Manipulating photocatalytic pathway and activity of ternary Cu2O/(001)TiO2@Ti3C2Tx catalysts for H2 evolution: Effect of surface coverage. (15th November 2019)

• Record Type: Journal Article
• Authors: Peng, Chao; Xu, Wenkang; Wei, Ping; Liu, MinChao; Guo, Lin; Wu, Panpan; Zhang, Kun; Cao, Yonghai; Wang, Hongjuan; Yu, Hao; Peng, Feng; Yan, Xiqiang
• Is Part Of: International journal of hydrogen energy. Volume 44:Number 57(2019)
• Page Start: 29975
• Page End: 29985
• Publication Date: 2019-11-15
• Subjects: MXene -- Cu2O/(001)TiO2@Ti3C2Tx -- Hydrogen evolution -- Surface coverage -- Photocatalytic mechanism; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2019.09.190
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: A Cu2 O/(001)TiO2 @Ti3 C2 Tx photocatalyst was synthesized via a wet-chemistry reduction method by N, N-dimethylformamide (DMF). By scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD), it was revealed that the surface coverage of photocatalyst increased with the loading amount of Cu2 O, while the particle size of Cu2 O did not change significantly. The photocatalytic activity and mechanism of ternary Cu2 O/(001)TiO2 @Ti3 C2 Tx photocatalyst heavily depend on the surface coverage of copper species. When the surface coverage of photocatalyst by Cu2 O was low, the Ti3 C2 Tx acted as hole reservoir. Cu2 O was firstly reduced in situ to metallic copper by excited electrons. Then the reverse movement of carriers enabled the spatial separation of photogenerated electron-hole pairs, and afforded relatively high hydrogen evolution (more than 1100 μmol h −1 (g CuOx TiO2 ) −1 ). When the coverage of Cu2 O on (001)TiO2 @Ti3 C2 Tx was too high at high loading amounts, Ti3 C2 Tx failed to play the role of hole trapping. Under that circumstance, the photocatalytic reaction follows p-n junction mechanism, leading to low hydrogen productivity. The results here shed light on the relationship between structure and activity of Cu2 O/(001)TiO2 @Ti3 C2 Tx, which was conducive to the development of the MXene-based photocatalysts. Graphical abstract: Image 1 Highlights: A Cu2 O–TiO2 –Ti3 C2 Tx ternary catalyst fabricated by a solvent reduction method. The loading amount and surface coverage of Cu2 O can be easily adjusted. The hydrogen evolution activity can be manipulated by the amount of copper species. The photocatalytic reaction mechanism depends on the surface coverage of Cu2 O.