Arginine-Induced Self-Assembly of Protoporphyrin to Obtain Effective Photocatalysts in Aqueous Media Under Visible Light

Abstract

The fabrication of controlled supramolecular nanostructures via self-assembly of protoporphyrin IX (PPIX) was studied with enantiomerically pure l-arginine and d-arginine, and we have shown that stoichiometry controlled the morphology formed. The nanostructure morphology was mainly influenced by the delicate balance of π-π stacking interactions between PPIX cores, as well as H-bonding between the deprotonated acidic head group of PPIX with the guanidine head group of arginine. PPIX self-assembled with l-/d-arginine to create rose-like nanoflower structures for four equivalents of arginine that were 5–10 μm in length and 1–4 μm diameter. We employed UV-vis, fluorescence spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FT-IR) techniques to characterize the resulting self-assembled nanostructures. Furthermore, we investigated the catalytic activity of PPIX and arginine co-assembled materials. The fabricated PPIX–arginine nanostructure showed high enhancement of photocatalytic activity through degradation of rhodamine B (RhB) with a decrease in dye concentration of around 78–80% under simulated visible radiation.

A readily synthesized bismuth oxyiodide/attapulgite for the photodegradation of tetracycline under visible light irradiation

“…This means the e − generated from the BiOI reacts with the O 2 in H 2 O to develop the O 2 ˙−, and the generated h + participated in the oxidation of RhB. 55,56 The ˙OH radical could not be generated from the h + reacting with OH − or H 2 O. It could be attributed to the fact that the VB position of BiOI was not adequate to acquire the ˙OH.…”

Supramolecular Engineering and Self-Assembly Strategies in Photoredox Catalysis

“…65 Recently, a similar co-assembly between a carboxylic acid based porphyrin and enantiomerically pure L-/D-arginine has been used for studying the degradation of the pollutant, Rhodamine B. 66 In a rare recent report, hydrogen and oxygen evolution (40.8 and 36.1 μmol g −1 h −1 ) was achieved by a porphyrin supramolecular photocatalyst (TCPP), without the addition of any inorganic co-catalysts (Figure 10). 67 The oxidizing ability of the photocatalyst was evident from its efficient photodegradation activity, 10 times higher than that of g-C 3 N 4 .…”

“…The Fmoc- l -Lys nanofiber formed via H-bonding and π-stacking was post-conjugated with in situ generated DOPA melanin via a Schiff base reaction to produce quinone acceptors that mediate an efficient electron transfer from the photoexcited Sn–porphyrin J-aggregates and generate long-lived charge-separated species owing to the close proximity of all of the components in their aggregated state, in comparison to their free form . Recently, a similar co-assembly between a carboxylic acid based porphyrin and enantiomerically pure l -/ d -arginine has been used for studying the degradation of the pollutant, Rhodamine B …”

Effect of ethylene glycol and its derivatives on the aggregation properties of reactive Orange 13 dye aqueous solution

“…Moreover, it is obvious from the IR peaks that there is slightly shiing of peaks towards shorter wave number means down shi. 47 The reason for this is that on adding water and organic solvents to dye the formation of hydrogen bonding leads to decrease in bond strength between O and H groups of dye molecules.…”