Li Xin

@article{ISI:001195156600001,
title = {Evolution of Graphene Dirac Fermions in Electric Double-Layer Transistors with a Soft Barrier},
author = {Fanrong Lin and Jiawei Liu and Huan Lu and Xin Liu and Ying Liu and Zhili Hu and Pin Lyu and Zhuhua Zhang and Jens Martin and Wanlin Guo and Yanpeng Liu},
doi = {10.1002/adfm.202400553},
times_cited = {0},
issn = {1616-301X},
year = {2024},
date = {2024-04-02},
journal = {ADVANCED FUNCTIONAL MATERIALS},
volume = {34},
number = {34},
publisher = {WILEY-V C H VERLAG GMBH},
address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY},
abstract = {The interface and dielectric environment of graphene transistors are of great importance to commercial circuit integrations. The tangling bond in oxide-based dielectric severely lagged the carrier mobility while the 2D dielectric layer (for instance, hexagonal boron nitride) unavoidably hastened complicated condensed physics even at room temperature. Herein, multilayer black phosphorus (BP) a versatile and widely-tunable dielectric candidate for manifesting graphene fermions is demonstrated. Because of hetero-interfacial charge redistributions, a vertical electric double-layer between the bottom BP layer and top graphene spontaneously forms with the central BP layer as a soft barrier. Under dual-gate modulation, abnormal step-like evolution of Dirac fermions and charge-transfer quantum Hall effect arises while the intrinsic Dirac behavior of graphene is preserved, ascribing to the gate-tunable charge redistributions of dielectric BP layer. Moreover, the electric double-layer transistors apply equally well to bilayer graphene with similar Dirac behavior but an enhanced interfacial charge interference. The findings not only create a new avenue to manipulate the fermions by assembling graphene with narrow-gapped 2D layered materials but also promote electric double-layer transistors as a new build block to design multifunctional devices.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{ISI:000554916100001,
title = {One-dimensional and two-dimensional synergized nanostructures for high-performing energy storage and conversion},
author = {Xin Li and John Wang},
doi = {10.1002/inf2.12040},
times_cited = {277},
year = {2020},
date = {2020-01-01},
journal = {INFOMAT},
volume = {2},
number = {1},
pages = {3-32},
publisher = {WILEY},
address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA},
abstract = {To address the worldwide energy challenges, advanced energy storage and conversion systems with high comprehensive performances, as the promising technologies, are inevitably required on a timely basis. The performance of these energy systems is intimately dependent on the properties of their electrodes. In addition to the electrode materials selection and their compositional optimization, materials fabrication with the designed nanostructure also provides significant benefits for their performances. In the past decade, considerable efforts have been made to promote the search for multidimensional nanostructures containing both one-dimensional (1D) and two-dimensional (2D) nanostructures in synergy, namely, 1D-2D synergized nanostructures. By developing the freestanding electrodes with such unique nanoarchitectures, the structural features and electroactivities of each component can be manifested, where the synergistic properties among them can be simultaneously obtained for further enhanced properties, such as the increased number of active sites, fast electronic/ionic transport, and so forth. This review overviews the state-of-the-art on the 1D-2D synergized nanostructures, which can be broadly divided into three groups, namely, core/shell, cactus-like, and sandwich-like nanostructures. For each category, we introduce them from the aspects of structural features, fabrication methodologies to their successful applications in different types of energy storage/conversion devices, including rechargeable batteries, supercapacitors, water splitting, and so forth. Finally, the main challenges faced by and perspectives on the 1D-2D synergized nanostructures are discussed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{ISI:000456199000016,
title = {(Ni,Co)Se_{2}/NiCo-LDH Core/Shell Structural Electrode with the Cactus-Like (Ni,Co)Se_{2} Core for Asymmetric Supercapacitors},
author = {Xin Li and Haijun Wu and Cao Guan and Abdelnaby M Elshahawy and Yangtao Dong and Stephen J Pennycook and John Wang},
doi = {10.1002/smll.201803895},
times_cited = {279},
issn = {1613-6810},
year = {2019},
date = {2019-01-18},
journal = {SMALL},
volume = {15},
number = {3},
publisher = {WILEY-V C H VERLAG GMBH},
address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY},
