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过渡金属W、Mn、V、Ti掺杂二维材料MoSi_(2)N_(4)的第一性原理计算 被引量:1
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作者 姚登浪 黄泽琛 +2 位作者 郭祥 丁召 王一 《原子与分子物理学报》 北大核心 2024年第6期147-154,共8页
本文基于密度泛函理论(DFT)的第一性原理计算了W、Mn、V、Ti替位掺杂二维MoSi_(2)N_(4)后的几何结构、电子结构以及光学性质的变化.电子结构分析表明W、Mn、W、Ti替位掺杂二维MoSi_(2)N_(4)后的禁带宽度分别为1.806 e V、1.003 e V、1.2... 本文基于密度泛函理论(DFT)的第一性原理计算了W、Mn、V、Ti替位掺杂二维MoSi_(2)N_(4)后的几何结构、电子结构以及光学性质的变化.电子结构分析表明W、Mn、W、Ti替位掺杂二维MoSi_(2)N_(4)后的禁带宽度分别为1.806 e V、1.003 e V、1.218 e V和1.373 e V;四种过渡金属掺杂后MoSi_(2)N_(4)的带隙类型没有发生改变,均为间接带隙半导体;W掺杂后的杂质能级靠近价带顶,费米能级靠近价带顶,为p型半导体,杂质能级为受主能级;Mn掺杂后的杂质能级靠近导带底,费米能级靠近导带底,为n型半导体;V和Ti掺杂后杂质能级位于费米能级附近,为复合中心;光学性质分析表明,在2 e V~4 e V的能量区间内,W掺杂结构的吸收波长为336 nm,体系发生红移;Mn、V和Ti替位掺杂后的吸收波长分别为320 nm、358 nm和338 nm,且掺杂体系均发生蓝移. 展开更多
关键词 二维mosi_(2)n_(4) 第一性原理计算 掺杂 电子结构 光学性质
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Effects of vacancy and external electric field on the electronic properties of the MoSi_(2)N_(4)/graphene heterostructure 被引量:1
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作者 梁前 罗祥燕 +3 位作者 钱国林 王远帆 梁永超 谢泉 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期542-550,共9页
Recently,the newly synthesized septuple-atomic layer two-dimensional(2D)material MoSi_(2)N_(4)(MSN)has attracted attention worldwide.Our work delves into the effect of vacancies and external electric fields on the ele... Recently,the newly synthesized septuple-atomic layer two-dimensional(2D)material MoSi_(2)N_(4)(MSN)has attracted attention worldwide.Our work delves into the effect of vacancies and external electric fields on the electronic properties of the MSN/graphene(Gr)heterostructure using first-principles calculation.We find that four types of defective structures,N-in,N-out,Si and Mo vacancy defects of monolayer MSN and MSN/Gr heterostructure are stable in air.Moreover,vacancy defects can effectively modulate the charge transfer at the interface of the MSN/Gr heterostructure as well as the work function of the pristine monolayer MSN and MSN/Gr heterostructure.Finally,the application of an external electric field enables the dynamic switching between n-type and p-type Schottky contacts.Our work may offer the possibility of exceeding the capabilities of conventional Schottky diodes based on MSN/Gr heterostructures. 展开更多
关键词 mosi_(2)n_(4) vacancy defects external electric field Schottky contacts
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二维MoSi_(2)N_(4)/WSe_(2)异质结的第一性原理研究
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作者 梁前 谢泉 《原子与分子物理学报》 CAS 北大核心 2024年第2期87-92,共6页
实验上新合成的MoSi_(2)N_(4)(MSN)由于其独特的七原子层结构和电子特性引起了人们的广泛关注.本文搭建了一种由二维MSN与二维WSe_(2)(WS)垂直堆垛而成的二维MSN/WS异质结并基于第一性原理计算对其电子性质进行了计算,其表现出直接间隙... 实验上新合成的MoSi_(2)N_(4)(MSN)由于其独特的七原子层结构和电子特性引起了人们的广泛关注.本文搭建了一种由二维MSN与二维WSe_(2)(WS)垂直堆垛而成的二维MSN/WS异质结并基于第一性原理计算对其电子性质进行了计算,其表现出直接间隙半导体和I型能带排列的特性,具有1.46 eV的带隙.在异质结界面处存在一个由电荷耗尽层MSN指向电荷积累层WS微弱的内建电场.最后,通过施加双轴应变对二维MSN/WS异质结进行调控.发现在正双轴应变的作用下,MSN/WS异质结保持了原来直接带隙半导体和I型能带排列特性;在负双轴应变作用下,MSN/WS异质结由原来的直接带隙半导体转变为间接带隙半导体,当施加的负双轴应变达到-6%与-8%时,I型能带排列转变为Ⅱ型能带排列. 展开更多
关键词 mosi_(2)n_(4) WSe_(2) 双轴应变 能带排列
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双轴应变对NbSe_(2)/MoSi_(2)N_(4)肖特基势垒的调控
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作者 张宇哲 安梦雅 谢泉 《原子与分子物理学报》 CAS 北大核心 2025年第5期182-188,共7页
