硼掺杂SiC的制备、表征及其可见光分解水产氢性能(英文)  

Synthesis and Characterization of Boron-Doped SiC for Visible Light Driven Hydrogen Production

作　　者：董莉莉 王英勇[1] 童希立[1] 靳国强[1] 郭向云[1] 

机构地区：[1]中国科学院山西煤炭化学研究所,煤转化国家重点实验室,太原030001 [2]中国科学院大学,北京100049

出　　处：《物理化学学报》2014年第1期135-140,共6页Acta Physico-Chimica Sinica

基　　金：The project was supported by the National Natural Science Foundation of China(21173251,21203233);Innovation Fund of Institute of Coal Chemistry,Chinese Academy of Sciences(Y1SC6R1991);State Key Laboratory of Coal Conversion,China(2013BWZ006)~~

摘　　要：采用原位碳热还原法制备了硼掺杂的β-SiC(Bx SiC)光催化剂,并考察了其可见光下光催化分解水制氢的性能.利用X射线衍射仪、X射线光电子能谱、扫描电镜及紫外-可见吸收光谱等测试方法对所制备催化剂的晶型、形貌、表面性质及能带结构进行了表征.分析结果表明,硼原子掺杂进入SiC晶格并取代了Si位点,在价带上方形成了浅受主能级,从而导致了带隙宽变窄.浅受主能级作为空穴的捕获中心可抑制光生电子和空穴的复合.因此,与SiC相比,硼掺杂SiC光催化剂在可见光下催化分解水产氢的活性大大提高.当B/Si的摩尔比为0.05时,硼掺杂SiC表现出最高的光催化产氢活性.Boron-doped E-SiC （BxSiC） photocatalysts were prepared by in-situ carbothermal reduction, and their photocatalytic performances for H2 evolution under visible light irradiation were investigated. The crystal structure, surface property, morphology, and band gap structure of the BxSiC photocatalysts were studied using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and ultraviolet-visible absorption spectroscopy. The characterization results indicate that B atoms have doped into the SiC lattice and substituted Si sites, leading to the formation of a shallow acceptor level above the valence band of SiC, resulting in a narrowed band gap energy. The shallow acceptor level acts as a hole trap, preventing the recombination of photo-excited electrons and holes. Therefore, the photocatalytic H2 evolution activity of B-doped SiC was greatly improved compared with that of SiC. The highest hydrogen evolution rate was obtained when the B/Si molar ratio was 0.05.

关 键 词：Β-SIC 硼掺杂 光催化 产氢 可见光 

分 类 号：O643.36[理学—物理化学]