荧光碳纳米颗粒基复合体界面的设计及其对光致电子转移效率的影响

The fluorescent efficiency and tunability of carbon nanoparticles (CNPs) are determined by the sp2- and sp3-hybridized mixture, size and surface state. The size-induced quantum confinement makes the nanostructures from mixed hybridization, which generally takes place on the surface, become luminescent centers. Thus whether the radiative recombination of excitons can be realized or not depends on the surface states of CNPs. When other element atoms combine with the superficial carbon atoms, their interface could exhibit special electron/bandgap structures, leading to reduce nonradiative recombination of excitons or photoinduced electron transfers. To improve the utilization rate of light, the composites of fluorescent CNPs and the other nanostructure including of metal and its oxide and sulfide will be fabricated. Importantly, the interface structure, size and morphology will be regulated to discover the relationship between the interfaces of CNP-matrix composites and photoinduced electron transfers with the help of theoretical models. On the other hand, CNP-matrix composites will be grafted on through-hole structures of the alginates for recycling and then preventing secondary pollution. .Many results have been obtained under the support of present NSFC. More than thirteen papers have been published on the famous journals, such as J. Chem. Mater., Carbon, and Appl. Phys. Lett., and two state invention patents have been applied. Moreover, Dr. Hu was awarded the title of the Top Young Academic Leaders of Higher Learning Institutions of Shanxi.

碳纳米颗粒荧光发射能否高效可调决定于sp2和sp3的混合杂化、尺寸和表面态。尺寸诱导的量子限域效应促使了混合杂化结构成为了发光中心，而该发光结构更容易形成在表面，因此光致激发电子能否发生辐射复合及其效率受制于碳纳米颗粒的表面态。基于其它元素原子与碳纳米颗粒表面结合，形成的界面会表现出独特的电子/带隙结构，可降低非辐射复合的发生或者导致激发电子（能量）的转移。为了提高光能的利用率，本项目拟把荧光碳纳米颗粒与金属及其氧化物、硫化物复合并对其界面结构、尺寸和形态调控；再把所得荧光碳纳米颗粒基复合体嫁接海藻酸盐通孔结构上，实现回收以避免二次污染；通过测试表征和理论分析明确出荧光碳纳米颗粒基复合体界面与光致电子转移效率的关系。已在J. Chem. Mater.、Carbon、 Appl. Phys. Lett.等期刊发表学术论文13篇，申请发明专利2项，授予山西省高等学校青年学术带头称号。

本项目属于青年-面上连续资助项目，是在青年项目研究基础之上拓展的研究。荧光碳纳米颗粒以元素无毒、合成简单且具有较优异的光学性能和广泛的应用前景而备受关注。青年项目从尺寸、结构、成分等影响材料性能的基本因素出发，发展了控制合成方法并阐明了影响荧光碳纳米颗粒发光高效可调的因素。以明确出的表面态是光生电荷控制的关键为切入点，本项目开展了利用表界面调制光生电荷行为的研究，以期提高荧光碳纳米颗粒及其复合体对光能的利用率。首先针对荧光碳纳米颗粒表面成分进行了设计，实现了多种异质元素功能修饰的荧光碳纳米颗粒的制备，并给出了这些异质元素对荧光碳纳米颗粒的光吸收及转化的影响规律。发展了金属、金属化合物与荧光碳纳米颗粒复合的技术，解析了金属、金属化合物在调制荧光碳纳米颗粒光吸收及转化的机制，获得了具有高光转换效率的复合体。发展出了荧光碳纳米颗粒自组装技术；成功的把荧光碳纳米颗粒及其复合体嫁接在了多孔载体上（如海藻酸盐凝胶、多孔泡沫金属），不仅提高了光的吸收及转化，还实现了纳米材料的回收再利用。该项目取得成果为设计荧光碳纳米颗粒及其广泛应用奠定了理论和技术基础。到目前，在Angewandte Chemie International Edition、Carbon、Nanoscale、Langmuir、Chemical Communications等国际著名期刊发表学术论文25篇（其中影响因子大于3的15篇，入选ESI高被引论文1篇）；申请国家发明专利13项（其中授权7项）；取得的成果系统总结后获山西省自然科学成果二等奖2项。