最近一种高质量的二维(Two-dimensional,2D)半导体材料MoSi_(2)N_(4)(MSN)在实验上被成功合成,具有优异的电气和机械性能.尽管最近有大量的研究致力于揭示MSN的材料特性,但到目前为止,对MSN的电接触物理特性的探索还比较少.在这项工作中... 最近一种高质量的二维(Two-dimensional,2D)半导体材料MoSi_(2)N_(4)(MSN)在实验上被成功合成,具有优异的电气和机械性能.尽管最近有大量的研究致力于揭示MSN的材料特性,但到目前为止,对MSN的电接触物理特性的探索还比较少.在这项工作中,构建了金属-半导体NbSe_(2)/MSN肖特基结并使用第一性原理密度泛函理论计算研究了该肖特基结的材料特性.发现NbSe_(2)/MSN接触具有超低肖特基势垒高度(Schottky barrier height,SBH),这有利于纳米电子学应用.SBH可以通过施加双轴应变的方式进行有效的调控.当施加拉伸应变时能实现NbSe_(2)/MSN肖特基结由p型肖特基接触转变为p型欧姆接触,而当施加较大的压缩应变时能实现p型肖特基接触和n型肖特基接触之间的转换.我们的研究结果为MSN的2D电触点的物理特性提供了见解,并将为设计基于MSN的2D纳米器件的高性能电触点提供关键的一步. 展开更多
关键词 mosi_(2)n_(4) nbSe_(2) 肖特基结 欧姆接触
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不同缺陷对二维MoSi_(2)N_(4)的电子结构及光学性质影响
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作者 王广 黄泽琛 +2 位作者 罗子江 郭祥 王一 《功能材料》 CAS CSCD 北大核心 2023年第7期7152-7157,共6页
二维材料以优良性能在各领域表现出巨大潜力,单层MoSi_(2)N_(4)材料具有非磁性半导体和良好的稳定性。采用基于密度泛函理论的第一性原理计算研究在氮、硅、钼空位下二维MoSi_(2)N_(4)的光电性质。研究结果显示:和本征二维MoSi_(2)N_(4... 二维材料以优良性能在各领域表现出巨大潜力,单层MoSi_(2)N_(4)材料具有非磁性半导体和良好的稳定性。采用基于密度泛函理论的第一性原理计算研究在氮、硅、钼空位下二维MoSi_(2)N_(4)的光电性质。研究结果显示:和本征二维MoSi_(2)N_(4)相比,外层氮和钼原子缺陷结构的禁带宽度缩减极大,而内层氮和硅原子缺陷结构的禁带宽度分别为0.781和0.736 eV,均有所减小。在导电类型方面,二维MoSi_(2)N_(4)因为内层氮缺陷由p型半导体转变为n型半导体。同时,各个缺陷结构均使二维MoSi_(2)N_(4)发生了不同程度的红移。二维MoSi_(2)N_(4)以材料性能优异,研究光电性能对新一代光电器件具有重要意义。 展开更多
关键词 二维mosi_(2)n_(4) 第一性原理计算 电子结构 光学性质
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Tuning transport coefficients of monolayer MoSi_(2)N_(4) with biaxial strain
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作者 Xiao-Shu Guo San-Dong Guo 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第6期484-489,共6页
Experimentally synthesized MoSi_(2)N_(4)(Science 369 670(2020)) is a piezoelectric semiconductor. Here, we systematically study the large biaxial(isotropic) strain effects(0.90–1.10) on electronic structures and tran... Experimentally synthesized MoSi_(2)N_(4)(Science 369 670(2020)) is a piezoelectric semiconductor. Here, we systematically study the large biaxial(isotropic) strain effects(0.90–1.10) on electronic structures and transport coefficients of monolayer MoSi_(2)N_(4) by density functional theory(DFT). With a/a0 from 0.90 to 1.10, the energy band gap firstly increases, and then decreases, which is due to transformation of conduction band minimum(CBM). Calculated results show that the MoSi_(2)N_(4) monolayer is mechanically stable in the considered strain range. It is found that the spin-orbital coupling(SOC) effects on Seebeck coefficient depend on the strain. In unstrained MoSi_(2)N_(4), the SOC has neglected influence on Seebeck coefficient. However, the SOC can produce important influence on Seebeck coefficient, when the strain is applied,for example, 0.96 strain. The compressive strain can change relative position and numbers of conduction band extrema(CBE), and then the strength of conduction bands convergence can be enhanced, to the benefit of n-type ZT_e. Only about0.96 strain can effectively improve n-type ZT_e. Our works imply that strain can effectively tune the electronic structures and transport coefficients of monolayer MoSi_(2)N_(4), and can motivate farther experimental exploration. 展开更多
关键词 mosi_(2)n_(4) electronic transport 2D materials
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Modulation of Schottky barrier in XSi_(2)N_(4)/graphene(X=Mo and W)heterojunctions by biaxial strain 被引量:1
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作者 Qian Liang Xiang-Yan Luo +2 位作者 Yi-Xin Wang Yong-Chao Liang Quan Xie 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第8期578-586,共9页
