Boosting the visible-light photoelectrochemical performance of C3N4 by coupling with TiO2 and carbon nanotubes: An organic/inorganic hybrid photocatalyst nanocomposite for photoelectrochemical water spitting. (6th November 2020)

• Record Type: Journal Article
• Authors: Chaudhary, Deepti; Kumar, Sunil; Khare, Neeraj
• Is Part Of: International journal of hydrogen energy. Volume 45:Number 55(2020)
• Page Start: 30091
• Page End: 30100
• Publication Date: 2020-11-06
• Subjects: C3N4 -- Carbon nanotubes -- Kelvin probe force microscopy -- Photoelectrochemical water splitting; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2020.08.059
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Developing photoanode with proficient sunlight harvesting, stability as well as enhancing the electron injection across the interface remains a major challenge in the photoelectrochemical water splitting strategy to generate hydrogen. Herein, we design and fabricate an organic/inorganic TiO2 /C3 N4 /CNT photoanode by a hydrothermal technique which exhibits much enhanced photoelectrochemical properties. The TiO2 /C3 N4 /CNT photoanode exhibits a photocurrent density of 2.94 mA/cm 2, which is ~6.4 time higher than pristine graphitic carbon nitride (C3 N4 ) at an applied bias potential of 0.6 V vs. Ag/AgCl. The excellent photoelectrochemical performance benefits from the impactful migration of photo-induced electrons at the TiO2 /C3 N4 interface from C3 N4 to TiO2 and their intimate interface contact with CNT. Kelvin probe force microscopy result shows a smaller interface barrier height (~10 meV) between TiO2 and C3 N4, suggesting that electrons transport is favored through TiO2 /C3 N4 interfaces in a ternary photoanode. The TiO2 /C3 N4 /CNT photoanode exhibited an onset potential of 0.25 V vs. Ag/AgCl which is much lower compared to pristine C3 N4. The electrochemical impedance spectroscopy results also confirmed the enhanced electron injection across the interface in a ternary photoanode. These results demonstrate a promising approach to develop a highly proficient and visible light active photoanode with excellent stability for renewable energy applications. Graphical abstract: Image 1 Highlights: An Organic/Inorganic ternary photoanode was synthesized by the hydrothermal method. KPFM results shows that electron transport is favored through TiO2 /C3 N4 interfaces. The ternary photoanode exhibits ~6.4 time higher photocurrent density than C3 N4 . The ternary photoanode exhibited excellent photostability.