Hydrophobic treatment of the catalyst surfaces can suppress the competitive hydrogen evolution reaction(HER) during the nitrogen reduction reaction(NRR).In this work,the surface of Ti_(3)C_(2)Ti_(x) MXene is modified ...Hydrophobic treatment of the catalyst surfaces can suppress the competitive hydrogen evolution reaction(HER) during the nitrogen reduction reaction(NRR).In this work,the surface of Ti_(3)C_(2)Ti_(x) MXene is modified by cetyltrimethylammonium bromide(CTAB) and trimethoxy(3,3,4,4,5,5,6,6,7,7,8,8,8-trideca fluorooctyl) silane(FOTS) to increase the hydrophobicity of MXenes.The ammonia(NH_(3)) production rate and faradaic efficiency(FE) are improved from 37.62 to 54.01 μg h^(-1)mg_(cat)^(-1).and 5.5% to 18.1% at-0.7 V vs.RHE,respectively after surface modification.^(15)N isotopic labeling experiment confirms that nitrogen in produced ammonia originates from N_(2) in the electrolyte.The excellent NRR activity of surface hydrophobic MXenes is mainly due to surfactant molecules,which inhibit the entry of water molecules and the competitive HER,which have been verified by in situ FT-IR,DFT and molecular dynamics calculations.This strategy provides an ingenious method to design more active NRR electrocatalysts.展开更多
The presence of defects and detrimental reactions at NiO_(x)/perovskite interface extremely limit the efficiency performance and long-term stability of the perovskite solar cells(PSCs) based on NiO_(x).Herein,an amphi...The presence of defects and detrimental reactions at NiO_(x)/perovskite interface extremely limit the efficiency performance and long-term stability of the perovskite solar cells(PSCs) based on NiO_(x).Herein,an amphipathic molecule Triton X100(Triton) is modified on the NiO_(x)surface.The hydrophilic chain of Triton as a Lewis base additive can coordinate with the Ni3+on the NiO_(x)surface which can passivate the interfacial defects and hinder the detrimental reactions at the NiO_(x)/perovskite interface.Additionally,the hydrophobic chain of Triton protrudes from the NiO_(x)surface to prevent moisture from penetrating into the NiO_(x)/perovskite interface.Consequently,the NiO_(x)/Triton-based devices(MAPbI3as absorbing layer) show superior moisture and thermal stability,retaining 88.4% and 64.3% of the initial power conversion efficiency after storage in air(40%-50% relative humidity(RH)) at 25 ℃ for 1070 h and in N2at 85℃ for 800 h,respectively.Moreover,the efficiency increases from 17.59% to 19.89% because of the passivation defect and enhanced hole-extraction capability.Besides,the NiO_(x)/Triton-based PSCs with Cs_(0.05)(MA_(0.15)FA_(0.85))_(0.95)Pb(I_(0.85)Br_(0.15))3perovskite as the light-absorbing layer also exhibits better moisture and thermal stability compared to the control devices,indicating the viability of our strategies.Of particular note,a champion PCE of 22.35% and 20.46% was achieved for small-area(0.1 cm^(2)) and large-area(1.2 cm^(2)) NiO_(x)/Triton-based devices,respectively.展开更多
Nickel oxide (NiO_(x)) has significant cost and stability advantages over poly[bis (4-phenyl)(2,4,6-trimethyl phenyl)amine](PTAA) for inverted p-i-n perovskite solar cells (PSCs),but the poor NiO_(x)/perovskite contac...Nickel oxide (NiO_(x)) has significant cost and stability advantages over poly[bis (4-phenyl)(2,4,6-trimethyl phenyl)amine](PTAA) for inverted p-i-n perovskite solar cells (PSCs),but the poor NiO_(x)/perovskite contact stemming from some reactive species at the interface led to suboptimal device performance.To solve this problem,we take a multiple donor molecule approach,using 3,3’-(4,8-bis(hexylthio)benzo[1,2-b:4,5-b’]dithiophene-2,6-diyl)bis(10-(6-bromohexyl)-10H-phenoxazine)(BDT-POZ) as an example,to modify the NiO_(x)/perovskite interface.The primary goal was to reduce the under-coordinated