BCN纳米片的制备、复合及性能研究
发布时间：2018-11-15 11:18
【摘要】：新型无机非金属材料硼碳氮(BCN)纳米片,由于具有可调节的带隙宽度和良好的稳定性等优点,近年来引起人们的广泛关注。本论文针对BCN纳米片的制备和性能进行了系统研究。提出了金属钠(Na)插层剥离、置换法和煅烧法等几种利用固相反应制备BCN纳米片的方法,并研究了 BCN纳米片在稀磁半导体、非线性光学、超级电容器和光催化等领域的应用,分析了 BCN纳米片结构对性能的影响。具体研究内容如下:(1)Na插层剥离制备BCN纳米片及其铁磁性性能研究以金属Na插层剥离的氮化硼纳米片(BNNSs)和石墨烯为原料,将两者随机交叠在一起,然后高温煅烧处理将石墨烯中的C原子引入BNNSs晶格中,形成BCN纳米片。采用这种方法可以高效地制备BCN材料,并通过控制石墨烯的添加量可以实现不同C含量的BCN材料的制备。得到的BCN纳米片厚度大约3 nm,具有完整的晶格结构。BCN纳米片中的C原子附近的电子态呈现自旋极化的现象,导致BCN纳米片具有磁性。相比于抗磁性的石墨烯和BNNSs,BCN纳米片表现出明显的铁磁性,居里温度可达到463 K,是一种常温铁磁性半导体材料。另外BCN纳米片在磁场中可以实现定向排列,为下一步BCN材料的实际应用提供了实验基础。(2)置换法制备BCN纳米片及其非线性光学性能研究采用Na剥离方法能高效制备BCN纳米片,但是实验过程较复杂,我们采用球磨的方法代替Na剥离过程,研究了置换法制备BCN纳米片的新方法。置换法制备的BCN纳米片具有良好的晶格结构和极薄的片层厚度(3 nm)。BCN纳米片表现出非常强的非线性吸收性能。BCN纳米片在较低能量密度下,表现出显著的可饱和吸收特性,而在高能量密度下表现出反饱和吸收的特性。通过控制纳米片中C含量的大小可以实现对BCN纳米片的非线性性能调控。研究结果表明BCN纳米片可以作为一种新型的非线性光学材料,具有很大的应用前景。(3)固相合成制备BCN纳米片及其超电性能研究采用Na剥离和置换法得到BCN纳米片中C含量整体较少。为了进一步提高BCN纳米片中的碳含量,我们提出直接煅烧C源、B源和N源的固相合成方法制备BCN纳米片。研究结果发现利用这种方法可以制备得到C含量高达60 at%以上的多孔BCN纳米片。多孔BCN纳米片的厚度大约在1.7 nm左右,具有较好的晶格结构。多孔BCN纳米片具有良好的导电性能和较大的比表面积。因此这种多孔BCN纳米片可以利用其优秀的电学性能应用在超级电容器领域。实验结果发现,BCN纳米片作为工作电极,具有良好的电容性能。在0.1A/g的电流密度下BCN纳米片的容量为407 F/g,说明BCN纳米片作为工作电极具有非常高的容量。研究结果表明BCN纳米片作为一种新型的超电材料,具有很大的应用前景。(4)BCN纳米片、0D/2D CdS/BCN和0D/2D CdS/MoS2复合材料的光催化性能研究C原子的引入能够明显的降低BCN材料的带隙,通过XPS、莫特-肖特基曲线和紫外-可见吸收漫反射测试,不仅发现随着C含量的增加BCN纳米片的带隙逐渐降低,还发现BCN纳米片的能级结构与水的带隙相匹配。通过BCN纳米片的光催化降解染料和光催化产氢性能测试,发现BCN纳米片可以作为一种新型光催化材料应用于能源与环境领域。以0.5 wt%的Pt做助催化剂,BCN纳米片在全光下产氢效率可以达到400 μmol h-1g-1。BCN纳米片除了自身具有一定的光催化产氢性质以外,它还可以与其它传统光催化剂进行复合,提高其光产氢性能。以0D/2D CdS/BCN纳米复合物为研究对象,发现该复合物的光产氢效率可以达到2.39 mmol h-1 g-1,远高于单纯的CdS和BCN纳米片的光产氢效率。但是发现,虽然CdS纳米颗粒可以分布在BCN纳米片表面,但是两者之间的电子传导存在一定的阻碍,这不利于光催化产氢性能的提高。为了克服这个障碍,设计采用二维过渡金属硫化物代替BCN纳米片作为基底,制备了 0D/2D CdS/MoS2纳米复合物,其光产氢效率可以达到35.6 mmol h-1 g-1,而且该复合物结构可以有效抑制CdS催化剂的硫腐蚀,具有非常高的光产氢循环稳定性。
[Abstract]:The new inorganic non-metallic material boron-carbon-nitrogen (BCN) nanosheet has attracted wide attention in recent years due to the advantages of adjustable band gap width and good stability. The preparation and properties of the BCN nano-sheet are systematically studied. The method of preparing BCN nanosheet by solid phase reaction, such as metal sodium (Na) insertion layer stripping, displacement method, and sintering method, is put forward, and the application of the BCN nano-sheet in the fields of dilute magnetic semiconductor, non-linear optics, super capacitor and photocatalysis is also studied. The effect of the structure of the BCN on the performance is analyzed. The specific research contents are as follows: (1) the preparation of the BCN nano-sheet and the ferromagnetic properties of the Na plug-in layer are carried out, and the boron nitride nano-sheets (BNSPs) and the graphene which are separated by the metal Na-inserting layer are used as raw materials, and the two are randomly overlapped together, and then the C atoms in the graphene are introduced into the BNNS crystal lattice by the high-temperature sintering treatment to form the BCN nano-sheet. The BCN material can be prepared with high efficiency by adopting the method, and the preparation of the BCN material with different C content can be realized by controlling the addition amount of the graphene. The resulting BCN nanosheet has a thickness of about 3 nm and has a complete lattice structure. The electron state near the C atom in the BCN nanosheet exhibits spin-polarization, resulting in a magnetic property of the BCN nanosheet. Compared with the anti-magnetic graphene and the BNNS, the BCN nano-sheet shows obvious ferromagnetic property, and the Curie temperature can reach 463K, and is a normal-temperature ferromagnetic semiconductor material. in addition, that BCN nano-sheet can realize the directional arrangement in the magnetic field, and provides an experimental basis for the practical application of the next BCN material. (2) The preparation of the BCN nanosheet and its non-linear optical properties by the displacement method can be used to prepare the BCN nano-sheet with high efficiency, but the experimental process is more complicated. We use the method of ball-milling instead of the Na-stripping process, and the new method for preparing the BCN nano-sheet by the displacement method is studied. The BCN nanosheet prepared by the displacement method has a good lattice structure and a very thin layer thickness (3 nm). the bcn nanosheets exhibit very strong non-linear absorption properties. The BCN nanosheets exhibit significant saturable absorption properties at lower energy densities and exhibit anti-saturation absorption at high energy density. The control of the nonlinear properties of the BCN nanosheet can be achieved by controlling the size of the C content in the nanosheet. The results show that the BCN nanosheet can be used as a new nonlinear optical material and has a great application prospect. (3) The preparation of the BCN nano-sheet and its super-electrical property by solid-phase synthesis, the content of C content in the BCN nano-sheet is less than that of the BCN nano-sheet by the method of Na-stripping and displacement. In order to further improve the carbon content in the BCN nano-sheet, the solid-phase synthesis method of the direct-fired C-source, the B-source and the N-source was proposed to prepare the BCN nanosheet. The results show that a porous BCN nanosheet with a C content of up to 60 at% can be prepared by this method. The thickness of the porous BCN nanosheet is about 1. 7 nm, and has a good lattice structure. The porous BCN nanosheet has a good electrical conductivity and a larger specific surface area. Therefore, the porous BCN nano-sheet can be applied to the field of the super capacitor by using the excellent electrical performance. The experimental results show that the BCN nanosheet is used as a working electrode and has good capacitance performance. The capacity of the BCN nanosheet was 407 F/ g at a current density of 0. 1A/ g, indicating that the BCN nanosheet had a very high capacity as the working electrode. The results show that the BCN nanosheet is a new type of super-electric material and has a great application prospect. (4) The photocatalytic performance of the BCN nano-sheet, the 0D/ 2D CdS/ BCN and the 0D/ 2D CdS/ MoS2 composite material can obviously reduce the band gap of the BCN material, and through the XPS, the Mott-Schottky curve and the ultraviolet-visible absorption diffuse reflection test, It is not only found that the band gap of the BCN nanosheet decreases with the increase of C content, but also that the energy level structure of the BCN nano-sheet is matched with the band gap of water. It is found that the BCN nanosheet can be used as a new type of photo-catalytic material in the field of energy and environment. in addition to its own photocatalytic hydrogen-producing property, the BCN nanosheet can be compounded with other conventional photocatalysts to improve its light-producing performance. The light-producing efficiency of the composite was 2.39 mmol/ h-1 g-1, which was much higher than that of the pure CdS and BCN nanoparticles. However, it has been found that, although CdS nanoparticles can be distributed on the surface of the BCN nanosheet, there is a certain barrier between the electron conduction between the two, which is not conducive to the improvement of the photocatalytic hydrogen production performance. In order to overcome this obstacle, a 2D/ 2D CdS/ MoS2 nano-composite was prepared by using a two-dimensional transition metal sulfide instead of the BCN nano-sheet as a substrate. The light-producing efficiency of the composite was 35. 6 mmol/ h-1 g-1, and the composite structure can effectively inhibit the sulfur corrosion of the CdS catalyst. with very high light-producing cycle stability.
