表面修飾二維納米材料與電子結(jié)構(gòu)調(diào)制
發(fā)布時(shí)間：2018-11-12 09:18
【摘要】：二維無機(jī)納米材料,由于其超薄的結(jié)構(gòu)特征和量子限域效應(yīng),能夠表現(xiàn)出一個(gè)維度受限條件下新奇的電子與自旋結(jié)構(gòu),為廣泛應(yīng)用如新型的電子器件,磁性材料,高效的催化材料,以及能源存儲材料等帶來了新的材料平臺。隨著對二維無機(jī)納米材料研究的不斷深入,科學(xué)家們逐漸地由注重合成轉(zhuǎn)向探究和調(diào)控二維無機(jī)納米材料的本征物理性質(zhì)。相較于其三維塊體材料,二維超薄納米材料暴露出大量表面原子,使得其表面變得尤為重要。同時(shí),量子限域效應(yīng)使得二維納米材料的電子間有較強(qiáng)的相互作用,自旋、電荷、軌道、晶格間的耦合也更加強(qiáng)烈,這使得表面修飾二維納米材料能夠有效改變其局域電子的整體電荷和自旋態(tài),有望實(shí)現(xiàn)對其電子性質(zhì)、磁學(xué)性質(zhì)等本征屬性的有效調(diào)節(jié),為設(shè)計(jì)和開發(fā)新型無機(jī)二維納米材料帶來新思路。本論文以二維納米材料的電子結(jié)構(gòu)與其本征性質(zhì)為切入點(diǎn),以無機(jī)二維納米材料為研究對象,依據(jù)其超薄結(jié)構(gòu)的表面化學(xué)反應(yīng)性特點(diǎn),通過表面化學(xué)修飾策略對二維納米材料的電子結(jié)構(gòu)和自旋結(jié)構(gòu)進(jìn)行調(diào)制,以來實(shí)現(xiàn)本征物理性質(zhì)調(diào)控。我們設(shè)計(jì)和開展了包括表面化學(xué)吸附,表面氫修飾和表面硫修飾等有效表面修飾手段,對二維納米材料的本征物理性質(zhì)進(jìn)行了有效調(diào)制,構(gòu)建了新型二維納米材料結(jié)構(gòu),獲得了二維納米材料磁電輸運(yùn)行為調(diào)制,并應(yīng)用于電催化領(lǐng)域。本論文具體的內(nèi)容包括以下幾個(gè)方面:1、本工作中,我們通過表面修飾策略在二維二硒化鈮納米片表面吸附肼分子,實(shí)現(xiàn)了將本征鐵磁引入超導(dǎo)NbSe2二維結(jié)構(gòu)骨架中,從而獲得了超導(dǎo)與鐵磁共存于單一物相的二維納米材料。強(qiáng)極性和還原性的肼分子吸附在NbSe-2表面,既確保了 NbSe2的原始骨架結(jié)構(gòu)的完整性,又誘發(fā)了 NbSe2的局域結(jié)構(gòu)畸變,促使Nb-Se鍵的伸長,導(dǎo)致了 Nb-Se原子間共價(jià)作用力的削弱和增強(qiáng)了四價(jià)Nb離子的離子性,最終成功地向二二維超導(dǎo)NbSe-2材料中引入了鐵磁性。在單一的二維納米材料中實(shí)現(xiàn)的超導(dǎo)與鐵磁共存引發(fā)了耦合效應(yīng),如負(fù)磁阻效應(yīng)及近藤效應(yīng)。本工作提出了一種在二維材料中引入鐵磁性的有效策略。2、本工作中,我們通過有效的化學(xué)剝離方法獲得了表面氫修飾的二硫化鈦超薄納米片,表面修飾的氫原子向二硫化鈦平面導(dǎo)電骨架注入電子增加了載流子濃度,從而增強(qiáng)了 S-Ti-S骨架里的電子關(guān)聯(lián)作用并成功調(diào)控了二硫化鈦納米片的平面導(dǎo)電性。氫化二硫化鈦納米片的導(dǎo)電性隨著表面氫含量的增加而提升,由超薄表面氫修飾的二硫化鈦納米片組裝的薄膜的電導(dǎo)率在室溫下能夠達(dá)到6.76×104 S/m。與此同時(shí),表面氫修飾的二硫化鈦超薄納米片組裝的薄膜在機(jī)械性能和耐高壓性方面性能優(yōu)異。我們以PDMS(聚二甲基硅氧烷)為印章,可以將薄膜成功的轉(zhuǎn)移到任意基底上,而且保證薄膜的導(dǎo)電性在轉(zhuǎn)移過程中不會受到破壞。本研究表明通過這種表面修飾二維納米材料以加強(qiáng)強(qiáng)電子關(guān)聯(lián)體系,進(jìn)而來實(shí)現(xiàn)對二維納米材料電學(xué)性質(zhì)的調(diào)控是一種行之有效的手段。3、本工作中,通過表面硫修飾成功地調(diào)控了 Ni(OH)2納米片的電子結(jié)構(gòu),我們獲得了金屬態(tài)的二維過渡金屬氫氧化物。結(jié)合局域結(jié)構(gòu)表征和反應(yīng)熱力學(xué)計(jì)算,我們發(fā)現(xiàn)Ni(OH)2納米片的結(jié)構(gòu)骨架維持不變,其表面的部分氧原子被硫取代。表面硫修飾能夠?qū)崿F(xiàn)金屬態(tài)Ni(OH)2納米片的活性位點(diǎn)和電子態(tài)的雙重調(diào)制。金屬態(tài)Ni(OH)2納米片在室溫下展現(xiàn)出優(yōu)異的導(dǎo)電性(3.19× 103S/m)以保證有效的電子傳輸;納米片表面的金屬Ni離子周圍電子密度增加從而加速了 CO2從催化中心的脫附速率,進(jìn)而暴露出更多的催化位點(diǎn)。相對于原始的Ni(OH)2納米片,金屬態(tài)Ni(OH)2納米片的催化尿素氧化(UOR)過程中有更大的催化電流,更小的起始電位和更高的穩(wěn)定性。本工作提出了一種調(diào)控二維過渡金屬氫氧化物的電子. 結(jié)構(gòu)的有效方法。
[Abstract]:The two-dimensional inorganic nano-material can exhibit a novel electron and spin structure under the condition of limited dimension due to its ultra-thin structural characteristics and quantum confinement effect, and is a novel electronic device, a magnetic material and a high-efficiency catalytic material. and the energy storage material and the like. With the development of the study of two-dimensional inorganic nano-materials, the scientists gradually study and control the intrinsic physical properties of the two-dimensional inorganic nano-materials. Compared with the three-dimensional block material, the two-dimensional ultra-thin nano-material exposes a large number of surface atoms, so that the surface thereof becomes particularly important. meanwhile, the quantum-limited domain effect makes the electrons of the two-dimensional nano material have strong interaction, and the coupling between the spin, the charge, the track and the lattice is also stronger, so that the surface-modified two-dimensional nano-material can effectively change the whole charge and the spin state of the local electrons, It is expected to realize the effective regulation of its electronic properties, magnetic properties and other intrinsic properties, and to