Ni^(≥3+) cations via electron transfer from the donor molecules to NiO_(x),thus mitigating the detrimental reactions between perovskite and NiO_(x).Equally importantly,the hole extraction at the interface was greatly enhanced after the organic donor modification,since the hydrophobic species atop NiO_(x) not only enabled pinhole-free crystallization of the perovskite but also properly tuned the interfacial energy level alignment.Consequently,the PSCs with NiO_(x)/BDT-POZ HTL achieved a high power conversion efficiency (PCE) up to 20.16%,which compared excellently with that of the non-modified devices (17.83%).This work provides a new strategy to tackle the exacting issues that have so far impeded the development of NiO_(x) based PSCs.展开更多
Band alignment between NiO_(x) and nonpolar GaN plane and between NiO_(x) and semipolar GaN plane are measured by x-ray photoelectron spectroscopy. They demonstrate that the maximum value of the valence band in the un...Band alignment between NiO_(x) and nonpolar GaN plane and between NiO_(x) and semipolar GaN plane are measured by x-ray photoelectron spectroscopy. They demonstrate that the maximum value of the valence band in the unintentional-doped a-plane, m-plane, and r-plane GaN are comparable to each other, which means that all the substrates are of n-type with similar background carrier concentrations. However, the band offset at the NiO_(x)/GaN interface presents obvious crystalline plane dependency although they are coated with the same NiO_(x) films. By fitting the Ga 3 d spectrum obtained from the NiO_(x)/GaN interface, we find that relatively high Ga–O content at the interface corresponds to a small band offset. On the one hand, the high Ga–O content on the GaN surface will change the growth mode of NiO_(x). On the other hand, the affinity difference between Ga and O forms a dipole which will introduce an extra energy band bending.展开更多
In this paper,three-dimensional(3D)hollow Ti_(3)C_(2)T_(x)MXene tubes(HTCTs)with more–O terminal groups and fewer–F groups are successfully prepared via the template-oriented electrostatic self-assembly and the subs...In this paper,three-dimensional(3D)hollow Ti_(3)C_(2)T_(x)MXene tubes(HTCTs)with more–O terminal groups and fewer–F groups are successfully prepared via the template-oriented electrostatic self-assembly and the subsequent annealing treatment.The obtained 3D hollow structure with large specific surface area,unique porous structure,and enlarged interlayer spacing could prevent the re-stacking of twodimensional(2D)sheets and shorten the diffusion pathway of ions.Furthermore,density functional theory(DFT)calculations and electrochemical tests reveal that Ti_(3)C_(2)O_(2)MXene possesses higher adsorption ability and lower diffusion barrier for K^(+)and Li^(+)compared to Ti_(3)C_(2)MXene dominated by–F terminal groups.Benefiting from the synergistic effect of the structural design and surface modification,the asprepared 3D HTCTs exhibit excellent electrochemical performance as anodes for K^(+)and Li^(+)storage compared with 2D Ti_(3)C_(2)T_(x)sheets(TCSs).展开更多
The paper is dedicated to the consideration of the chemical mesoscopics notions application for the explanation of polymeric materials modification mechanism by the metal carbon mesoscopic composites.The main peculiar...The paper is dedicated to the consideration of the chemical mesoscopics notions application for the explanation of polymeric materials modification mechanism by the metal carbon mesoscopic composites.The main peculiarities of these nanosized particles are following:a)the presence of unpaired electrons on the carbon cover;b)the structure of carbon cover consists from poly acetylene and carbine fragments;c)the atomic magnetic moment of inner metal is equaled to more than 1,3μB.The metal carbon mesocomposites activity depends on the medium and conditions influence because of the possible changes of the phase coherency and quantization of negative charges.展开更多
