Incorporation of graphene oxide to metal‐free phthalocyanine through hydrogen bonding for optoelectronic applications: An experimental and computational study

Abstract

This paper focuses on incorporation of graphene oxide (GO) to metal‐free phthalocyanine (MPc) through only hydrogen bonding and π‐π stacking. Briefly, Pc‐GO composites at various concentrations were prepared by self‐assembly method. The processing time was kept below 10 min to avoid covalent attachment and we aimed at answering the research question of what will happen if the conjugation is realized only through hydrogen bonding under extremely limited processing times. The as‐prepared MPc‐GO composites were characterized by Fourier transform infrared (FT‐IR), UV‐Vis, scanning electron microscope (SEM), and fluorescence analysis. We report that the interaction between MPc and GO could immediately be initiated upon mixing of corresponding solutions. Also, complete conjugation by hydrogen bonding and π‐π stacking could be reached even only in 5 min of sonication time. In addition, it was also determined that the prepared MPc‐GO composites are stable at room conditions and during dilution. Finally, the optoelectronic properties of MPc and MPc‐GO composites were also investigated experimentally and theoretically. Both experimental and theoretical results suggest that MPc‐GO composites exhibit improved optoelectronic properties as compared to MPc, even though the conjugation of GO to MPc was only via hydrogen bonding without covalent attachment.

Graphene Oxide/Cholesterol-Substituted Zinc Phthalocyanine Composites with Enhanced Photodynamic Therapy Properties

“…Interestingly, while GO/Chol-ZnPc showed monomeric Q bands, Chol-ZnPc exhibited a doublet with absorbance maxima at about 703 nm (Q x ) and 724 nm (Q y ), suggesting aggregation of Chol-ZnPc in the solvent [67]. Upon introduction of GO, the doublet disappeared and turned into a single peak, an observation in good agreement with previous reports [37]. Further, this peak was blueshifted as compared to Q y .…”

“…However, the processing time was too limited in the present work for a covalent attachment. In addition, it could be realized that the functional groups in the present work cannot allow a hydrogen bonding, unlike the previous work of Yabas et al [37]. In fact, both the red shift and the blue shift of the Q band were reported as depending on the substituted groups in previous works where various GO and Pc derivatives were coupled at relatively similar processing conditions [42,74,75], and the blue shift of the Q y in the present work might be ascribed to π−π and electrostatic interactions between GO and Chol-ZnPc.…”

“…Apart from this, it is known that the composites of Pc with low-dimensional carbon materials could enhance the charge transfer properties through π-π stacking. Particularly, graphene oxide (GO) is receiving considerable interest as a constituent material in such composite structures due to its oxygen-containing functional groups and high photothermal conversion efficiency [37][38][39][40][41]. In this context, various GO/Pc composites have been investigated for PDT, combined photothermal/PDT, combined sonodynamic/PDT, combined drug delivery/PDT, and image-guided photothermal/PDT applications, with promising results [41][42][43][44][45][46][47][48].…”

Density functional theory for exploration of chemical reactivity: Successes and limitations

“…Saloni et al 25 reported lead-free perovskites A2BCl6 for photovoltaic applications by using DFT approach. Yabas et al 26 studied optical and electronic properties of MPc and MPc-Go composites with the help of DFT and experimental approaches. Poon et al 27 performed DFT calculations for ionomers consisting of amidinium or imidazolinium groups.…”