In situ fabrication of 2D/3D g-C3N4/Ti3C2 (MXene) heterojunction for efficient visible-light photocatalytic hydrogen evolution

• Published in: Applied surface science Vol. 515; p. 145922
• Main Authors: Li, Jinmao, Zhao, Li, Wang, Shimin, Li, Jin, Wang, Guohong, Wang, Juan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.06.2020
• Subjects: g-C3N4; H2-evolution; MXene; Photocatalytic mechanism; Ti3C2; g-C3N4; H2-evolution; Photocatalytic mechanism; Ti3C2; MXene
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2020.145922

[Display omitted] •The g-C3N4/Ti3C2 hybrid is in-situ prepared by a one-step calcination method.•The lamellar g-C3N4 on Ti3C2 surface provides a wide and intimate interface.•An improved H2 evolution performance is achieved by g-C3N4/Ti3C2 hybrid.•The DFT and Kelvin probe are used to clarify the electron transfer mechanism.•A possible photocatalytic enhancement mechanism is proposed. Photocatalytic water splitting has been recognized as a hopeful route for producing hydrogen. To design a catalyst with high separation efficiency of photo-induced carriers is critical for boosting hydrogen product rate. In this work, we report an in-situ construction strategy for g-C3N4/Ti3C2 composites by one-step calcination process. And a unique 2D/3D structure was obtained through the uniform distribution of lamellar g-C3N4 on Ti3C2 surface. The photocatalytic hydrogen product rate of optimized g-C3N4/Ti3C2 composite was above six times higher than that of pristine g-C3N4 under visible light irradiation. For purpose of clarifying the potentially photocatalytic mechanism, a series of tests involving Kelvin probe measurements and the density functional theory (DFT) calculations were executed. The results confirmed that the Schottky junction between g-C3N4 and Ti3C2 efficiently restrains the recombination of photo-induced carriers. Furthermore, the excellent conductivity of Ti3C2 and the intimate interface of components corporately facilitate the electron immigration. This work provides a new approach to the fabrication of highly efficient g-C3N4/Ti3C2 composite for photoconversion applications.