基金fundings from the National Natural Science Foundation of China (No. 51872173)Taishan Scholar Foundation of Shandong Province (No. tsqn201812068)+3 种基金Natural Science Foundation of Shandong Province (No. ZR2022JQ21)Higher School Youth Innovation Team of Shandong Province (No. 2019KJA013)Hong Kong Scholars Program (No. XJ2019042)Innovation and Technology Commission of the Hong Kong Special Administrative Region (No. ITC-CNERC14EG03)。
文摘Hydrophobic treatment of the catalyst surfaces can suppress the competitive hydrogen evolution reaction(HER) during the nitrogen reduction reaction(NRR).In this work,the surface of Ti_(3)C_(2)Ti_(x) MXene is modified by cetyltrimethylammonium bromide(CTAB) and trimethoxy(3,3,4,4,5,5,6,6,7,7,8,8,8-trideca fluorooctyl) silane(FOTS) to increase the hydrophobicity of MXenes.The ammonia(NH_(3)) production rate and faradaic efficiency(FE) are improved from 37.62 to 54.01 μg h^(-1)mg_(cat)^(-1).and 5.5% to 18.1% at-0.7 V vs.RHE,respectively after surface modification.^(15)N isotopic labeling experiment confirms that nitrogen in produced ammonia originates from N_(2) in the electrolyte.The excellent NRR activity of surface hydrophobic MXenes is mainly due to surfactant molecules,which inhibit the entry of water molecules and the competitive HER,which have been verified by in situ FT-IR,DFT and molecular dynamics calculations.This strategy provides an ingenious method to design more active NRR electrocatalysts.
基金supported by the National Key Research and Development Program of China(2018YFA0208701)the National Natural Science Foundation of China(21773308)+7 种基金the Research Funds of Renmin University of China(2017030013,201903020 and 20XNH059)the Fundamental Research Funds for Central Universities(China)supported by the Solar Energy Research Institute of Singapore(SERIS) at the National University of Singapore(NUS)supported by NUSthe National Research Foundation Singapore(NRF)the Energy Market Authority of Singapore(EMA)the Singapore Economic Development Board(EDB)the financial support from the China Scholarship Council(CSC) funding。
文摘The presence of defects and detrimental reactions at NiO_(x)/perovskite interface extremely limit the efficiency performance and long-term stability of the perovskite solar cells(PSCs) based on NiO_(x).Herein,an amphipathic molecule Triton X100(Triton) is modified on the NiO_(x)surface.The hydrophilic chain of Triton as a Lewis base additive can coordinate with the Ni3+on the NiO_(x)surface which can passivate the interfacial defects and hinder the detrimental reactions at the NiO_(x)/perovskite interface.Additionally,the hydrophobic chain of Triton protrudes from the NiO_(x)surface to prevent moisture from penetrating into the NiO_(x)/perovskite interface.Consequently,the NiO_(x)/Triton-based devices(MAPbI3as absorbing layer) show superior moisture and thermal stability,retaining 88.4% and 64.3% of the initial power conversion efficiency after storage in air(40%-50% relative humidity(RH)) at 25 ℃ for 1070 h and in N2at 85℃ for 800 h,respectively.Moreover,the efficiency increases from 17.59% to 19.89% because of the passivation defect and enhanced hole-extraction capability.Besides,the NiO_(x)/Triton-based PSCs with Cs_(0.05)(MA_(0.15)FA_(0.85))_(0.95)Pb(I_(0.85)Br_(0.15))3perovskite as the light-absorbing layer also exhibits better moisture and thermal stability compared to the control devices,indicating the viability of our strategies.Of particular note,a champion PCE of 22.35% and 20.46% was achieved for small-area(0.1 cm^(2)) and large-area(1.2 cm^(2)) NiO_(x)/Triton-based devices,respectively.
