Photoelectrochemical Studies on Metal-Doped Graphitic Carbon Nitride Nanostructures under Visible-Light Illumination

Catalysts

Dongseob Kim¹  N. Jayashree²  V. Manjunath³  Jaesool Shim⁴  I.Neelakanta Reddy⁴ 

[1] Aircraft System Technology Group, Korea Institute of Industrial Technology (KITECH), Cheonan 38822, Korea;Department of Civil Engineering, National Institute of Technology, Mangalore 575025, India;Department of Physics, Sri Padmavati Mahila Visvavidyalayam, Tirupati 517502, India;School of Mechanical Engineering, Yeungnam University, Gyeongsan 712749, Korea;

关键词: graphitic carbon nitride;    kinetics;    nickel;    electrochemical impedance spectroscopy;    photoelectrodes;    photoelectrochemical activity;   

DOI  :  10.3390/catal10090983

来源: DOAJ

【 摘 要 】

Recently, the engineering of optical bandgaps and morphological properties of graphitic carbon nitride (g-C₃N₄) has attracted significant research attention for photoelectrodes and environmental remediation owing to its low-cost synthesis, availability of raw materials, and thermal physical–chemical stability. However, the photoelectrochemical activity of g-C₃N₄-based photoelectrodes is considerably poor due to their high electron–hole recombination rate, poor conductivity, low quantum efficiency, and active catalytic sites. Synthesized Ni metal-doped g-C₃N₄ nanostructures can improve the light absorption property and considerably increase the electron–hole separation and charge transfer kinetics, thereby initiating exceptionally enhanced photoelectrochemical activity under visible-light irradiation. In the present study, Ni dopant material was found to evince a significant effect on the structural, morphological, and optical properties of g-C₃N₄ nanostructures. The optical bandgap of the synthesized photoelectrodes was varied from 2.53 to 2.18 eV with increasing Ni dopant concentration. The optimized 0.4 mol% Ni-doped g-C₃N₄ photoelectrode showed a noticeably improved six-fold photocurrent density compared to pure g-C₃N₄. The significant improvement in photoanode performance is attributable to the synergistic effects of enriched light absorption, enhanced charge transfer kinetics, photoelectrode/aqueous electrolyte interface, and additional active catalytic sites for photoelectrochemical activity.

【 授权许可】

Unknown