CAJ | 학술논문

采用原位碳热还原法制备了硼掺杂的β-SiC (BxSiC)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.
채용원위탄열환원법제비료붕참잡적β-SiC (BxSiC)광최화제，병고찰료기가견광하광최화분해수제경적성능.이용X사선연사의、X사선광전자능보、소묘전경급자외-가견흡수광보등측시방법대소제비최화제적정형、형모、표면성질급능대결구진행료표정.분석결과표명，붕원자참잡진입SiC정격병취대료Si위점，재개대상방형성료천수주능급，종이도치료대극관변착.천수주능급작위공혈적포획중심가억제광생전자화공혈적복합.인차，여SiC상비，붕참잡SiC광최화제재가견광하최화분해수산경적활성대대제고.당B/Si적마이비위0.05시，붕참잡SiC표현출최고적광최화산경활성.
Boron-doped β-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 shal ow acceptor level above the valence band of SiC, resulting in a narrowed band gap energy. The shal ow 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.