFA0406202)National Natural Science Foundation of China(22090042 and 21731001,11804021).
文摘In this work,the oxygen vacancy distributions in a 5 nm CeO_(2)nanocube were determined via Reverse Monte Carlo(RMC)simulations using neutron total scattering atomic pair distribution function(PDF)data,with further elaboration based on DFT calculations.The results showed that the oxygen vacancies tend to be located towards the surface of the CeO_(2)nanocube,and the distribution rate of oxygen vacancies suddenly drops in the subsurface region and inside the nanocube.There are two types of vacancies on the subsurface,O_(vac)^(sub1)with a surface O atom above it and O_(vac)^(sub2)without a surface O atom above it,and the respective proportions are 61.9%and 38.1%.According to the DFT calculations,the remaining two 4f electrons,present on account of oxygen vacancy formation,preferably localize at 1N positions with respect to Ovac sur and O_(vac)^(sub2)or at 2N positions with respect to O_(vac)^(sub1).Furthermore,it could be concluded that the two excess electrons in the case of CeO_(2)(100)tend to stay in surface or subsurface Ce layers,according to the high proportion of longer characteristic Ce^(3+)–O bond lengths obtained from the Reverse Monte Carlo(RMC)simulations.It should be noted that type-1 subsurface oxygen vacancies,O_(vac)^(sub1),are expected to be more probable to aggregate,revealing the characteristic existence of accumulated subsurface vacancies.
基金supported by the National Key Research and Development Program of China(Materials Genome Initiative No.2017YFB0701701)the National Natural Science Foundation of China(No.51872017 and 51872048)the Natural Science Foundation of Fujian Province(No.2016J01216 and 2017J01687).
文摘Black phosphorene has been proposed as a high-efficiency metal-free two-dimensional photocatalyst for hydrogen production by visible light-driven water splitting.In this work,based on the screening of materials by density functional theory calculations,the potentials of group Ⅳ and group Ⅵ isoelectronic co-doped black phosphorenes(BPs)as candidate photocatalysts were comprehensively evaluated.According to the essential criteria of stability,electronic structure features,as well as visible light photocatalytic hydrogen production performance,we identified Si–S,Si–Se,Ge–S and Ge–Se co-doped BPs as promising catalysts.We highlighted that the isoelectronic co-doping process is geometrically and thermodynamically favorable.Interestingly,the isoelectronic co-dopants did not affect the direct and clean band gap nature of pure BP,and they also enhanced the photocatalytic hydrogen production properties,retaining a strong anisotropic feature.We believe that our findings will shed light on the modulation and development of BP based metal-free two-dimensional photocatalysts.
文摘Fe-N-C catalysts represent the most promising class of platinum group metal-free(PGM-free)catalysts for the oxygen reduction reaction(ORR)in proton exchange membrane fuel cells(PEMFCs),exhibiting intrinsic activity potentially competitive with commercial Pt/C benchmarks.However,critical challenges persist[1].As revealed by theoretical calculations,the enhancement of intrinsic activity in Fe-N-C catalysts is constrained by inherent scaling relations among the adsorption free energies of ORR intermediates on the catalyst surface.