基金the support from NSFC(U2001217,21972006,51803035)the Shenzhen Peacock Plan(KQTD2016053015544057)+4 种基金the Shenzhen-Hong Kong Innovation Circle United Research Project(SGLH20180622092406130)the Nanshan Pilot Plan(LHTD20170001)the Guangdong Basic and Applied Basic Research Foundation(2020A1515110981)the Research Fund Program of Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices(2019B121203003)the Shenzhen Fundamental Research Program(JCYJ20190813105205501)。
文摘Nickel oxide (NiO_(x)) has significant cost and stability advantages over poly[bis (4-phenyl)(2,4,6-trimethyl phenyl)amine](PTAA) for inverted p-i-n perovskite solar cells (PSCs),but the poor NiO_(x)/perovskite contact stemming from some reactive species at the interface led to suboptimal device performance.To solve this problem,we take a multiple donor molecule approach,using 3,3’-(4,8-bis(hexylthio)benzo[1,2-b:4,5-b’]dithiophene-2,6-diyl)bis(10-(6-bromohexyl)-10H-phenoxazine)(BDT-POZ) as an example,to modify the NiO_(x)/perovskite interface.The primary goal was to reduce the under-coordinated Ni^(≥3+) cations via electron transfer from the donor molecules to NiO_(x),thus mitigating the detrimental reactions between perovskite and NiO_(x).Equally importantly,the hole extraction at the interface was greatly enhanced after the organic donor modification,since the hydrophobic species atop NiO_(x) not only enabled pinhole-free crystallization of the perovskite but also properly tuned the interfacial energy level alignment.Consequently,the PSCs with NiO_(x)/BDT-POZ HTL achieved a high power conversion efficiency (PCE) up to 20.16%,which compared excellently with that of the non-modified devices (17.83%).This work provides a new strategy to tackle the exacting issues that have so far impeded the development of NiO_(x) based PSCs.
基金supported by the Fund from the Open Project Key Laboratory of Microelectronic Devices and Integrated Technology,China (Grant No. 202006)the Doctoral Research Support Foundation of Shenyang Ligong University,China (Grant No. 1010147000914)the Science and Technology Program of Ningbo,China (Grant No. 2019B10129)。
文摘Band alignment between NiO_(x) and nonpolar GaN plane and between NiO_(x) and semipolar GaN plane are measured by x-ray photoelectron spectroscopy. They demonstrate that the maximum value of the valence band in the unintentional-doped a-plane, m-plane, and r-plane GaN are comparable to each other, which means that all the substrates are of n-type with similar background carrier concentrations. However, the band offset at the NiO_(x)/GaN interface presents obvious crystalline plane dependency although they are coated with the same NiO_(x) films. By fitting the Ga 3 d spectrum obtained from the NiO_(x)/GaN interface, we find that relatively high Ga–O content at the interface corresponds to a small band offset. On the one hand, the high Ga–O content on the GaN surface will change the growth mode of NiO_(x). On the other hand, the affinity difference between Ga and O forms a dipole which will introduce an extra energy band bending.
基金supported by the National Natural Science Foundation of China(52104309,52072274)the Natural Science Foundation of Hubei Province(2021CFB011)the Program of Hubei Province,China(T201602 and 2017CFA004)。
文摘In this paper,three-dimensional(3D)hollow Ti_(3)C_(2)T_(x)MXene tubes(HTCTs)with more–O terminal groups and fewer–F groups are successfully prepared via the template-oriented electrostatic self-assembly and the subsequent annealing treatment.The obtained 3D hollow structure with large specific surface area,unique porous structure,and enlarged interlayer spacing could prevent the re-stacking of twodimensional(2D)sheets and shorten the diffusion pathway of ions.Furthermore,density functional theory(DFT)calculations and electrochemical tests reveal that Ti_(3)C_(2)O_(2)MXene possesses higher adsorption ability and lower diffusion barrier for K^(+)and Li^(+)compared to Ti_(3)C_(2)MXene dominated by–F terminal groups.Benefiting from the synergistic effect of the structural design and surface modification,the asprepared 3D HTCTs exhibit excellent electrochemical performance as anodes for K^(+)and Li^(+)storage compared with 2D Ti_(3)C_(2)T_(x)sheets(TCSs).
文摘The paper is dedicated to the consideration of the chemical mesoscopics notions application for the explanation of polymeric materials modification mechanism by the metal carbon mesoscopic composites.The main peculiarities of these nanosized particles are following:a)the presence of unpaired electrons on the carbon cover;b)the structure of carbon cover consists from poly acetylene and carbine fragments;c)the atomic magnetic moment of inner metal is equaled to more than 1,3μB.The metal carbon mesocomposites activity depends on the medium and conditions influence because of the possible changes of the phase coherency and quantization of negative charges.
