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Manipulating high-temperature superconductivity by oxygen doping in Bi2Sr2CaCu2O8+δ thin flakes

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National Science Review 2022年第10期9卷 112-119页

作者： Bin Lei Donghui Ma Shihao Liu Zeliang Sun Mengzhu Shi Weizhuang Zhuo Fanghang Yu Genda Gu Zhenyu Wang Xianhui Chen Key Laboratory of Strongly-Coupled Quantum Matter Physics Chinese Academy of Sciences and Department of Physics University of Science and Technology of China CAS Center for Excellence in Quantum Information and Quantum Physics Department of Condensed Matter Physics and Materials Science Brookhaven National Laboratory CAS Center for Excellence in Superconducting Electronics (CENSE) Collaborative Innovation Center of Advanced Microstructures Nanjing University

Harnessing the fascinating properties of correlated oxides requires precise control of their carrier density.Compared to other methods,oxygen doping provides an effective and more direct way to tune the electronic properties of correlated oxides.Although several approaches,such as thermal annealing and oxygen migration,have been introduced to change the oxygen content,a continuous and reversible solution that can be integrated with modern electronic technology is much in demand.Here,we report a novel ionic field-effect transistor using solid Gd-doped CeO2as the gate dielectric,which shows a remarkable carrier-density-tuning ability via electric-field-controlled oxygen concentration at room temperature.In Bi2Sr2CaCu2O8+δ(Bi-2212) thin flakes,we achieve a reversible superconductor-insulator transition by driving oxygen ions in and out of the samples with electric fields,and map out the phase diagram all the way from the insulating regime to the over-doped superconducting regime by continuously changing the oxygen doping level.Scaling analysis indicates that the reversible superconductor-insulator transition for the Bi-2212 thin flakes follows the theoretical description of a two-dimensional quantum phase transition.Our work provides a route for realizing electric-field control of phase transition in correlated oxides.Moreover,the configuration of this type of transistor makes heterostructure/interface engineering possible,thus having the potential to serve as the next-generation all-solid-state field-effect transistor.

关键词： high-temperature superconductivity oxygen doping electric field effect all-solid-state field effect transistor superconductor–insulator transition

UV light-induced oxygen doping in graphitic carbon nitride with suppressed deep trapping for enhancement in CO_(2) photoreduction activity

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Journal of Materials Science & Technology 2023年第2期133卷 135-144页

作者： Xiaolong Zhao Xiaoping Yi Wending Pan Yifei Wang Shijing Luo Yingguang Zhang Ruijie Xie Dennis Y.C.Leung Department of Mechanical Engineering the University of Hong KongPokfulam RoadHong KongChina School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083China School of Mechanical Engineering and Automation Harbin Institute of TechnologyShenzhen 518055China

While photoreduction of CO_(2) to CH 4 is an effective means of producing value-added fuels,common pho-tocatalysts have poor activity and low selectivity in photocatalytic CO_(2)-reduction processes.Even though creating defects is an effective photocatalyst fabrication route to improve photocatalytic activity,there are some challenges with the facile photocatalyst synthesis method.In this work,an O element is in-troduced into a graphitic carbon nitride(CN)skeleton through a precursory ultraviolet light irradiation pretreatment to increase the visible light absorption and enhance the carrier density of this modified non-metal CN photocatalyst;the charge transfer dynamics thereof are also studied through electrochem-ical tests,photoluminescence spectroscopy,and nanosecond transient absorption.We verify that the op-timized sample exhibits lower charge recombination and a suppressed 84 ns electron-trapping lifetime,compared to the 103 ns electron-trapping lifetime of the CN counterpart,and thereby contributes to ro-bust detrapping and a fast transfer of active electrons.Through density functional theory calculations,we find that the improved light absorption and increased electron density are ascribed to O-element doping,which enhances the CO_(2) adsorption energy and improves the CO_(2)-to-CH 4 photoreduction activity;it be-comes 17 times higher than that of the bare CN,and the selectivity is 3.8 times higher than that of CN.Moreover,the optimized sample demonstrates excellent cyclic stability in a 24-hour cycle test.