bring a new thought to the design and development of new inorganic two-dimensional nano-materials. Taking the electronic structure of two-dimensional nano-material and its intrinsic property as the starting point, the paper takes the inorganic two-dimensional nano-material as the research object, and according to the surface chemical reactivity of the ultra-thin structure, The surface chemical modification strategy is used to modulate the electronic structure and the spin structure of the two-dimensional nano-material. We designed and carried out effective surface modification methods including surface chemical adsorption, surface hydrogen modification and surface sulfur modification. The intrinsic physical properties of two-dimensional nano-materials were effectively modulated, and a new two-dimensional nano-material structure was constructed. and the two-dimensional nano material magnetoelectric transport behavior modulation is obtained, and the two-dimensional nano material magnetoelectric transport behavior modulation is applied to the field of electrocatalysis. The specific content of the thesis consists of the following aspects: 1. In the work, the molecule is adsorbed on the surface of the two-dimensional diselenide nano-sheet by a surface modification strategy, and the intrinsic ferromagnetic is introduced into the superconducting NbSe2 two-dimensional structure framework, so as to obtain the two-dimensional nano material of the superconducting and ferromagnetic co-existence in a single phase. the strong polarity and the reducing molecule are adsorbed on the surface of the NbSe-2, so that the integrity of the original framework structure of the NbSe2 is ensured, the local structural distortion of the NbSe2 is induced, the elongation of the Nb-Se bond is promoted, the covalent interaction between the Nb-Se atoms is weakened, and the ionic property of the tetravalent Nb ions is enhanced, and finally, the ferromagnetism is successfully introduced into the two-dimensional superconducting NbSe-2 material. The co-existence of superconductivity and ferromagnetic in a single two-dimensional nano-material induces a coupling effect, such as a negative magnetic resistance effect and a rattan effect. in this work, an effective strategy of ferromagnetism is introduced in two-dimensional material. the surface-modified hydrogen atom injected electrons into the two-sulfide-titanium planar conductive framework to increase the carrier concentration, thereby enhancing the electron correlation function in the S-Ti-S framework and successfully controlling the planar conductivity of the titanium disulfide nano-sheet. The conductivity of the hydrogenated titanium disulfide nanosheet increases with the increase of the surface hydrogen content, and the conductivity of the thin film assembled by the ultra-thin surface hydrogen modified titanium disulfide nano-sheet can reach 6.76-104S/ m at room temperature. At the same time, the film assembled with the surface hydrogen-modified titanium disulfide ultrathin nanosheet has excellent performance in terms of mechanical properties and high-pressure resistance. PDMS (polydimethylsiloxane) is used as a seal, so that the film can be successfully transferred to any substrate, and the conductivity of the film is ensured not to be damaged during the transfer process. in that work, the electronic structure of the Ni (OH) 2 nanosheet was successfully control by surface-sulfur modification, We have obtained a two-dimensional transition metal hydroxide in the form of a metal. The structural framework of the Ni (OH) 2 nanosheet was found to be unchanged in combination with the local structure