Reducing the Schottky barrier height(SBH)and even achieving the transition from Schottky contacts to Ohmic contacts are key challenges of achieving high energy efficiency and high-performance power devices.In this pap... Reducing the Schottky barrier height(SBH)and even achieving the transition from Schottky contacts to Ohmic contacts are key challenges of achieving high energy efficiency and high-performance power devices.In this paper,the modulation effects of biaxial strain on the electronic properties and Schottky barrier of Mo Si_(2)N_(4)(MSN)/graphene and WSi_(2)N_(4)(WSN)/graphene heterojunctions are examined by using first principles calculations.After the construction of heterojunctions,the electronic structures of MSN,WSN,and graphene are well preserved.Herein,we show that by applying suitable external strain to a heterojunction stacked by MSN or WSN—an emerging two-dimensional(2D)semiconductor family with excellent mechanical properties—and graphene,the heterojunction can be transformed from Schottky ptype contacts into n-type contacts,even highly efficient Ohmic contacts,making it of critical importance to unleash the tremendous potentials of graphene-based van der Waals(vd W)heterojunctions.Not only are these findings invaluable for designing high-performance graphene-based electronic devices,but also they provide an effective route to realizing dynamic switching either between n-type and p-type Schottky contacts,or between Schottky contacts and Ohmic contacts. 展开更多
关键词 mosi_(2)n_(4) Schottky barrier height HETEROJUnCTIOn biaxial strain
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Ultrathin origami accordion-like structure of vacancy-rich graphitized carbon nitride for enhancing CO_(2) photoreduction 被引量:1
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作者 Guangri Jia Zhongxu Wang +8 位作者 Ming Gong Ying Wang Lu Hua Li Yilong Dong Lulu Liu Lei Zhang Jingxiang Zhao Weitao Zheng Xiaoqiang Cui 《Carbon Energy》 SCIE CSCD 2023年第4期94-104,共11页
Retaining the ultrathin structure of two-dimensional materials is very important for stabilizing their catalytic performances.However,aggregation and restacking are unavoidable,to some extent,due to the van der Waals ... Retaining the ultrathin structure of two-dimensional materials is very important for stabilizing their catalytic performances.However,aggregation and restacking are unavoidable,to some extent,due to the van der Waals interlayer interaction of two-dimensional materials.Here,we address this challenge by preparing an origami accordion structure of ultrathin twodimensional graphitized carbon nitride(oa-C_(3)N_(4))with rich vacancies.This novel structured oa-C_(3)N_(4) shows exceptional photocatalytic activity for the CO_(2) reduction reaction,which is 8.1 times that of the pristine C_(3)N_(4).The unique structure not only prevents restacking but also increases light harvesting and the density of vacancy defects,which leads to modification of the electronic structure,regulation of the CO_(2) adsorption energy,and a decrease in the energy barrier of the carbon dioxide to carboxylic acid intermediate reaction.This study provides a new avenue for the development of stable highperformance two-dimensional catalytic materials. 展开更多
关键词 C_(3)n_(4) CO_(2)photoreduction molecular modification PHOTOCATALYSTS solar energy conversion two-dimensional materials
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Few-layered MoS_(2)anchored on 2D porous C_(3)N_(4)nanosheets for Ptfree photocatalytic hydrogen evolution 被引量:4