关键词： UV light oxygen doping Charge transfer Graphitic carbon nitride CO_(2)reduction

oxygen-doping of ZnIn_(2)S_(4) nanosheets towards boosted photocatalytic CO_(2) reduction

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Journal of Energy Chemistry 2021年第6期30卷 1-9,I0001页

作者： Bao Pan Yu Wu Baker Rhimi Jiani Qin Ying Huang Mingzhe Yuan Chuanyi Wang Key Laboratory of Chemical Additives for China National Light Industry College of Chemistry and Chemical EngineeringShaanxi University of Science and TechnologyXi’an 710021ShaanxiChina College of Environmental Science and Engineering Shaanxi University of Science and TechnologyXi’an 710021ShaanxiChina Shenyang Institute of Automation GuangzhouChinese Academy of ScienceGuangzhou 511400GuangdongChina Guangdong Engineering and Technology Research Center for Environmental Purification and Functional Materials Guangzhou 511400GuangdongChina

Engineering the electronic properties of semiconductor-based photocatalysts using elemental doping is an effective approach to improve their catalytic activity.Nevertheless,there still remain contradictions regarding the role of the dopants played in photocatalysis.Herein,ultrathin ZnIn_(2)S_(4)(ZIS) nanosheets with oxygen doping were synthesized by a one-pot solvothermal method.XRD,XPS and Raman spectral measurements support the presence of lattice oxygen in the oxygen-doped ZIS(O-ZIS) sample.With optimum doping of oxygen,the ultrathin O-ZIS nanosheets show enhanced CO_(2)-to-CO conversion activity with a CO_(2)-evolving rate of 1680 μmol h^(-1) g^(-1) under visible light irradiation,which is about 7 times higher than that of the pristine ZIS.First-principle calculations support that doping of oxygen in the lattice of ZnIn_(2)S_(4) nanosheets plays a key role in tuning its electronic properties.The remarkable photocatalytic performance of O-ZIS can be assigned to a synergistic consequence of a unique ultrathin-layered structure and an upward shift of the conduction band minimum(CBM) caused by the oxygen doping into ZIS and the quantum confinement effect(QCE) induced by the decreased particle size after doping as well as to the improved charge separation efficiency.The present work offers a simple elemental doping method to promote charge separation at atomic level and illustrates the roles played by oxygen doping in photocatalysis,giving new insights into highly efficient artificial photosynthesis.

关键词： ZnIn_(2)S_(4) Nanosheets oxygen doping Electronic properties Photocatalysis CO_(2)reduction

Significant control of metal-insulator transition temperature through catalytic excessive oxygen doping in high-performance vanadium dioxide nanobeam channel

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Journal of Materials Science & Technology 2020年第9期44卷 96-101页

作者： Minhwan Ko Sang Yeon Lee Jucheol Park Hyungtak Seo Department of Energy Systems Research Ajou UniversitySuwon16499Republic of Korea Gyeongbuk Science Technology Promotion Center Gumi Electronics&Information Technology Research InstituteGumi39717Republic of Korea Department of Materials Science and Engineering Ajou UniversitySuwon16499Republic of Korea

The strategy of a reliable transition temperature control of vanadium dioxide(VO2)is reported.Rectangular VO2 nanobeams were synthesized by a thermal chemical vapor deposition(TCVD)system.The metal-insulator transition(MIT)temperature increases to above 380K when the TiO2 ratio of the source is 5 at.%,although the Ti source is not physically doped into VO2 nanobeams.The XPS spectra of the V 2p orbital reveal the excessive oxidation of V after the TCVD processes with a higher TiO2 ratio,indicating that the TiO2 precursor is important in the O-doping of the surface V O bonds when forming volatile Ti-O gas species.Thus,TiO2 reactants can be used as a VO2 surface chemical modifier to manipulate the MIT transition temperature and maintain a homogenous VO2 phase,which is useful for a Mott device application with a record on/off switching ratio>104 and Mott transition temperature>380 K.

