C=C π Bond Modified Graphitic Carbon Nitride Films for Enhanced Photoelectrochemical Cell Performance

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

18 Scopus Citations
View graph of relations

Author(s)

  • Juncao Bian
  • Lifei Xi
  • Jianfu Li
  • Ze Xiong
  • Kathrin M. Lange
  • Jinyao Tang
  • Menny Shalom

Detail(s)

Original languageEnglish
Pages (from-to)1005-1012
Journal / PublicationChemistry - An Asian Journal
Volume12
Issue number9
Publication statusPublished - 4 May 2017

Abstract

Applications of graphitic carbon nitride (g-CN) in photoelectrochemical and optoelectronic devices are still hindered due to the difficulties in synthesis of g-CN films with tunable chemical, physical and catalytic properties. Herein we present a general method to alter the electronic and photoelectrochemical properties of g-CN films by annealing. We found that N atoms can be removed from the g-CN networks after annealing treatment. Assisted by theoretical calculations, we confirm that upon appropriate N removal, the adjacent C atoms will form new C=C π bonds. Detailed calculations demonstrate that the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) are located at the structure unit with C=C π bonds and the electrons are more delocalized. Valence band X-ray photoelectron spectroscopy spectra together with optical absorption spectra unveil that the structure changes result in the alteration of the g-CN energy levels and position of band edges. Our results show that the photocurrent density of the annealed g-CN film is doubled compared with the pristine one, thanks to the better charge separation and transport within the film induced by the new C=C π bonds. An ultrathin TiO2 film (2.2 nm) is further deposited on the g-CN film as stabilizer and the photocurrent density is kept at 0.05 mA cm−2 at 1.23 V versus reversible hydrogen electrode after two-cycle stability assessment. This work enables the applications of g-CN films in many electronic and optoelectronic devices.

Research Area(s)

  • annealing, electron delocalization, graphitic carbon nitride films, photoelectrochemical cell, pi bonds

Citation Format(s)

C=C π Bond Modified Graphitic Carbon Nitride Films for Enhanced Photoelectrochemical Cell Performance. / Bian, Juncao; Xi, Lifei; Li, Jianfu; Xiong, Ze; Huang, Chao; Lange, Kathrin M.; Tang, Jinyao; Shalom, Menny; Zhang, Rui-Qin.

In: Chemistry - An Asian Journal, Vol. 12, No. 9, 04.05.2017, p. 1005-1012.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal