Graphitic carbon nitride (g-C3N4)-Pt-TiO2 nanocomposite as an efficient photocatalyst for hydrogen production under visible light irradiation
Graphitic carbon nitride (g-C3N4)-Pt-TiO2 nanocomposite as an efficient photocatalyst for hydrogen production under visible light irradiation
复制标题
石墨氮化碳（g-C3N4）-Pt-TiO2纳米复合材料作为可见光照射下高效产氢光催化剂
DOI：
10.1039/c2cp42484c
复制
发表时间：
2012-01-01
影响因子：
3.3
通讯作者：
Zan, Ling
中科院分区：
文献类型：
--
作者：
Chai, Bo;Peng, Tianyou;Zan, Ling
以尿素为原料，采用热解法制备了多孔石墨氮化碳（g-C3 N4），然后通过化学吸附和煅烧工艺制备了g-C3 N4-Pt-TiO 2纳米复合材料。采用X射线衍射、X射线光电子能谱、紫外-可见漫反射吸收光谱和电子显微镜对产物进行了表征。结果发现，将TiO 2与上述g-C3 N4偶联，以及质量比为70：1的g-C3 N4-Pt-TiO 2复合物，可以显著提高可见光诱导光催化析氢速率。30在可见光照射下具有最大的光活性和优异的光稳定性，并且g-C3 N4-TiO 2的稳定光电流比裸g-C3 N4高约1.5倍。上述实验结果表明，由于Pt-TiO 2和g-C3 N4之间存在紧密的界面连接和协同效应，光生电子和空穴在空间上有效分离，g-C3 N4的光生电子可以定向迁移到Pt-TiO 2，有利于延缓电荷复合，提高光活性。
Porous graphitic carbon nitride (g-C3N4) was prepared by a simple pyrolysis of urea, and then a g-C3N4-Pt-TiO2 nanocomposite was fabricated via a facile chemical adsorption followed by a calcination process. The obtained products were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance absorption spectra, and electron microscopy. It is found that the visible-light-induced photocatalytic hydrogen evolution rate can be remarkably enhanced by coupling TiO2 with the above g-C3N4, and the g-C3N4-Pt-TiO2 composite with a mass ratio of 70 : 30 has the maximum photoactivity and excellent photostability for hydrogen production under visible-light irradiation, and the stable photocurrent of g-C3N4-TiO2 is about 1.5 times higher than that of the bare g-C3N4. The above experimental results show that the photogenerated electrons of g-C3N4 can directionally migrate to Pt-TiO2 due to the close interfacial connections and the synergistic effect existing between Pt-TiO2 and g-C3N4 where photogenerated electrons and holes are efficiently separated in space, which is beneficial for retarding the charge recombination and improving the photoactivity.