Synthesis and Efficient Visible Light Photocatalytic Hydrogen Evolution of Polymeric g-C3N4 Coupled with CdS Quantum Dots

• Published in: Journal of physical chemistry. C Vol. 116; no. 25; pp. 13708 - 13714
• Main Authors: Ge, Lei, Zuo, Fan, Liu, Jikai, Ma, Quan, Wang, Chen, Sun, Dezheng, Bartels, Ludwig, Feng, Pingyun
• Format: Journal Article
• Language: English
• Published: Columbus, OH American Chemical Society 28.06.2012
• Subjects: Catalysis; Catalysts: preparations and properties; Chemistry; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; General and physical chemistry; General, apparatus; Materials science; Nanoscale materials and structures: fabrication and characterization; Other topics in nanoscale materials and structures; Physics; Quantum dots; Surface physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Quantum dot; Fourier transform spectroscopy; Chemical method; Photocatalysis; Charge carrier; Photoluminescence; Carbon; X ray diffraction; Composite material; Nitrides; Transmission electron microscopy; Platinum; Radiation effect; Charge carrier generation; Alcoholic solution; Aqueous solution; Catalyst activity; Nanostructured materials; Catalyst; X-ray photoelectron spectra
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp3041692

Novel CdS quantum dot (QD)-coupled graphitic carbon nitride (g-C3N4) photocatalysts were synthesized via a chemical impregnation method and characterized by X-ray diffraction, transmission electron microscopy, ultraviolet–visible diffuse reflection spectroscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and photoluminescence spectroscopy. The effect of CdS content on the rate of visible light photocatalytic hydrogen evolution was investigated for different CdS loadings using platinum as a cocatalyst in methanol aqueous solutions. The synergistic effect of g-C3N4 and CdS QDs leads to efficient separation of the photogenerated charge carriers and, consequently, enhances the visible light photocatalytic H2 production activity of the materials. The optimal CdS QD content is determined to be 30 wt %, and the corresponding H2 evolution rate was 17.27 μmol·h–1 under visible light irradiation, ∼9 times that of pure g-C3N4. A possible photocatalytic mechanism of the CdS/g-C3N4 composite is proposed and corroborated by photoluminescence spectroscopy and photoelectrochemical curves.