Hollow Carbon Sphere‐Modified Graphitic Carbon Nitride for Efficient Photocatalytic H2 Production

• Published in: Chemistry : a European journal 2021-12, Vol.27 (68), p.16879-16888
• Main Authors: Li, Jinghua, Xiong, Lunqiao, Luo, Bing, Jing, Dengwei, Cao, Jiamei, Tang, Junwang
• Format: Article
• Language: English
• Subjects: Carbon; Carbon nitride; Charge transfer; Chemistry; graphitic carbon nitride; hollow carbon nanospheres; Hydrogen production; Irradiation; Light irradiation; metal-free photocatalysts; Nanospheres; Nanostructure; Photocatalysis; Photocatalysts; Photoelectrons; Recombination; Urea
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202102330

A novel hybrid photocatalyst composed of hollow carbon nanospheres (NCS) and graphitic carbon nitride (CN) curly nanosheets has been prepared by the calcination of a NCS precursor and freeze‐dried urea. The optimized photocatalyst exhibits an efficient photocatalytic performance under visible light irradiation with a highest H2 generation rate of 3612.3 μmol g−1 h−1, leading to an apparent quantum yield of 10.04 % at 420 nm, five times higher than the widely reported benchmark photocatalyst CN (2.01 % AQY). The materials characterization shows that NCS‐modified CN curly nanosheets can promote photoelectron transfer and suppress charge recombination through their special coupling interface and NCS as an electron acceptor, which significantly improves the photocatalytic efficiency. Thus, this study provides an efficient strategy for the design of highly efficient photocatalyst, particularly suitable for a totally metal‐free photocatalytic system. Spheres of influence: Hollow carbon nanospheres implanted in the surface plane of carbon nitride curly nanosheets were synthesized by thermal polymerization of freeze‐dried urea and a NCS precursor. When the CN/NCS photocatalyst is irradiated by visible light, electron‐hole pairs are generated in CN, then the electrons in the conduction bands of CN are transferred to the NCS. This results in efficient photocatalytic performance under visible light irradiation with a high H2 production rate and notable quantum yield.