Hybridization of g-C3N4 quantum dots with 1D branched TiO2 fiber for efficient visible light-driven photocatalytic hydrogen generation. (18th May 2020)

• Record Type: Journal Article
• Authors: Nasir, Muhammad Salman; Yang, Guorui; Ayub, Iqra; Wang, Xiaojun; Wang, Silan; Yan, Wei
• Is Part Of: International journal of hydrogen energy. Volume 45:Number 27(2020)
• Page Start: 13994
• Page End: 14005
• Publication Date: 2020-05-18
• Subjects: Photocatalyst -- Hydrogen -- Quantum dots -- Hierarchical -- Visible; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2020.03.129
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The hybrid 1D branched TiO2 loaded with g-C3 N4 QDs was successfully fabricated that plays a significant role in photocatalysis. The 1D branched TiO2 prepared by electrospinning followed by alkali-hydrothermal process, and g-C3 N4 QDs were grafted over it by a chemical vapor deposition method. The composite display enhancement in photocatalytic hydrogen evolution is about 10.57 mmol. g −1 .h −1 in comparison to the g-C3 N4 sample that only produces 0.32 mmol. g −1 .h −1 while the HBTiO2 sample evolved a negligible amount of hydrogen under visible light. The composite sample shows quantum efficiency for HER at 420 nm light is 18.6% that is much higher than the other two samples. The specific surface area of the composite sample is 92.39 m 2 g -1 that is about 13 times more than bulk g-C3 N4. The bandgap of HBTiO2 /g-C3 N4 QDs, g-C3 N4, and HBTiO2 samples calculated as 2.71 eV, 2.67eV, and 3.24eV, respectively. The TRPL spectra imply that the duration of the lifetime of composite becomes longer which effectually overwhelm the electron-hole recombination. The 1D branched TiO2 fiber reduces the charge recombination by fast transfer of electron while g-C3 N4 QDs facilitate the visible light absorption by improving the optical properties. The formation of the type II heterostructure system remarkably promotes the separation and transfer of electron holes and facilitates the photo-reduction reaction. Graphical abstract: Image 1 Highlights: The in situ hierarchically branched TiO2 fiber was fabricated. The successfully loading of g-C3 N4 Quantum Dots (QD's) on the branched TiO2 fiber and developed a heterojunction system. The composite HBTiO2 /g-C3 N4 QD's generated 33 times more hydrogen than bulk g-C3 N4 under visible light. The quantum efficiency of the composite HBTiO2 /g-C3 N4 QD's was calculated about 18.6% at 420 nm. The reaction mechanism for the photocatalytic hydrogen evolution was proposed.