Abstract
Halogens, as typical non-metal dopants, have attracted intensive interests for developing highly active photocatalysts. However, the essential factors and underlying mechanism of halogen modification are still unclear. Herein, we systematically report the development of halogen (F, Cl and Br)-doped covalent triazine-based frameworks (CTFs) via a facile thermal treatment of CTFs and an excess of ammonium halide. The introduction of halogen atoms endowed CTFs with multiple superior effects such as improved optical absorption, promoted charge migration, narrowed band gaps and tuned band positions. The newly developed halogen-doped CTFs showed remarkable photocatalytic activities for H2 evolution under visible-light irradiation. Notably, the most enhanced photocatalytic performance was obtained with Cl-doped CTFs, which exhibited 7.1- and 2.4-fold enhancements compared to un-doped CTFs and Cl-doped g-C3N4, respectively. The electronegativity and atomic radius of the halogen atoms affected the modification of the optical and electronic properties, leading to different photocatalytic performances of F-, Cl- and Br-doped CTFs. The conclusions presented in this work will provide some new insights into the understanding of the doping effect for the improvement of the photocatalytic activity of halogen-doped CTF photocatalysts.
Highlights
Conjugated polymer semiconductors have been investigated as promising photocatalysts due to their diverse molecular structures, high surface areas and adjustable electronic band structures.[1,2,3] conjugated polymers are mainly composed of abundant carbon, nitrogen and oxygen elements and are more economical than conventional inorganic semiconductors
The type IV adsorption–desorption isotherms with a hysteresis loop for the Covalent triazine-based frameworks (CTFs)-1 and CTFX samples indicated the presence of a mesoporous structure (Fig. S2†)
The similar speci c surface areas and pore volumes of the CTF-1 and CTFX samples manifested that the effects of the surface area and pore structure on the photocatalytic activity can be neglected
Summary
Conjugated polymer semiconductors have been investigated as promising photocatalysts due to their diverse molecular structures, high surface areas and adjustable electronic band structures.[1,2,3] conjugated polymers are mainly composed of abundant carbon, nitrogen and oxygen elements and are more economical than conventional inorganic semiconductors. A systematic investigation of the doping effect in terms of the electronic structure, optical properties and charge carrier separation/transfer in halogendoped CTFs is urgently required for a better understanding of their enhancement in photocatalytic activity.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
