Unusual Electronic Properties of Cellulose Nanocrystals Conjugated to Cobalt Phthalocyanine: Long-Lived Charge Separation and Visible-Light-Driven Photocatalytic Activity

• Author(s) / Creator(s)

  • Kazi M. Alam, Pawan Kumar, Narendra Chaulagain, Sheng Zeng, Ankur Goswami, John Garcia, Ehsan Vahidzadeh, Manish L. Bhaiyya, Guy M. Bernard, Sanket Goel, Vladimir K. Michaelis, Alexander E. Kobryn, Sergey Gusarov, and Karthik Shankar*

• Octacarboxylated cobalt phthalocyanine (CoPc) was covalently conjugated to cellulose nanocrystals (CNCs) by employing an esterification protocol. Solid-state NMR, X-ray photoelectron spectroscopy (XPS), Raman, and infrared spectra were used to verify and study the nature of covalent attachment responsible for the immobilization of CoPc on the CNC surface. The covalent attachment was investigated from a theoretical simulation perspective using dispersion-corrected density functional theory (DFT) calculations, which verified the stable bond formation between CNC and CoPc. CoPc is an organic semiconductor with a high exciton binding energy, and CNCs are known to be insulating. Yet, Kelvin probe force microscopy (KPFM) indicated charge carrier generation and long-lived charge separation in the CNC–CoPc conjugate compared to pristine CoPc under visible light illumination. Such behavior is more typical of a semiconductor nanocomposite. The CNC–CoPc conjugate exhibited superior performance in the visible-light-driven surface photocatalytic reduction of 4-nitrobenzenethiol (4-NBT) to p,p′-dimercaptoazobenzene (DMAB) and photodegradation of rhodamine B.

• Date created

  2022-09-15

• Subjects / Keywords

  • cellulose
  • nanocrystals
  • cobalt phthalocyanine
  • dye degradation
  • plasmon exciton coupling

• Type of Item

  Article (Published)

• DOI

  https://doi.org/10.7939/r3-fngd-7f82

• License

  Attribution-NonCommercial 4.0 International