K and halogen binary-doped graphitic carbon nitride (g-C3N4) toward enhanced visible light hydrogen evolution

• Published in: International journal of hydrogen energy Vol. 44; no. 51; pp. 27704 - 27712
• Main Authors: Zhu, Qiu-Hui, Chen, Zhou, Tang, Li-Na, Zhong, Yue, Zhao, Xiu-Feng, Zhang, Li-Zhong, Li, Jian-Hui
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 22.10.2019
• Subjects: Carbon nitride; K, F co-doping; Photocatalysis; Solar energy; Visible light; Visible light; K, F co-doping; Photocatalysis; Solar energy; Carbon nitride
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2019.09.013

Water splitting driven by solar energy to produce hydrogen, which is highly dependent on the designing of semiconductor photocatalyst, is an efficient technology to address energy shortage problems and environment issues simultaneously. Here, the halogen and potassium binary-doped graphitic carbon nitride (named as X-K-C3N4, X = F, Cl, Br, I) photocatalysts were synthetized via simply one pot thermal polymerization method, which shown optimized band structure, enhanced optical absorption, higher separation rate of photogenerated carriers, and thus improved photocatalytic performance under visible light irradiation. As result, F–K–C3N4 is demonstrated to be highly efficient in the separation and transfer of carriers owing to the existence of C–F bond, CN triple bond and K junction. The F–K–C3N4 shows a highest H2 evolution rate of 1039 μmol g−1 h−1 and a remarkable stability under visible light irradiation (λ ≥ 420 nm), which is about 8.5 times higher than that of pristine g-C3N4. •We systematically studied the effect of K and halogen binary-doped graphitic carbon nitride on photocatalytic performance.•The significantly enhanced photocatalytic activity is described to the double accelerations of F, K binary doping.•F–K–C3N4 exhibits improved visible light harvesting ability and photogenerated charge separation rate.•The F–K–C3N4 exhibits 8.5 times higher H2 generation rate than that of pristine C3N4.