Porous graphitic carbon nitride with high concentration of oxygen promotes photocatalytic H2 evolution

• Published in: RSC advances Vol. 12; no. 52; pp. 33688 - 33695
• Main Authors: Jia, Ruokun, Yu, Xueli, Yang, Xiaohang, Wang, Xinzhe, Yang, Jiaming, Huo, Xuyang, Qi, Qiuju
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 24-11-2022; The Royal Society of Chemistry
• Subjects: Carbon; Carbon nitride; Chemistry; Colloiding; Electron distribution; Hydrogen evolution; Hydrogen production; Oxygen; Oxygen content; Photocatalysis; Photocatalysts; Photoelectricity; Silicon dioxide
• ISSN: 2046-2069
• DOI: 10.1039/d2ra05662c

Porous structure design and the content regulation of heteroelements have been proved to be effective strategies to boost photocatalytic H2 generation activity of graphitic carbon nitride (g-C3N4) based photocatalyst. Herein, a series of porous graphitic carbon nitride with high concentration of oxygen (g-C3N4–O) photocatalysts were synthesized via in situ polymerization process using colloidal SiO2 as oxygen source. The content of oxygen within the g-C3N4–O photocatalysts could be tuned by adjusting the amount of added colloidal SiO2 during the preparation procedure. The introduced oxygen replaced two-coordinated nitrogen atom, influencing band edge position and localized electron distribution, thereby enhancing visible light harvesting and photoelectric conversion. As a result, the g-C3N4–O photocatalyst with an optimal oxygen content (8.39 wt%) showed 10.5 fold enhancement in H2 evolution rate compared to that of bulk g-C3N4, attributed to the porous structure and high concentration of incorporated oxygen.