摘要
采用化学腐蚀法制备碳化硅(SiC)量子点荧光材料,对其进行Fourier变换红外光谱分析及X射线粉末衍射结构解析,研究了SiC量子点的晶体结构,而后基于密度泛函理论的CASTEP平面波模守恒赝势对SiC量子点表面不同功能团的吸附机制进行计算模拟。结果表明:SiC量子点属于面心立方晶系,修正后的点阵参数为:a=b=c=0.434 8 nm,α=β=γ=90°,空间群为F-43m,晶型为3C-SiC,每单胞含化学式Z=4。Rietveld精修的2个主要可靠因子分别为:R_p=10.82%,R_(wp)=14.72%。–COOH、–OH功能团能够在SiC量子点表面形成稳定的化学键结合,键能分别为2.65、5.09 eV,并对吸附后构型的态密度、电子密度分布及其成键机理进行了分析探讨。
Silicon carbide quantum dots （SiC-QDs） fluorescent materials were prepared via a simple chemical etching method. The crystal structure and physico-chemical characteristics on the surface of SiC-QDs were investigated by X-ray powder diffraction and Fourier transform infrared spectroscopy （FTIR）.The adsorption mechanism of different SiC surface functional groups were simulated based on the CASTEP plane wave model with the density functional theory and the conservation of the pseudo potential. The results show that for the face-centered cubic crystal system （FCC） of SiC-QDs, the final modified unit-cell parameters are a=b=c=0.434 8 nm and α=β=γ=90°, F-43m of space group, 3C-SiC of crystal type, every single cell contained chemical formula Z=4. For -COOH, -OH functional groups, the reliable factors of Rietveld refinement are 10.82% and 14.72%, which can result in the formation of a stable chemical bonds on the surface of the SiC-QDs with bond energy of 2.65 and 5.09 eV, respectively. In addition, the density of states, the electron density distribution and the bonding mechanism of the configuration after adsorption were also analyzed.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2016年第5期733-739,共7页
Journal of The Chinese Ceramic Society
基金
山东省科技发展计划项目(2014GGX102012)
中国博士后科学基金(2013M53163)项目
山东省现代农业产品技术体系果品创新团队专项经费资助项目
关键词
碳化硅量子点
X射线粉末衍射
晶体结构
化学吸附
silicon carbide quantum dots
X-ray powder diffraction
crystal structure
chemical adsorption
