Graphitic carbon nitride nanosheet for photocatalytic hydrogen production: The impact of morphology and element composition

• Published in: Applied surface science 2017-01, Vol.391, p.369-375
• Main Authors: Zhang, Zhao, Zhang, Yijie, Lu, Luhua, Si, Yanjie, Zhang, Si, Chen, Ying, Dai, Kai, Duan, Ping, Duan, Limei, Liu, Jinghai
• Format: Article
• Language: English
• Subjects: Element composition; Graphitic carbon nitride; Morphology; Photocatalytic hydrogen evolution; Specific surface area
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2016.05.174

•g-C3N4 with tunable morphology was prepared by varying pyrolysis time.•g-C3N4 showed reduced recombination of photogenerated electrons and holes.•g-C3N4 showed enhanced photocatalytic hydrogen evolution activity. The intrinsic morphology and basal plane defects on g-C3N4 nanosheet have important influences on its electronic structures and photocatalytic activity. In this work, we report extending thermal treatment time of g-C3N4 at 550°C not only change the morphology of g-C3N4 but also element composition of g-C3N4. The morphology variation results in largely increased SSA from 40.22 to 117.27m2g−1, obviously reduced pore size from 3.99 to 2.77nm for g-C3N4 and formation of in-plane holes. Moreover, composition variation of g-C3N4 has also been found to have changed as the pyrolysis time extended. These changes have significant impact on the optical properties and photoelectrical characters of g-C3N4, which were investigated by UV-DSR, PL and Photocurrent measurement. The photocatalytic activity of g-C3N4 obtained via 9h thermal treatment at 550°C has shown highest photocatalytic activity, which is 1.77 times than that of g-C3N4 obtained via 3h thermal treatment under visible irradiation and 1.99 times under UV irradiation respectively.