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作者 Nan Wang Dongxu Wang +7 位作者 Aiping Wu Siyu Wang Zhihui Li Chengxu Jin Youming Dong Fanyi Kong Chungui Tian Honggang Fu 《Nano Research》 SCIE EI CSCD 2023年第2期3524-3535,共12页
The Pt-free photocatalytic hydrogen evolution(PHE)has been the focus in the photocatalytic field.The catalytic system with the large accessible surface and good mass-transfer ability,as well as the intimate combinatio... The Pt-free photocatalytic hydrogen evolution(PHE)has been the focus in the photocatalytic field.The catalytic system with the large accessible surface and good mass-transfer ability,as well as the intimate combination of co-catalyst with semiconductor is promising for the promotion of the application.Here,we have reported the design of the two-dimensional(2D)porous C_(3)N_(4)nanosheets(PCN NS)intimately combined with few-layered MoS_(2)for the high-effective Pt-free PHE.The PCN NS were synthesized based on peeling the melamine–cyanuric acid precursor(MC precursor)by the triphenylphosphine(TP)molecular followed by the calcination,mainly due to the matched size of the(100)plane distance of the precursor(0.8 nm)and the height of TP molecular.The porous structure is favorable for the mass-transfer and the 2D structure having large accessible surface,both of which are positive to promote the photocatalytic ability.The few-layered MoS_(2)are grown on PCN to give 2D MoS_(2)/PCN composites based on anchoring phosphomolybdic acid(PMo_(12))cluster on polyetherimide(PEI)-modified PCN followed by the vulcanization.The few-layered MoS_(2)have abundant edge active sites,and its intimate combination with porous PCN NS is favorable for the faster transfer and separation of the electrons.The characterization together with the advantage of 2D porous structure can largely promote the photocatalytic ability.The MoS_(2)/PCN showed good PHE activity with the high hydrogen production activity of 4,270.8μmol·h^(−1)·g^(−1)under the simulated sunlight condition(AM1.5),which was 7.9 times of the corresponding MoS_(2)/bulk C_(3)N_(4)and 12.7 times of the 1 wt.%Pt/bulk C_(3)N_(4).The study is potentially meaningful for the synthesis of PCN-based catalytic systems. 展开更多
关键词 two-dimensional porous C_(3)n_(4)nanosheets photocatalysis few-layered MoS_(2) Pt-free hydrogen evolution
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Alkali-metal(Li, Na, and K)-adsorbed MoSi_(2)N_(4) monolayer: an investigation of its outstanding electronic, optical, and photocatalytic properties 被引量:1
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作者 Zhiyuan Sun Jing Xu +5 位作者 Nsajigwa Mwankemwa Wenxing Yang Xianwen Wu Zao Yi Shanjun Chen Weibin Zhang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2022年第1期96-104,共9页
Single-layer MoSi_(2)N_(4),a high-quality two-dimensional material,has recently been fabricated by chemical vapor deposition.Motivated by this latest experimental work,herein,we apply first principles calculations to ... Single-layer MoSi_(2)N_(4),a high-quality two-dimensional material,has recently been fabricated by chemical vapor deposition.Motivated by this latest experimental work,herein,we apply first principles calculations to investigate the electronic,optical,and photocatalytic properties of alkali-metal(Li,Na,and K)-adsorbed MoSi_(2)N_(4) monolayer.The electronic structure analysis shows that pristine MoSi_(2)N_(4) monolayer exhibits an indirect bandgap(E_(g)=1.89 eV).By contrast,the bandgaps of one Li-,Na-,and K-adsorbed MoSi_(2)N_(4) monolayer