title: Origin of the enhanced visible-light photocatalytic activity of CNT modified g-C3N4 for H2 production.
abstract: Graphitic carbon nitride (g-C3N4) hybridized with a small number of multi-walled carbon nanotubes (CNT) was synthesized using cyanamide as precursor. The optimal CNT content is found to be ∼0.2 wt% in the composite, which displays a 2.4-fold enhancement in photocatalytic water splitting over pure g-C3N4. Characterizations by a series of joint techniques including Raman spectra, UV/vis diffuse reflectance spectra, steady and time-resolved fluorescence emission spectra, and photocurrent responses were carried out, aiming to reveal the determinative factor for the improved visible-light response. Our results indicate that the increased photoactivity originates from the enhanced charge-transfer effect due to the intimate interactions between g-C3N4 and conjugated CNT. The presence of CNT in the hybrids is beneficial for improving electron-hole separation on the excited g-C3N4 by prolonging the lifetimes of charge carriers and improving the population distribution of short-lived and long-lived charge carriers.
authors.affiliation: Key Laboratory for Functional Materials of Fujian Higher Education, College of Materials Science and Engineering, Huaqiao University, Xiamen 361021, P. R. China. ylchen@hqu.edu.cn.
authors.forename: Yilin
authors.initials: Y
authors.lastname: Chen
authors.forename: Jianghua
authors.initials: J
authors.lastname: Li
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Hong
authors.forename: Biao
authors.initials: B
authors.lastname: Shen
authors.forename: Bizhou
authors.initials: B
authors.lastname: Lin
authors.forename: Bifen
authors.initials: B
authors.lastname: Gao