关键词： VO2 Mott transition Metal-insulator transition temperature oxygen doping Titanium catalyst

Enhanced CH4 selectivity in CO2 photocatalytic reduction over carbon quantum dots decorated and oxygen doping g-C3N4

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Nano Research 2019年第11期12卷 2749-2759页

作者： Qian Li Songcan Wang Zhuxing Sun Qijun Tang Yiqiu Liu Lianzhou Wang Haiqiang Wang Zhongbiao Wu Key Laboratory of Environment Remediation and Ecological Health Ministry of EducationCollege of Environmental and Resources ScienceZhejiang UniversityHangzhou 310058China Zhejiang Provincial Engineering Research Center of Industrial Boiler and Furnace Flue Gas Pollutin Control Hangzhou 311202China Nanomaterials Centre School of Chemical Engineering and Australian Institute for Bioengineering and NanotechnologyThe University of QueenslandBrisbaneQLD 4072Australia Schoo of Envionmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Graphitic carbon nitride(g-C3N4,CN)exhibits inefficient charge separation,deficient CO2 adsorption and activation sites,and sluggish surface reaction kinetics,which have been recognized as the main barriers to its application in CO2 photocatalytic reduction.In this work,carbon quantum dot(CQD)decoration and oxygen atom doping were applied to CN by a facile one-step hydrothermal method.The incorporated CQDs not only facilitate charge transfer and separation,but also provide alternative CO2 adsorption and activation sites.Further,the oxygen-atom-doped CN(OCN),in which oxygen doping is accompanied by the formation of nitrogen defects,proves to be a sustainable H^+ provider by facilitating the water dissociation and oxidation half-reactions.Because of the synergistic effect of the hybridized binary CQDs/OCN addressing the three challenging issues of the CN based materials,the performance of CO2 photocatalytic conversion to CH4 over CQDs/OCN-x(x represents the volume ratio of laboratory-used H2O2(30 wt.%)in the mixed solution)is dramatically improved by 11 times at least.The hybrid photocatalyst design and mechanism proposed in this work could inspire more rational design and fabrication of effective photocatalysts for CO2 photocatalytic conversion with a high CH4 selectivity.

关键词： photocalytic CO2 reduction graphitic carbon nitride(g-C3N4) carbon quantum dot oxygen doping

Influence of oxygen doping on resistive-switching characteristic of a-Si/c-Si device

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Journal of Semiconductors 2017年第12期38卷 22-25页

作者： Jiahua Zhang Da Chen Shihua Huang Physics Department Zhejiang Normal UniversityJinhua 321004China

The influence of oxygen doping on resistive-switching characteristics of Ag/a-Si/p^＋-c-Si device was investigated. By oxygen doping in the growth process of amorphous silicon, the device resistive-switching performances, such as the ON/OFF resistance ratios, yield and stability were improved, which may be ascribed to the significant reduction of defect density because of oxygen incorporation. The device I-V characteristics are strongly dependent on the oxygen doping concentration. As the oxygen doping concentration increases, the Si-rich device gradually transforms to an oxygen-rich device, and the device yield, switching characteristics, and stability may be improved for silver/oxygen-doped a-Si/p^＋-c-Si device. Finally, the device resistive-switching mechanism was ana- lyzed. Key words： amorphous silicon; resistive switching; oxygen doping

关键词： amorphous silicon resistive switching oxygen doping

Boosted on-chip energy storage with transistors

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National Science Review 2022年第10期9卷 56-57页

作者： Tongchao Liu Khalil Amine Chemical Sciences and Engineering Division Argonne National Laboratory Materials Science and Engineering Stanford University

On-chip energy-storage devices play an important role in powering wireless environmental sensors and microelectrome chanical systems [1,2].Starting from the 1980s,on-chip energy-storage devices,including microbatteries and super capacitors,have been applied to power the real-time clock on a chip [3].These tiny batteries/supercapacitors enable the real-time clock to keep working when the electronics are off.In this way,electronic devices can be restarted with a valid time.With the development of electronic devices,signal processing and communication have become much faster,while also requiring more powerful energy-storage devices to drive them [4-6].

关键词： high-temperature superconductivity oxygen doping electric field effect all-solid-state field effect transistor superconductor–insulator transition

Surface modulation of MoS_(2)/O-ZnIn_(2)S_(4) to boost photocatalytic H_(2)evolution

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Journal of Energy Chemistry 2022年第12期75卷 276-284,I0007页

作者： Yanhua Peng Xinlei Guo Shufei Xu Ya'nan Guo Dongsheng Zhang Meijiao Wang Guosong Wei Xiaolong Yang Zhuo Li Yan Zhang Fenghui Tian College of Chemistry and Chemical Engineering Qingdao UniversityQingdao 266071ShandongChina Comprehensive Technical Service Center of Penglai Customs Yantai 265600ShandongChina

To realize the continuous production of hydrogen energy,the efficient photocatalysts are required in the heterogeneous reaction for water splitting.Herein,we reported a surface modulation strategy,via doping oxygen atoms to tune the surface state of ZnIn_(2)S_(4)nanosheets with cocatalyst MoS_(2)modification,to enhance water adsorption and surface catalytic reaction for boosting the photocatalytic activity.Consequently,MoS_(2)/O-ZnIn_(2)S_(4)photocatalysts showed a remarkably superior photocatalytic H_(2)production performance of 4.002 mmol g^(-1)h^(-1)and an apparent quantum yield(AQY)of~2.53%,5.4 folds higher than ZnIn_(2)S_(4).Using operando infrared spectroscopy and DFT calculation,we revealed the dynamic structural evolution,as well as the active sites for water adsorption and the catalytic reaction at the MoS_(2)/O ZnIn_(2)S_(4)interface.This work reveals the effect of surface modulation on the photocatalytic activity for MoS_(2)/O-ZnIn_(2)S_(4)and offers a feasible method to devise excellent nanomaterial photocatalysts for H_(2)production.

关键词： Photocatalytic hydrogen evolution Surface modulation oxygen doping MoS_(2) Operando DRIFT DFT calculation

Engineering Dual oxygen Simultaneously Modified Boron Nitride for Boosting Adsorptive Desulfurization of Fuel

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Engineering 2022年第7期8卷 86-93页

作者： Jing Luo Yanchen Wei Yanhong Chao Chao Wang Hongping Li Jun Xiong Mingqing Hua Huaming Li Wenshuai Zhu School of Chemistry and Chemical Engineering&Institute for Energy Research Jiangsu UniversityZhenjiang 212013China State Key Laboratory of Heavy Oil Processing College of Chemical Engineering and EnvironmentChina University of Petroleum(Beijing)Beijing 102249China School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013China School of Pharmacy Jiangsu UniversityZhenjiang 212013China

oxygen atoms usually co-exist in the lattice of hexagonal boron nitride(h-BN). The understanding of interactions between the oxygen atoms and the adsorbate, however, is still ambiguous on improving adsorptive desulfurization performance. Herein, simultaneously oxygen atom-scale interior substitution and edge hydroxylation in BN structure were constructed via a polymer-based synthetic strategy.Experimental results indicated that the dual oxygen modified BN(BN–2O) exhibited an impressively increased adsorptive capacity about 12% higher than that of the edge hydroxylated BN(BN–OH) fabricated via a traditional method. The dibenzothiophene(DBT) was investigated to undergo multimolecular layer type coverage on the BN–2O uneven surface via π–π interaction, which was enhanced by the increased oxygen doping at the edges of BN–2O. The density functional theory calculations also unveiled that the oxygen atoms confined in BN interior structure could polarize the adsorbate, thereby resulting in a dipole interaction between the adsorbate and BN–2O. This effect endowed BN–2O with the ability to selectively adsorb DBT from the aromatic-rich fuel, thereafter leading to an impressive prospect for the adsorptive desulfurization performance of the fuel. The adsorptive result was in good accordance with Freundlich and pseudo-second-order adsorption kinetics model results. Therefore, the designing of a polymer-based strategy could be also extended to other heteroatom doping systems to enhance adsorptive performance.

关键词： Polymer-based synthetic strategy Interior substitution BN oxygen doping Adsorptive desulfurization