Pd修饰对Cdo.8Zn0.2SSiO2光催化甘油水溶液制氢性能的影响.pdf

第41卷第3期
燃料化学学报
2013年3月
Journal of Fuel Chemistry and Technology
Mar.2013
文章编号:0253-2409(2013)03-0323-05
Pd修饰对Cd。sZn.2S/SiO2光催化甘油水溶液制氢性能的影响
徐瑾',王希涛,樊灿灿2,乔婧
(1.大津理工大学管理学院,天津300384;2.天津大学化工学院,天津300072;3.天津市环境保护科学研究院,天津300191)
摘要:用等体积浸渍法制备了不同Pd负载量的Pd/Cd.sZno.2S/SiO2光催化材料,采用XRD、H2-TPR、XPS、UV- -Vis DRS和
光催化反应评价等方法对光催化材料的表面结构、光吸收性能以及光催化甘油水溶液制氢反应性能进行了考察。研究结果
表明,ZnS与CdS在SiO2表面形成了Cd.Zna2S固溶体,金属P负载未对固溶体C4sZna2S/SiO2的结构造成影响;金属Pd
修饰明显地提髙了原固溶体的光响应性能,拓展了其吸光域,增强了吸光效率。金属P修饰后,Cd8Zn。2S/SiO2的光解甘油
水溶液产氢速率显著提高,Pd负载量为0.5%的Pd/Cd.8Za:S/SiO2具有最佳的光催化甘油水溶液制氢性能,其在紫外光照
射下的氢气生成速率为831umol/h,较未负载时提高了近四倍;模拟太阳光下为153pmol/h,较未负载时提高了近两倍。
关键词:Pd修饰;Cd。sZn。2S固溶体;光催化;甘油水溶液;制氢
中图分类号:0643文献标识码:A
Effect of Pd-modification
on photocatalytic H evolution over Cdo s Zno,$/Si0 from glycerol solution
XU Jin, WANG Xi-tao, FAN Can-can, QIAO Jing
(1. Institute of Management, Tianjin University of Technology, Tianjin 300384, China
2. College of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
3. Tianjin Academy of Environmental Sciences, Tianjin 300191, China
Abstract: A series of Pd/Cdos Zno 2 S/Sio 2 photocatalysts were prepared by incipient wet impregnation, The
catalysts were characterized by XRD, H2-TPR, XPS, and Uv-vis DRS and used in the photocatalytic evolution
of H from glycerol and water mixture; the effects of Pd loading on the surface structure, photo absorption and
H evolution rate were investigated. The results showed that the chemical interaction between Zns and Cds
results in the formation of Cd s Zno, 2 S solid solution on the surface of io; after the modification with Pd the
ght absorption region of Cdo s 2 $/Sio is expanded and the photo absorption efficiency is enhanced
obviously. The loading of Pd exhibits significant influence on the rate of photocatalytic H evolution; over 0.5%
Pd/ Cdo s Zno 2 $/S0 with a Pd loading of O. 5%, the maximum hydrogen production rates under UV light
irradiation and under solar-simulated light irradiation reach 831 wmol.h and 153 wmol h, respectively, which
are almost 4 times and 2 times higher than those obtained over unmodified Cdo a 2 S/Sio2 under UV and solar
simulated light irradiation, respectively. The superior photocatalytic performance of Pd/ s Zn. S/Sio can be
partly related with the improvement of photo absorption, the enhancement in chemisorption and activation of H O
and the increase in separation efficiency of photo induced electron-hole arising from the Pd modification
Key words: Pd-modified; Cdo R Zno S solid solution; photocatalysis; glycerol solution; H2 production
利用太阳能光催化分解水制氢是太阳能转化与合催化剂表现出比单一-硫化物催化剂更为优异的性
储存的有效途径之ー一-?,研制高效稳定的可见光能。而在CdS-ZnS复合半导体表面沉积贵金属粒
催化剂对提高太阳能的转化效率有重要意义。在众子不仅可起到光敏剂的作用,增加半导体对光的吸
多光催化剂中,CdS属窄带半导体材料,由于能级接收,还可起到传输电子和空穴的作用,阻止电子一空
近太阳光谱,其在光催化领域的应用引起人们的广穴对的复合;同时也可作为氢离子还原反应的活性
泛关注。但是,纯CdS半导体材料光生载流子易复位,进而提高复合半导体的光催化制氢活性。
合,其光催化效率较低。通过与宽禁带半导体材料
因此,本实验采用等体积浸渍法制备了负载型
复合或贵金属沉积对纯CdS进行改性,可明显改善 Cd,Zn_2S/SiO2固溶体,考察了贵金属Pd修饰对
其光催化性能。研究表明1,8,CdS与ZnS复合可 Cdo s Zn2S/SiO2复合半导体材料光催化甘油水溶
以形成固溶体,能有效提高电荷分离效率,从而使复液铏氢性能的影响。
收稿日期:2012-08-06;修回日期:2012-1027。
基金项目:国家自然科学基余(20806059,21276190)。
联系作者:王希涛,E-mail:wangxt@tiu,edu.cn;Tel:02-27402972。