title: Photoelectrochemical Conversion from Graphitic C3N4 Quantum Dot Decorated Semiconductor Nanowires.
abstract: Despite the recent progress of developing graphitic carbon nitride (g-C3N4) as a metal-free photocatalyst, the synthesis of nanostructured g-C3N4 has still remained a complicated and time-consuming approach from its bulk powder, which substantially limits its photoelectrochemical (PEC) applications as well as the potential to form composites with other semiconductors. Different from the labor-intensive methods used before, such as exfoliation or assistant templates, herein, we developed a facile method to synthesize graphitic C3N4 quantum dots (g-CNQDs) directly grown on TiO2 nanowire arrays via a one-step quasi-chemical vapor deposition (CVD) process in a homemade system. The as-synthesized g-CNQDs uniformly covered over the surface of TiO2 nanowires and exhibited attractive photoluminescence (PL) properties. In addition, compared to pristine TiO2, the heterojunction of g-CNQD-decorated TiO2 nanowires showed a substantially enhanced PEC photocurrent density of 3.40 mA/cm(2) at 0 V of applied potential vs Ag/AgCl under simulated solar light (300 mW/cm(2)) and excellent stability with ∼82% of the photocurrent retained after over 10 h of continuous testing, attributed to the quantum and sensitization effects of g-CNQDs. Density functional theory calculations were further carried out to illustrate the synergistic effect of TiO2 and g-CNQD. Our method suggests that a variety of g-CNQD-based composites with other semiconductor nanowires can be synthesized for energy applications.
authors.affiliation: Laboratory of Advanced Materials, Department of Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University , Shanghai 200433, China.
authors.forename: Tiance
authors.initials: T
authors.lastname: An
authors.affiliation: Laboratory of Advanced Materials, Department of Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University , Shanghai 200433, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Tang
authors.affiliation: Key Laboratory of Computational Physical Sciences, Ministry of Education, State Key Laboratory of Surface Physics, and Department of Physics, Fudan University , Shanghai 200433, China.
authors.forename: Yueyu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Laboratory of Advanced Materials, Department of Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University , Shanghai 200433, China.
authors.forename: Yingzhou
authors.initials: Y
authors.lastname: Quan
authors.affiliation: Key Laboratory of Computational Physical Sciences, Ministry of Education, State Key Laboratory of Surface Physics, and Department of Physics, Fudan University , Shanghai 200433, China.
authors.forename: Xingao
authors.initials: X
authors.lastname: Gong
authors.affiliation: Department of Chemistry, College of Science, King Saud University , Riyadh 11451, Saudi Arabia.
authors.forename: Abdullah M
authors.initials: AM
authors.lastname: Al-Enizi
authors.affiliation: Materials Science and Technology Program, College of Arts and Sciences, Qatar University , Doha, Qatar.
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Elzatahry
authors.affiliation: Laboratory of Advanced Materials, Department of Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University , Shanghai 200433, China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Laboratory of Advanced Materials, Department of Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University , Shanghai 200433, China.
authors.forename: Gengfeng
authors.initials: G
authors.lastname: Zheng
keywords: TiO2 nanowires; carbon nitride quantum dot; chemical vapor deposition; photoelectrochemical conversion; photoluminescence