介晶半导体材料的合成及应用研究进展  

Advances in Synthesis and Application of Mesocrystals Semiconductor

作　　者：孙健武[1] 葛美英[2] 尹桂林[1,2] 张芳[2] 何丹农[1,2] SUN Jianwu;GE Meiying;YIN Guilin;ZHANG Fang;HE Dannong(School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240;National Engineering Research Center for Nanotechnology,Shanghai 200241)

机构地区：[1]上海交通大学材料科学与工程学院,上海200240 [2]纳米技术及应用国家工程研究中心,上海200241

出　　处：《材料导报》2019年第7期1119-1124,共6页Materials Reports

基　　金：上海青年科技启明星计划项目(16QB1402400);国家自然科学基金(21677095)~~

摘　　要：传统半导体纳米材料大部分为多晶结构或单晶结构。而介晶是一类由初级纳米颗粒以结晶学有序的方式自组装而成的纳米粒子超结构,具有类似单晶的原子结构和散射特征,既保留着初级纳米颗粒的晶界,又表现出强烈的各向异性,从而具有与多晶和单晶均不同的独特结构与性能。例如,介晶结构中的初级纳米颗粒以一定的方式相互连接,与无序堆积的多晶相比,具有极高的结晶性,甚至接近单晶,能够有效减小载流子在材料内部的复合概率;初级纳米颗粒之间的晶界并未完全消失,存在一定的空隙,具有较高的空隙率和比表面积以提供更多的活性位点;初级纳米颗粒在定向吸附过程中有序地取向排列,暴露出高能晶面,显著提高了其反应活性。金属氧化物半导体材料在光催化、电化学和气敏等领域应用广泛,其反应机理均是发生在材料表面的气-液、气-气、气-固反应,因而均需要材料具有大的比表面积和较高的表面活性。而介晶结构是以纳米颗粒作为基本构筑单元的非经典结晶产物,具有比表面积大、孔隙率高、表面活性高等优点,有望获得远超过传统材料的优异性能,因此近年来介晶结构金属氧化物半导体的制备成为了研究热点。研究者们基于物理或者化学驱动的纳米架构自组装过程,通过改进传统制备工艺,如水热法、溶剂热法、离子热法等,成功调控纳米材料成核、生长的方式,制备出具有介晶结构的TiO_2、ZnO、CuO、SnO_2等半导体材料,并且通过优化制备工艺,可以调节材料的比表面积、孔隙率和表面活性。进一步分析介晶结构与性能的构效关系,对推广介晶结构材料的应用具有重大的指导意义。但是目前介晶的研究还处于起步阶段,各种组分、形貌和结构的介晶的合成、结晶理论的基础研究以及材料的应用开发都还有待进一步探索。本文归纳了介晶半导体As is known to all,conventional semiconductor nanomaterials are mostly polycrystals or single crystals.While,mesocrystals belong to a kind of superstructures self-assembled from primary nanoparticles in a crystalline order,showing identical atomic structures and scattering patterns to single crystals.The grain boundaries of primary nanoparticles retained in mesocrystal as well as its intense anisotropism,resulting in distinct structures and properties different from those of ordinary polycrystals and single crystals.For instance,primary nanoparticles in mesocrystal connect with each other in a certain way,therefore,compared with disordered polycrystals,mesocrystal exhibits much higher crystallinity even close to single crystal,which effectively reduces recombination probability of carriers in the material.The grain boundary between the primary nanoparticles is not completely disappeared,and the retained grain boundaries bring high porosity and specific surface which provides more active sites.The primary nanoparticles are arranged in order during oriented attachment,and high energy facets are exposed,leading to the great enhancement in activity.Metal oxide semiconductors possess widespread application in photocatalysis,electrochemistry and gas sensor.Reactions in different applications all take place on the material surfaces like gas-liquid,gas-gas,gas-solid,where large specific surface area and high surface activity are required.Mesocrystals with nanoparticles as basic building blocks are expected to obtain superior properties to conventional mateirals,therefore preparation of mesocrystalline metal oxide semiconductors has become the research focus.Based on nano self-assembly process driven by physical or chemical forces,researchers have successfully regulated the nucleation and growth of nanomaterials,and synthesized semiconductor mesocrystals like TiO2,ZnO,CuO and SnO2 by improving traditional preparation technology,including hydrothermal,solvothermal,ion-thermal methods.Besides,specific surface area,porosity

关 键 词：介晶结构 非经典结晶 三维超结构 半导体材料 高能晶面 

分 类 号：TB34[一般工业技术—材料科学与工程]