PbS插层K4Nb6O17复合物的制备及其光催化制氢活性

采用固相法合成层状半导体K4Nb6O17,通过层间离子交换反应、胺插入反应以及硫化反应制备了纳米PbS插层的K4Nb6O17复合光催化剂(记作K4Nb6O17/PbS).利用X射线衍射(XRD),场发射扫描电镜(SEM),X射线荧光光谱仪(XRF),紫外可见漫反射(UV-Vis)和分子荧光光谱(PL)等技术对其进行表征.考察了催化剂在Na2SO3和Na2S为牺牲剂的光催化制氢活性.结果表明,PbS的插层拓展了K4Nb6O17对可见光的响应,催化制氢活性也有明显提高.在紫外光和可见光下3 h产氢量分别达到123.94和0.66 mmol/(g cat).最后讨论了插层复合催化剂光生电荷转移的机理.

Synthesis of PbS Intercalated K4Nb6O17 Composite and Its Photocatalytic Activity for Hydrogen Production

The layered compound K4Nb6O17 was prepared via high temperature solid reaction,and PbS intercalated K4Nb6O17(designated as K4Nb6O17/PbS) photocatalyst was synthesized via direct ion exchange,alkylamines intercalation and sulfurization procedures.The as-prepared samples were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM),ultraviolet-visible diffuse reflection spectra(UV-Vis) and photoluminescence measurement(PL),energy dispersive X-ray detector(EDS) and X-ray fluorescence spectrometer(XRF).The photocatalytic performance of these catalysts for hydrogen production was also investigated in the presence of Na2S and Na2SO3sacrificial reagents.The absorption edge of K4Nb6O17 shifted to visible light region after the intercalation of PbS.K4Nb6O17/PbS photocatalysts exhibit higher activities for photocatalytic hydrogen production under both UV light and visible light irradiation,and the amounts of hydrogen produced are 123.94 mmol/(g cat) and 0.66 mmol/(g cat) after 3 h irradiation,respectively.The mechanism of charge separation is also discussed.