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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 β-SiC (Bx SiC) photocatalyst was prepared by in-situ carbothermal reduction method and the photocatalytic performance of photocatalytic decomposition of water to hydrogen in visible light was investigated. X-ray diffractometry, X-ray photoelectron spectroscopy, The morphology, surface properties and band structure of the prepared catalyst were characterized by scanning electron microscopy and UV-Vis absorption spectroscopy.The results show that the boron atom doping into the SiC lattice and replacing the Si site , Forming a shallow acceptor level above the valence band, resulting in a narrowing of the bandgap width.As a hole-trapping center, shallow acceptor levels can suppress the recombination of photogenerated electrons and holes.Thus, compared with SiC, The activity of boron-doped SiC photocatalysts in the catalytic decomposition of aquatic hydrogen under visible light is greatly increased.When the B / Si molar ratio is 0.05, the boron-doped SiC exhibits the highest photocatalytic hydrogen production activity.