Highly dispersed Pd nanoparticles hybridizing with 3D hollow-sphere g-C3N4 to construct 0D/3D composites for efficient photocatalytic hydrogen evolution

• Published in: Journal of catalysis 2019-10, Vol.378, p.331-340
• Main Authors: Huang, Ziwei, Zhang, Yiwei, Dai, Hengyi, Wang, Yanyun, Qin, Chaochao, Chen, Wenxia, Zhou, Yuming, Yuan, Shenhao
• Format: Article
• Language: English
• Subjects: 3D hollow sphere g-C3N4; Charge migration; Pd nanoparticles; Photocatalytic hydrogen evolution
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2019.09.007

[Display omitted] •The hollow-sphere g-C3N4 was used as a substrate material for uniformly dispersing Pd nanoparticles to expose more active sites.•The synergistic effect of the 3D g-C3N4 and Pd nanoparticles promoted efficient separation of photogenerated carriers.•According to TAS, it was estimated that the charge separated state lifetime of Pd/g-CN (10 h) was shortened to 1.4 ns ± 338.0 ps. Herein, 3D hollow-sphere structure graphitic carbon nitride (g-C3N4) with large specific surface area and high porosity is synthesized through a mild, heat polymerization, template-free route. The as-prepared hollow-sphere structure can be used as a substrate material for uniformly dispersing Pd nanoparticles to enhance the absorption of visible light and expose more active sites. Pd nanoparticles as electron acceptor are implanted into g-C3N4, which increases the trapping capability of capturing transition electrons to gain more photogenerated carriers participating in surface reactions. Therefore, the estimated charge separation lifetime of Pd/SCN (10 h) investigated by transient absorption spectroscopy was 1.4 ns ± 338.0 ps, which is only half of SCN. Benefiting from the unique structure and the excellent optical performance, the obtained Pd/SCN composites exhibited prominent photocatalytic hydrogen evolution performance under visible light irradiation. Especially, the photocatalytic hydrogen rate of Pd/SCN (10 h) reached 267.9 µmol/h, almost 10 times higher than the Pd/2D g-C3N4. Simultaneously, a possible mechanism for photocatalytic H2 reaction was proposed based on the characterization results.