are 1.73 eV,1.61 eV,and 1.75 eV,respectively.Moreover,the work function of MoSi_(2)N_(4) monolayer(4.80 eV)is significantly reduced after the adsorption of alkali metal atoms.The work functions of one Li-,Na-,and K-adsorbed MoSi_(2)N_(4) monolayer are 1.50 eV,1.43 eV,and 2.03 eV,respectively.Then,optical investigations indicate that alkali metal adsorption processes substantially increase the visible light absorption range and coefficient of MoSi_(2)N_(4) monolayer.Furthermore,based on redox potential variations after alkali metals are adsorbed,Li-and Na-adsorbed MoSi_(2)N_(4) monolayers are more suitable for the water splitting photocatalytic process,and the Li-adsorbed case shows the highest potential application for CO_(2) reduction.In conclusion,alkali-metal-adsorbed MoSi_(2)N_(4) monolayer exhibits promising applications as novel optoelectronic devices and photocatalytic materials due to its unique physical and chemical properties. 展开更多
关键词 mosi_(2)n_(4) FIRST-PRInCIPLES alkali metal adsorbed electronic structure optical properties photocatalysis
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二维单层MoSi_(2)X_(4)(X=N,P,As)的电子结构及光学性质研究
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作者 龚雪 马新国 +3 位作者 万锋达 段汪洋 杨小玲 朱进容 《化学学报》 SCIE CAS CSCD 北大核心 2022年第4期510-516,共7页
采用平面波超软赝势方法研究了二维单层 MoSi_(2)X_(4) (X=N,P,As)的稳定性、电子结构和光学性质.研究结果显示,基于单层 MoSi_(2)N_(4)的两种同分异构体 M1 和 M2 所构建的六种晶体结构具有较好的动力学稳定性.通过能带和有效质量的计... 采用平面波超软赝势方法研究了二维单层 MoSi_(2)X_(4) (X=N,P,As)的稳定性、电子结构和光学性质.研究结果显示,基于单层 MoSi_(2)N_(4)的两种同分异构体 M1 和 M2 所构建的六种晶体结构具有较好的动力学稳定性.通过能带和有效质量的计算,单层MoSi_(2)N_(4)在 MoSi_(2)X_(4) (X=N,P,As)六种晶体结构中显示出最宽的间接带隙和最高的载流子迁移率.随后带边电位的计算结果表明,单层 MoSi_(2)N_(4)带边势分别为 M1:-0.368、1.416 V,M2:-0.227、1.837 V,其结果相较于MoSi_(2)P_(4)和 MoSi_(2)As_(4)导带边电位更负,价带边电位更正,是六种晶体结构中最适合用作光催化剂的材料.同时,光吸收谱的计算结果显示,单层 MoSi_(2)N_(4)的光学吸收表现出明显的各向异性,在可见光和紫外光波段内具有较强的光吸收能力,说明其在可见光催化领域有着潜在的应用前景.这些结果为进一步深入研究二维单层 MoSi_(2)N_(4)在光催化水解领域的应用提供了理论指导. 展开更多
关键词 mosi_(2)n_(4) 电子结构 光催化 第一性原理 光学性质
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Electrostatic self-assembly of 2D/2D CoWO_(4)/g-C_(3)N_(4)p-n heterojunction for improved photocatalytic hydrogen evolution:Built-in electric field modulated charge separation and mechanism unveiling 被引量:8
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作者 Haiyang Wang Ranran Niu +4 位作者 Jianhui Liu Sheng Guo Yongpeng Yang Zhongyi Liu Jun Li 《Nano Research》 SCIE EI CSCD 2022年第8期6987-6998,共12页
Two-dimensional(2D)semiconductor heterojunctions are considered as an effective strategy to achieve fast separation of photoinduced carriers.Herein,a novel CoWO_(4)/g-C_(3)N_(4)(CWO/CN)p–n junction was synthesized us... Two-dimensional(2D)semiconductor heterojunctions are considered as an effective strategy to achieve fast separation of photoinduced carriers.Herein,a novel CoWO_(4)/g-C_(3)N_(4)(CWO/CN)p–n junction was synthesized using an electrostatic selfassembly method.The constructed 2D/2D p–n heterostructure had a rich hetero-interface,increased charge density,and fast separation efficiency of photoinduced carriers.The in-situ Kelvin probe force microscopy confirmed that the separation pathway of photoinduced carriers through the interface obeyed an II-scheme charge transfer mechanism.Experimental results and density functional theory calculations indicated the differences of work function between CWO and CN induced the generation of built-in electric field,ensuring an efficient separation and transfer process of photoinduced carriers.Under the optimized conditions,the CWO/CN heterojunction displayed enhanced photocatalytic H_(2)generation activity under full spectrum and visible lights irradiation,respectively.Our study provides a novel approach to design 2D/2D hetero-structured photocatalysts based on p–n type semiconductor for photocatalytic H_(2)generation. 展开更多
