摘要
在空气中直接加热三聚氰胺和氧化石墨烯(GO)的混合物制备了g-C3N4/r GO杂化催化剂.实验结果表明,混合物中的g-C3N4保留了石墨型氮化碳原始的特征结构,g-C3N4和还原的氧化石墨烯(rG O)之间的异质结主要通过π-π作用构筑.当原料中三聚氰胺/GO的质量比是800/1时,所得催化剂对罗丹明B的催化作用最强,其一阶动力学常数是纯g-C3N4的2.6倍.这种强化作用主要是由于r GO促进了光生电子-空穴对的分离.此外,g-C3N4/r GO还表现出显著的p H值敏感特性,催化降解速率随p H的降低而增加.当p H=1.98时,其一阶动力学常数是纯g-C3N4的8.6倍.这是由于酸性条件下质子(H+)消耗掉光生电子,促进了空穴对罗丹明B的氧化作用,其中r GO充当了一个快速的光生电子转移平台.
A hybrid catalyst of g-C3N4（graphitic carbon nitride）/rG O（reduced graphene oxide） was prepared by directly heating a mixture of melamine and GO in air. g-C3N4 in the hybrid retained the structure of pristine g-C3N4, and the heterojunction between g-C3N4 and rG O was formed by π-π interaction. The highest photocatalytic efficiency for the degradation of rhodamine B（RhB） was with the melamine/GO mass ratio of 800/1, with a first order rate constant 2.6 times that of pristine g-C3N4. The enhanced photocatalytic activity was assigned to the rG O-promoted separation of photo-generated electron（e–）-hole（h＋） pairs. In addition, the photocatalytic activity of g-C3N4/rG O was pH sensitive with a much increased photodegrading rate at low pH values. The first order rate constant was 8.6 times that of pristine g-C3N4 at pH = 1.98. The pH sensitive behavior resulted from the promoted oxidation of h＋ with RhB by the consumption of e- with the reaction of proton（H＋） in which rG O acted as a good platform for transferring e– through its atomic sheets.
出处
《催化学报》
SCIE
EI
CAS
CSCD
北大核心
2015年第7期1009-1016,共8页
基金
supported by the National Natural Science Foundation of China(51073172)
the Hunan Provincial Natural Science Foundation for Distinguished Young Scholars(14JJ1001)~~
关键词
氮化碳
氧化石墨烯
光催化
P
H敏感性
罗丹明B降解
Graphitic carbon nitride Graphene oxide Photocatalysis pH-sensitivity Rhodamine B degradation
作者简介
通讯联系人．电话：（0731）84574786—811；传真：（0731）84574250；电子信箱：chuzy@nudt．edu．cn