characterization and the reaction thermodynamic calculation. The partial oxygen atoms of the surface of the Ni (OH) 2 nanosheets were replaced with sulfur. The surface-sulfur modification can realize the double modulation of the active site and the electronic state of the metal-state Ni (OH) 2 nanosheet. The metal-state Ni (OH) 2 nanosheet exhibits excellent electrical conductivity at room temperature (3.19-103S/ m) to ensure effective electron transport; the electron density around the metal Ni ions on the surface of the nanosheet increases so as to accelerate the desorption rate of CO2 from the catalytic center, thereby exposing more catalytic sites. With respect to the original Ni (OH) 2 nanosheet, the catalytic urea oxidation (UOR) of the metal-state Ni (OH) 2 nanosheet has a greater catalytic current, a smaller starting potential and higher stability. The invention provides an electron for regulating the two-dimensional transition metal hydroxide. the effective method of the structure.
【學(xué)位授予單位】：中國科學(xué)技術(shù)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：TB383.1
本文編號：2326697
[Abstract]:The two-dimensional inorganic nano-material can exhibit a novel electron and spin structure under the condition of limited dimension due to its ultra-thin structural characteristics and quantum confinement effect, and is a novel electronic device, a magnetic material and a high-efficiency catalytic material. and the energy storage material and the like. With the development of the study of two-dimensional inorganic nano-materials, the scientists gradually study and control the intrinsic physical properties of the two-dimensional inorganic nano-materials. Compared with the three-dimensional block material, the two-dimensional ultra-thin nano-material exposes a large number of surface atoms, so that the surface thereof becomes particularly important. meanwhile, the quantum-limited domain effect makes the electrons of the two-dimensional nano material have strong interaction, and the coupling between the spin, the charge, the track and the lattice is also stronger, so that the surface-modified two-dimensional nano-material can effectively change the whole charge and the spin state of the local electrons, It is expected to realize the effective regulation of its electronic properties, magnetic properties and other intrinsic properties, and to bring a new thought to the design and development of new inorganic two-dimensional nano-materials. Taking the electronic structure of two-dimensional nano-material and its intrinsic property as the starting point, the paper takes the inorganic two-dimensional nano-material as the research object, and according to the surface chemical reactivity of the ultra-thin structure, The surface chemical modification strategy is used to modulate the electronic structure and the spin structure of the two-dimensional nano-material. We designed and carried out effective surface modification methods including surface chemical adsorption, surface hydrogen modification and surface sulfur modification. The intrinsic physical properties of two-dimensional nano-materials were effectively modulated, and a new two-dimensional nano-material structure was constructed. and the two-dimensional nano material magnetoelectric transport behavior modulation is obtained, and the two-dimensional nano material magnetoelectric transport behavior modulation is applied to the field of electrocatalysis. The specific content of the thesis consists of the following aspects: 1. In the work, the molecule is adsorbed on the surface of the two-dimensional diselenide nano-sheet by a surface modification strategy, and