【作者】 孙诚；

【导师】 顾佳俊；

【作者基本信息】 上海交通大学 ， 材料科学与工程， 2019， 硕士

【摘要】 面对全球性的能源危机和环境污染问题,清洁、低成本、高效的太阳能转换和利用具有十分重要的意义。其中,利用光催化将太阳能转换为可存储和运输的氢能,利用光热效应进行海水淡化可同时解决能源短缺、环境污染以及淡水资源紧缺问题。如何提高光能转换材料的能量转换效率是当今太阳能转换领域普遍存在的瓶颈问题。优良的材料构型设计与研究对于提高光能转换材料的性能具有重要的影响作用。而自然生物体的独特结构优势启发我们向大自然取经,其中,动物模板中蝴蝶以其多样的种类、大小、形态、色彩、结构等为具有生物精细构型的遗态材料的研究与制备提供了丰富的天然模板。闪蝶属则多具有精细树枝状叠层肋结构,具有表面等离子体共振的增益作用,在半导体光催化水分解体系中具有重要的借鉴意义。本文采用生物模板制备法(遗态法),以天然蝴蝶翅膀结构为模板,通过对其物理结构和形态的复制以及改变化学成分,获得自热生物三维结构和人为赋予特性的金属微纳材料。以光催化水分解与光热水蒸发为例,主要结果如下:(1)在“遗态法”获得金属银蝶翅的基础上,进一步采用溶胶凝胶法,合成与蝶翅的“嵴”尺寸相匹配的半导体纳米颗粒。通过物理沉积的方法,使得纳米颗粒与前述所制备的金属蝶翅相复合,制得催化所需的三维微纳结构光催化剂。(2)通过光催化降解甲基橙和光催化全分解水的两个体系,对三维银-氯化银催化剂的光催化性能进行表征,并且将破坏结构的银-氯化银体系作为对比实验,得到二者在同一体系下有显著差异,表明具有三维结构的SPR银-氯化银对光催化产生促进作用。(3)基于多物理场有限元计算等理论方法,结合材料制备与光热水蒸发研究,成功制得具有微纳叠层肋构型的银蝶翅基板,光热转换效率达到76.58%(与无蝶翅空白样品比较提高5倍).(4)利用所得的光热金属蝶翅材料作为光吸收膜,设计高效率光热蒸水的验证装置,适用于海水淡化。进而探索利用光刻等微纳加工方法进行人工仿生制备的途径及可行性,为高效、大面积制备新一代光热转换材料提供新思路。成功制得直径30cm,有效受光面积900cm~2的金属蝶翅光热器件,光热转换效率为64.34%(与无蝶翅空白样品比较提高5倍)。综上所述,本文研究了以蝶翅为模板的微纳金属结构在光能转换领域的实际应用,分别实现了高效光催化全分解水以及高效光热水蒸发的器件设计,对设计、制备具有分级微纳构型的光能转换材料具有启发和借鉴意义。更多还原

【Abstract】 In the face of global energy crisis and environmental pollution,clean,low-cost and efficient solar energy conversion and utilization are of great significance.Among them,applications of photocatalysis to convert solar energy into transportable hydrogen energy and of photothermal effect for seawater desalination can simultaneously solve energy shortage,environmental pollution and shortage of fresh water resources.How to improve the energy conversion efficiency of light energy conversion materials is a common bottleneck problem in the field of solar energy conversion.Excellent material design and research have an important influence on improving the performance of light energy conversion materials.The unique structural advantages of natural organisms inspire us to learn from nature.Among them,butterflies provide biologically fine structures for the research with their diverse species,size,shape,color and structure.Specially,the Morpho menelaus has a fine dendritic laminated rib structure with surface plasmon resonance enhancing,which has important reference significance in semiconductor photocatalytic water splitting.In this paper,the biological template preparation method(Morphology Method)is adopted,and the natural butterfly wing is used as a template to obtain the three-dimensional structure,and the chemical composition is changed to obtain its physical morphology and artificially imparted properties.Main results include:(1)On the basis of obtaining the silver butterfly wings of the"Morphology method",the sol-gel method was further used to synthesize semiconductor nanoparticles matching the rib size of the butterfly fins.The three-dimensional micro/nanostructure photocatalyst required for the catalysis is prepared by physically depositing the nanoparticle with the metal wing prepared as described above.(2)The photocatalytic properties were characterized by two systems,including photocatalytic degradation of methyl orange and water splitting.The Ag-AgCl system with crushed wing was used as a comparative experiment.There is a significant difference under the same system,indicating that the three-dimensional structure of plasmonic Ag-AgCl promotes photocatalysis.(3)Based on the theoretical method of multi-physics finite element calculation,combined with material preparation and photothermal water evaporation,the silver wing substrate with micro-nano laminated rib configuration was successfully fabricated,and the photothermal conversion efficiency reached 76.58%.(5 times higher than blank sample without butterfly wings)(4)The obtained photothermal metal wing is used as a light absorbing film,and a high-efficiency photothermal evaporation device is designed,which is for seawater desalination.Furthermore,the ways and feasibility of artificial biomimetic preparation by micro-nano processing methods such as photolithography are explored,which provides a new idea for efficient and large-area preparation of new generation photothermal conversion materials.In this case,a metal wing-based photothermal device with a diameter of 30cm was successfully prepared,with an effective light receiving area of 900cm~2,and the photothermal conversion efficiency was 64.34%.(5 times higher than blank sample without butterfly wings)In conclusion,photocatalytic water splitting and photothermal water evaporation are taken as examples to study the practical application of micro-nano metal structures with butterfly wings as templates in the field of light energy conversion,which have inspiration and reference for designing and preparing light energy conversion materials with hierarchical configuration.更多还原