关键词 p-n junction interfacial charge transfer two-dimensional/two-dimensional photocatalytic H_(2)generation CoWO_(4)/g-C_(3)n_(4)heterojunction
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Z-scheme systems of ASi_(2)N_4(A=Mo or W)for photocatalytic water splitting and nanogenerators 被引量:7
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作者 Jian Zeng Liang Xu +4 位作者 Xin Luo Tong Chen Shuai-Hao Tang Xin Huang Ling-Ling Wang 《Tungsten》 2022年第1期52-59,共8页
Z-scheme heterojunction catalysts have received great attention due to their efficient ability to separate electrons and holes.Here,using the first-principles calculations,we designed a series of promising two-dimensi... Z-scheme heterojunction catalysts have received great attention due to their efficient ability to separate electrons and holes.Here,using the first-principles calculations,we designed a series of promising two-dimensional(2D)/2D Z-scheme systems with interlayer inequivalent,including MoSi_(2)N_(4)/MoSi_(2)N_(4),WSi_(2)N_(4)/WSi_(2)N_(4) and MoSi_(2)N_(4)/WSi_(2)N_(4).Molecular dynamics simulation and phonon dispersion show that they have sufficient environmental stability.The inequivalent structure between the layers caused the directional formation of built-in potentials,driving the transfer of net charge between layers,which greatly enhanced their catalytic activity.The smaller band gap and enhanced light absorption performance further revealed their perfect catalytic performance.Moreover,all they met the redox potential requirements of water splitting in a range of pH 0-7,demonstrate they are very remarkable photocatalysts for H_(2)evolution.More interestingly,they also have good sliding ferroelectricity,and the opposite built-in potential can be obtained by sliding between layers,which is very promising for future nanogenerators.Our works may provide new insights into energy conversion devices. 展开更多
关键词 Tungsten mosi_(2)n_4 WSi_(2)n_4 Z-scheme systems Water splitting nAnOGEnERATORS First-principles calculations
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Monolayer MoSi_(2)_N(4-x) as promising electrocatalyst for hydrogen evolution reaction: A DFT prediction 被引量:2
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作者 Wangwang Qian Zhe Chen +1 位作者 Jinfeng Zhang Lichang Yin 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2022年第4期215-222,共8页
The density functional theory(DFT)calculations have been performed to investigate the catalytic properties of monolayer MoSi_(2)N_(4) for hydrogen evolution reaction(HER).The DFT results show that similar to the major... The density functional theory(DFT)calculations have been performed to investigate the catalytic properties of monolayer MoSi_(2)N_(4) for hydrogen evolution reaction(HER).The DFT results show that similar to the majority of other two-dimensional(2D)materials,the pristine MoSi_(2)N_(4) is inert for HER due to its weak affinity toward hydrogen,while monolayer MoSi_(2)N_(4-x)(x=0–0.25)exhibits the highly desirable HER catalytic activities by introducing surface nitrogen vacancy(NV).The predicted HER overpotential(0–60 mV)of monolayer