title: Carbon nanodot decorated graphitic carbon nitride: new insights into the enhanced photocatalytic water splitting from ab initio studies.
abstract: Interfacing carbon nanodots (C-dots) with graphitic carbon nitride (g-C3N4) produces a metal-free system that has recently demonstrated significant enhancement of photo-catalytic performance for water splitting into hydrogen [Science, 2015, 347, 970-974]. However, the underlying photo-catalytic mechanism is not fully established. Herein, we have carried out density functional theory (DFT) calculations to study the interactions between g-C3N4 and trigonal/hexagonal shaped C-dots. We find that hybrid C-dots/g-C3N4 can form a type-II van der Waals heterojunction, leading to significant reduction of band gap. The C-dot decorated g-C3N4 enhances the separation of photogenerated electron and hole pairs and the composite's visible light response. Interestingly, the band alignment of C-dots and g-C3N4 calculated by the hybrid functional method indicates that C-dots act as a spectral sensitizer in hybrid C-dots/g-C3N4 for water splitting. Our results offer new theoretical insights into this metal-free photocatalyst for water splitting.
authors.affiliation: School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), Garden Point Campus, QLD 4001, Brisbane, Australia. aijun.du@qut.edu.au.
authors.forename: Guoping
authors.initials: G
authors.lastname: Gao
authors.affiliation: School of Chemical Engineering, University of Adelaide, Adelaide, SA 5005, Australia.
authors.forename: Yan
authors.initials: Y
authors.lastname: Jiao
authors.affiliation: School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), Garden Point Campus, QLD 4001, Brisbane, Australia. aijun.du@qut.edu.au.
authors.forename: Fengxian
authors.initials: F
authors.lastname: Ma
authors.affiliation: School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), Garden Point Campus, QLD 4001, Brisbane, Australia. aijun.du@qut.edu.au.
authors.forename: Yalong
authors.initials: Y
authors.lastname: Jiao
authors.affiliation: School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), Garden Point Campus, QLD 4001, Brisbane, Australia. aijun.du@qut.edu.au.
authors.forename: Eric
authors.initials: E
authors.lastname: Waclawik
authors.affiliation: School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), Garden Point Campus, QLD 4001, Brisbane, Australia. aijun.du@qut.edu.au.
authors.forename: Aijun
authors.initials: A
authors.lastname: Du