abstract = {Supercapacitors (SCs) have been widely studied as a class of promising energy-storage systems for powering next-generation E-vehicles and wearable electronics. Fabricating hybrid-types of electrode materials and designing smart nanoarchitectures are effective approaches to developing high-performance SCs. Herein, first, a Ni-Co selenide material (Ni,Co)Se-2 with special cactus-like structure as the core, to scaffold the NiCo-layered double hydroxides (LDHs) shell, is designed and fabricated. The cactus-like structural (Ni,Co)Se-2 core, as a highly conductive and robust support, promotes the electron transport as well as hinders the agglomeration of LDHs. The synergistic contributions from the two types of active materials together with the superior properties of the cactus-like nanostructure enable the (Ni,Co)Se-2/NiCo-LDH hybrid electrode to exhibit a high capacity of approximate to 170 mA h g(-1) (approximate to 1224 F g(-1)), good rate performance, and long durability. The as-assembled (Ni,Co)Se-2/NiCo-LDH//PC (porous carbon) asymmetric supercapacitor (ASC) with an operating voltage of 1.65 V delivers a high energy density of 39 W h kg(-1) at a power density of 1650 W kg(-1). Therefore, the cactus-like core/shell structure offers an effective pathway to engineer advanced electrodes. The assembled flexible ASC is demonstrated to effectively power electronic devices.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{ISI:000464491500035,
title = {NiFe Layered Double-Hydroxide Nanosheets on a Cactuslike (Ni,Co)Se_{2} Support for Water Oxidation},
author = {Xin Li and Haijun Wu and Yue Wu and Zongkui Kou and Stephen J Pennycook and John Wang},
doi = {10.1021/acsanm.8b01932},
times_cited = {11},
issn = {2574-0970},
year = {2019},
date = {2019-01-01},
journal = {ACS APPLIED NANO MATERIALS},
volume = {2},
number = {1},
pages = {325-333},
publisher = {AMER CHEMICAL SOC},
address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA},
abstract = {The oxygen evolution reaction (OER) is a pivotal half-reaction for next-generation energy storage and conversion technologies, for example, in metal-air batteries and water splitting. Herein, we report the preparation of a freestanding cactuslike structural (Ni,Co)Se-2 support shelled with NiFe layered double hydroxides (LDHs), as a highly active and durable OER catalyst with low cost. This cactuslike selenide support provides an interconnected conductive and robust framework, which can ensure efficient electron transfer and prevent the aggregation of LDHs. The synergistic combination and coupling effects of active NiFe-LDH and conductive (Ni,Co)Se, raise the intrinsic catalytic activity. As expected, when serving as an OER catalyst in 1 M KOH aqueous solution, the (Ni,Co)Se-2/NiFe-LDH presents a high activity with overpotential of approximate to 205 mV at a current density of 10 mV cm(-2), a small Tafel slope of approximate to 61 mV dec(-1), as well as a high durability observed at 30 h of a chronoamperometric test. The present study shows the promise of the cactuslike structural (Ni,Co)Se-2/NiFe-LDH as an effective OER catalyst, which provides a new thought for the fabrication of non-noble-metal catalysts and desired nanostructures.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{ISI:000431959500010,
title = {Cactus-Like NiCoP/NiCo-OH 3D Architecture with Tunable Composition for High-Performance Electrochemical Capacitors},
author = {Xin Li and Haijun Wu and Abdelnaby M Elshahawy and Ling Wang and Stephen J Pennycook and Cao Guan and John Wang},
doi = {10.1002/adfm.201800036},
times_cited = {376},
issn = {1616-301X},
year = {2018},
date = {2018-05-16},
journal = {ADVANCED FUNCTIONAL MATERIALS},
volume = {28},
number = {20},
publisher = {WILEY-V C H VERLAG GMBH},
address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY},
abstract = {To effectively enhance the energy density and overall performance of electrochemical capacitors (ECs), a new strategy is demonstrated to increase both the intrinsic activity of the reaction sites and their density. Herein, nickel cobalt phosphides (NiCoP) with high activity and nickel cobalt hydroxides (NiCo-OH) with good stability are purposely combined in a hierarchical cactus-like structure. The hierarchical electrode integrates the advantages of 1D nanospines for effective charge transport, 2D nanoflakes for mechanical stability, and 3D carbon cloth substrate for flexibility. The NiCoP/NiCo-OH 3D electrode delivers a high specific capacitance of approximate to 1100 F g(-1), which is around seven times higher than that of bare NiCo-OH. It also possesses approximate to 90% capacitance retention after 1000 charge-discharge cycles. An asymmetric supercapacitor composed of NiCoP/NiCo-OH cathode and metal-organic framework-derived porous carbon anode achieves a specific capacitance of approximate to 100 F g(-1), high energy density of approximate to 34 Wh kg(-1), and excellent cycling stability. The cactus-like NiCoP/NiCo-OH 3D electrode presents a great potential for ECs and is promising for other functional applications such as catalysts and batteries.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{ISI:000412925100006,
title = {Metal Phosphides and Phosphates-based Electrodes for Electrochemical Supercapacitors},
author = {Xin Li and Abdelnaby M Elshahawy and Cao Guan and John Wang},
doi = {10.1002/smll.201701530},
times_cited = {376},
issn = {1613-6810},
year = {2017},
date = {2017-10-18},
journal = {SMALL},
volume = {13},
number = {39},
publisher = {WILEY-V C H VERLAG GMBH},