the intrinsic ferromagnetic is introduced into the superconducting NbSe2 two-dimensional structure framework, so as to obtain the two-dimensional nano material of the superconducting and ferromagnetic co-existence in a single phase. the strong polarity and the reducing molecule are adsorbed on the surface of the NbSe-2, so that the integrity of the original framework structure of the NbSe2 is ensured, the local structural distortion of the NbSe2 is induced, the elongation of the Nb-Se bond is promoted, the covalent interaction between the Nb-Se atoms is weakened, and the ionic property of the tetravalent Nb ions is enhanced, and finally, the ferromagnetism is successfully introduced into the two-dimensional superconducting NbSe-2 material. The co-existence of superconductivity and ferromagnetic in a single two-dimensional nano-material induces a coupling effect, such as a negative magnetic resistance effect and a rattan effect. in this work, an effective strategy of ferromagnetism is introduced in two-dimensional material. the surface-modified hydrogen atom injected electrons into the two-sulfide-titanium planar conductive framework to increase the carrier concentration, thereby enhancing the electron correlation function in the S-Ti-S framework and successfully controlling the planar conductivity of the titanium disulfide nano-sheet. The conductivity of the hydrogenated titanium disulfide nanosheet increases with the increase of the surface hydrogen content, and the conductivity of the thin film assembled by the ultra-thin surface hydrogen modified titanium disulfide nano-sheet can reach 6.76-104S/ m at room temperature. At the same time, the film assembled with the surface hydrogen-modified titanium disulfide ultrathin nanosheet has excellent performance in terms of mechanical properties and high-pressure resistance. PDMS (polydimethylsiloxane) is used as a seal, so that the film can be successfully transferred to any substrate, and the conductivity of the film is ensured not to be damaged during the transfer process. in that work, the electronic structure of the Ni (OH) 2 nanosheet was successfully control by surface-sulfur modification, We have obtained a two-dimensional transition metal hydroxide in the form of a metal. The structural framework of the Ni (OH) 2 nanosheet was found to be unchanged in combination with the local structure characterization and the reaction thermodynamic calculation. The partial oxygen atoms of the surface of the Ni (OH) 2 nanosheets were replaced with sulfur. The surface-sulfur modification can realize the double modulation of the active site and the electronic state of the metal-state Ni (OH) 2 nanosheet. The metal-state Ni (OH) 2 nanosheet exhibits excellent electrical conductivity at room temperature (3.19-103S/ m) to ensure effective electron transport; the electron density around the metal Ni ions on the surface of the nanosheet increases so as to accelerate the desorption rate of CO2 from the catalytic center, thereby exposing more catalytic sites. With respect to the original Ni (OH) 2 nanosheet, the catalytic urea oxidation (UOR) of the metal-state Ni (OH) 2 nanosheet has a greater catalytic current, a smaller starting potential and higher stability. The invention provides an electron for regulating the two-dimensional transition metal hydroxide. the effective method of the structure.
【學(xué)位授予單位】：中國科學(xué)技術(shù)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：TB383.1
【參考文獻(xiàn)】
相關(guān)期刊論文 前1條
1 朱小姣;郭宇橋;吳長征;;表面化學(xué)修飾調(diào)控?zé)o機(jī)二維納米材料的磁性及其應(yīng)用[J];科學(xué)通報(bào);2017年20期
，本文編號：2326697
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