【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O613.81;TB383.1
本文编号：2333166
[Abstract]:The new inorganic non-metallic material boron-carbon-nitrogen (BCN) nanosheet has attracted wide attention in recent years due to the advantages of adjustable band gap width and good stability. The preparation and properties of the BCN nano-sheet are systematically studied. The method of preparing BCN nanosheet by solid phase reaction, such as metal sodium (Na) insertion layer stripping, displacement method, and sintering method, is put forward, and the application of the BCN nano-sheet in the fields of dilute magnetic semiconductor, non-linear optics, super capacitor and photocatalysis is also studied. The effect of the structure of the BCN on the performance is analyzed. The specific research contents are as follows: (1) the preparation of the BCN nano-sheet and the ferromagnetic properties of the Na plug-in layer are carried out, and the boron nitride nano-sheets (BNSPs) and the graphene which are separated by the metal Na-inserting layer are used as raw materials, and the two are randomly overlapped together, and then the C atoms in the graphene are introduced into the BNNS crystal lattice by the high-temperature sintering treatment to form the BCN nano-sheet. The BCN material can be prepared with high efficiency by adopting the method, and the preparation of the BCN material with different C content can be realized by controlling the addition amount of the graphene. The resulting BCN nanosheet has a thickness of about 3 nm and has a complete lattice structure. The electron state near the C atom in the BCN nanosheet exhibits spin-polarization, resulting in a magnetic property of the BCN nanosheet. Compared with the anti-magnetic graphene and the BNNS, the BCN nano-sheet shows obvious ferromagnetic property, and the Curie temperature can reach 463K, and is a normal-temperature ferromagnetic semiconductor material. in addition, that BCN nano-sheet can realize the directional arrangement in the magnetic field, and provides an experimental basis for the practical application of the next BCN material. (2) The preparation of the BCN nanosheet and its non-linear optical properties by the displacement method can be used to prepare the BCN nano-sheet with high efficiency, but the experimental process is more complicated. We use the method of ball-milling instead of the Na-stripping process, and the new method for preparing the BCN nano-sheet by the displacement method is studied. The BCN nanosheet prepared by the displacement method has a good lattice structure and a very thin layer thickness (3 nm). the bcn nanosheets exhibit very strong non-linear absorption properties. The BCN nanosheets exhibit significant saturable absorption properties at lower energy densities and exhibit anti-saturation absorption at high energy density. The control of the nonlinear properties of the BCN nanosheet can be achieved by controlling the size of the C content in the nanosheet. The results show that the BCN nanosheet can be used as a new nonlinear optical material and has a great application prospect. (3) The preparation of the BCN nano-sheet and its super-electrical property by solid-phase synthesis, the content of C content in the BCN nano-sheet is less than that of the BCN nano-sheet by the method of Na-stripping and displacement. In order to further improve the carbon content in the BCN nano-sheet, the solid-phase synthesis method of the direct-fired C-source, the B-source and the N-source was proposed to prepare the BCN nanosheet. The results show that a porous BCN nanosheet with a C content of up to 60 at% can be prepared by this method. The thickness of the porous BCN nanosheet is about 1. 7 nm, and has a good lattice structure. The porous BCN nanosheet has a good electrical conductivity and a larger specific surface area. Therefore, the porous BCN nano-sheet can be applied to the field of the super capacitor by using the excellent electrical performance. The experimental results show that the BCN nanosheet is used as a working electrode and has good capacitance performance. The capacity of the BCN nanosheet was 407 F/ g at a current density of 0. 1A/ g, indicating that the BCN nanosheet had a very high capacity as the working electrode. The results show that the BCN nanosheet is a new type of super-electric material and has a great application prospect. (4) The photocatalytic performance of the BCN nano-sheet, the 0D/ 2D CdS/ BCN and the 0D/ 2D CdS/ MoS2 composite material can obviously reduce the band gap of the BCN material, and through the XPS, the Mott-Schottky curve and the ultraviolet-visible absorption diffuse reflection test, It is not only found that the band gap of the BCN nanosheet decreases with the increase of C content, but also that the energy level structure of the BCN nano-sheet is matched with the band gap of water. It is found that the BCN nanosheet can be used as a new type of photo-catalytic material in the field of energy and environment. in addition to its own photocatalytic hydrogen-producing property, the BCN nanosheet can be compounded with other conventional photocatalysts to improve its light-producing performance. The light-producing efficiency of the composite was 2.39 mmol/ h-1 g-1, which was much higher than that of the pure CdS and BCN nanoparticles. However, it has been found that, although CdS nanoparticles can be distributed on the surface of the BCN nanosheet, there is a certain barrier between the electron conduction between the two, which is not conducive to the improvement of the photocatalytic hydrogen production performance. In order to overcome this obstacle, a 2D/ 2D CdS/ MoS2 nano-composite was prepared by using a two-dimensional transition metal sulfide instead of the BCN nano-sheet as a substrate. The light-producing efficiency of the composite was 35. 6 mmol/ h-1 g-1, and the composite structure can effectively inhibit the sulfur corrosion of the CdS catalyst. with very high light-producing cycle stability.
【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O613.81;TB383.1
【参考文献】
相关期刊论文 前1条
1 张明文;罗志珊;周敏;黄彩进;王心晨;;层状Co/h-BCN纳米复合材料光催化分解水产氧研究（英文）[J];Science China Materials;2015年11期
，本文编号：2333166
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