address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY},
abstract = {Phosphorus compounds, such as metal phosphides and phosphates have shown excellent performances and great potential in electrochemical energy storage, which are demonstrated by research works published in recent years. Some of these metal phosphides and phosphates and their hybrids compare favorably with transition metal oxides/hydroxides, which have been studied extensively as a class of electrode materials for supercapacitor applications, where they have limitations in terms of electrical and ion conductivity and device stability. To be specific, metal phosphides have both metalloid characteristics and good electric conductivity. For metal phosphates, the open-framework structures with large channels and cavities endow them with good ion conductivity and charge storage capacity. In this review, we present the recent progress on metal phosphides and phosphates, by focusing on their advantages/disadvantages and potential applications as a new class of electrode materials in supercapacitors. The synthesis methods to prepare these metal phosphides/phosphates are looked into, together with the scientific insights involved, as they strongly affect the electrochemical energy storage performance. Particular attentions are paid to those hybrid-type materials, where strong synergistic effects exist. In the summary, the future perspectives and challenges for the metal phosphides, phosphates and hybrid-types are proposed and discussed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{ISI:000407540400038,
title = {Nanoflakes of Ni-Co LDH and Bi_{2}O_{3} Assembled in 3D Carbon Fiber Network for High-Performance Aqueous Rechargeable Ni/Bi Battery},
author = {Xin Li and Cao Guan and Yating Hu and John Wang},
doi = {10.1021/acsami.7b06696},
times_cited = {80},
issn = {1944-8244},
year = {2017},
date = {2017-08-09},
journal = {ACS APPLIED MATERIALS & INTERFACES},
volume = {9},
number = {31},
pages = {26008-26015},
publisher = {AMER CHEMICAL SOC},
address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA},
abstract = {For aqueous nickel/metal batteries, low energy density and poor rate properties are among the limiting factors for their applications, although they are the energy storage systems with high safety, high capacity, and low production cost. Here, we have developed a class of active materials consisting of porous nanoflakes of Ni-Co hydroxides and Bi2O3 that are successfully assembled on carbon substrates of carbon cloth/carbon nanofiber 3D network (CC/CNF). The combination of the porous Ni-Co hydroxides/Bi2O3 nano flakes with carbon substrate of 3D network is able to provide a large surface area, excellent conductivity, and promote synergistic effects, as a result of the interaction between the active materials and the carbon matrix. With the porous Ni-Co hydroxides and Bi2O3 nanoflakes, the Ni/Bi battery can deliver a high capacity of similar to 110 mA h g(-1) at a current density of 2 A g(-1). About 80% of its capacity (85 mA h g(-1)) can be retained when the current density increases to 20 A CI. The full cell can also maintain 93% of the initial capacity after 1000 charge/discharge cycles, showing great potential for Ni/Bi battery.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{ISI:000373456900011,
title = {Understanding the magnetic interaction between intrinsic defects and impurity ions in room-temperature ferromagnetic Mg_{1-\textit{x}}Fe\textit{_{x}}O thin films},
author = {Mukes Kapilashrami and Yung Jui Wang and Xin Li and Per-Anders Glans and Mei Fang and Anastasia V Riazanova and Lyubov M Belova and K V Rao and Yi Luo and Bernardo Barbiellini and Hsin Lin and Robert Markiewicz and Arun Bansil and Zahid Hussain and Jinghua Guo},
doi = {10.1088/0953-8984/28/15/156002},
times_cited = {7},
issn = {0953-8984},
year = {2016},
date = {2016-04-20},
journal = {JOURNAL OF PHYSICS-CONDENSED MATTER},
volume = {28},
number = {15},
publisher = {IOP PUBLISHING LTD},
address = {TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND},
abstract = {Understanding the nature and characteristics of the intrinsic defects and impurities in the dielectric barrier separating the ferromagnetic electrodes in a magnetic tunneling junction is of great importance for understanding the often observed 'barrier-breakdown' therein. In this connection, we present herein systematic experimental (SQUID and synchrotron-radiation-based x-ray absorption spectroscopy) and computational studies on the electronic and magnetic properties of Mg1-xFexO thin films. Our studies reveal: (i) defect aggregates comprised of basic and trimer units (Fe impurity coupled to 1 or 2 Mg vacancies) and (ii) existence of two competing magnetic orders, defect- and dopant-induced, with spin densities aligning anti-parallel if the trimer is present in the oxide matrix. These findings open up new avenues for designing tunneling barriers with high endurance and tunneling effect upon tuning the concentration/distribution of the two magnetic orders.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}