MoSi_(2)N_(4-x) is lower than that(90 mV)of noble metal Pt,when the concentration of surface NV is lower than 5.6%.Electronic structure calculations show that the spin-polarized states appear around the Fermi level after introducing surface NV,thus making the surface NV on 2D MoSi_(2)N_(4) a quite suitable site for HER.Moreover,the HER activity of MoSi_(2)N_(4-x) is highly dependent on the surface NV concentration,which can be further related to the center of Si-3p band.Our results demonstrate that the newly discovered 2D MoSi_(2)N_(4) can be served as a promising electrocatalyst for HER via appropriate defect engineering. 展开更多
关键词 Hydrogen evolution reaction ELECTROCATALYST 2D material mosi_(2)n_(4) Surface nitrogen vacancy
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UV light driven high-performance room temperature surface acoustic wave NH_(3) gas sensor using sulfur-doped g-C_(3)N_(4) quantum dots
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作者 Kedhareswara Sairam Pasupuleti Sourabh S.Chougule +6 位作者 Devthade Vidyasagar Na-hyun Bak Namgee Jung Young-Heon Kim Jong-Hee Lee Song-Gang Kim Moon-Deock Kim 《Nano Research》 SCIE EI CSCD 2023年第5期7682-7695,共14页
Nanomaterials integrated surface acoustic wave(SAW)gas sensing technology has emerged as a promising candidate for realtime toxic gas sensing applications for environmental and human health safety.However,the developm... Nanomaterials integrated surface acoustic wave(SAW)gas sensing technology has emerged as a promising candidate for realtime toxic gas sensing applications for environmental and human health safety.However,the development of novel chemical interface based on two-dimensional(2D)sensing materials for SAW sensors for the rapid and sensitive detection of NH_(3)gas at room temperature(RT)still remains challenging.Herein,we report a highly selective RT NH_(3)gas sensor based on sulfur-doped graphitic carbon nitride quantum dots(S@g-C_(3)N_(4)QD)coated langasite(LGS)SAW sensor with enhanced sensitivity and recovery rate under ultraviolet(UV)illumination.Fascinatingly,the sensitivity of the S@g-C_(3)N_(4)QD/LGS SAW sensor to NH_(3)(500 ppb)at RT is dramatically enhanced by~4.5-fold with a low detection limit(~85 ppb),high selectivity,excellent reproducibility,fast response/recovery time(70 s/79 s)under UV activation(365 nm)as compared to dark condition.Additionally,the proposed sensor exhibited augmented NH_(3)detection capability across the broad range of relative humidity(20%–80%).Such remarkable gas sensing performances of the as-prepared sensor to NH_(3)are attributed to the high surface area,enhanced functional groups,sulfur defects,UV photogenerated charge carriers,facile charge transfer in the S@g-C_(3)N_(4)QD sensing layer,which further helps to improve the gas molecules adsorption that causes the increase in conductivity,resulting in larger frequency responses.The gas sensing mechanism of S@g-C_(3)N_(4)QD/LGS SAW sensor is ascribed to the enhanced electroacoustic effect,which is supported by the correlation of resistive type and COMSOL Multiphysics simulation studies.We envisage that the present work paves a promising strategy to develop the next generation 2D g-C_(3)N_(4)based high responsive RT SAW gas sensors. 展开更多
关键词 two-dimensional graphitic carbon nitride(2D g-C_(3)n_(4)) sulfur doping quantum dots surface acoustic wave(SAW)sensor nH_(3)gas electroacoustic effect
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