Amphiphilic Zinc Porphyrin Single‐Walled Carbon Nanotube Hybrids: Efficient Formation and Excited State Charge Transfer Studies

Abstract

Herein, the microscopic and spectroscopic characterization of a novel non‐covalent electron donor−acceptor system, in which three different metalloporphyrins (1, 2, and 3) play the dual role of light harvester and electron donor with SWCNTs as electron acceptor, is described. To this end, microscopy, that is, atomic force microscopy (AFM) and transmission electron microscopy (TEM) corroborate the formation of 1‐SWCNT, 2‐SWCNT, and 3‐SWCNT. Spectroscopy by means of Raman, fluorescence, and transient absorption spectroscopy confirmed efficient charge‐transfer interaction from photoexcited metalloporphyrins to SWCNTs in the ground and excited state of 1‐SWCNT, 2‐SWCNT, and 3‐SWCNT. The complementary use of spectroelectrochemical and transient absorption measurements substantiates the formation of one‐electron oxidized metalloporphyrins after photoexcitation. Multiwavelength global analysis provides insights into the charge‐separation and recombination processes in 1‐SWCNT, 2‐SWCNT, and 3‐SWCNT upon photoexcitation. Notably, both the charge‐separation and recombination dynamics are fastest in 2‐SWCNT. Importantly, the strongest interactions in the steady‐state experiments are associated with the fastest excited state decay in the time‐resolved measurements.

Strong near-infrared and ultrafast femtosecond nonlinearities of a covalently-linked triply-fused porphyrin dimer-SWCNT nanohybrid

“…Porphyrin functionalized nanocarbon materials (PFNM) play important roles in and significantly boost the development of many advanced photonic devices (e.g. photosynthesis, photovoltaic, photocatalysis, photosensitizers, photodynamic therapy, and optical limiters) attributed to the synergistic effect of both components and efficient photo-induced intrahybrid electron/energy transfer (ET/EnT) [1][2][3][4][5][6][7][8][9]. Among all porphyrin derivatives, porphyrin monomers functionalized nanocarbon materials (PMFNC) are widely used as optical limiters due to their easily-modulated photophysical properties, strong electron-donating ability, and larger excited state absorption cross section [10][11][12][13].…”

Multimodular Wide-Band Capturing Nanohybrids: Role of Carbon Nanotubes in Slowing Charge Recombination in Supramolecular C60-BisstyrylBODIPY-(Zinc Porphyrin)2 Donor–Acceptor Molecular Cleft

“…Diameter-sorted single-wall carbon nanotubes (SWCNTs) reveal good optical coverage in the visible–near-infrared (NIR) region and emit in the NIR region. , Hence, among other applications, they have been utilized in building donor–acceptor hybrids and further employing these hybrids in building light energy conversion devices. − In the “simple” donor–acceptor construction, photosensitizers (P) are either covalently or noncovalently attached to the SWCNTs to yield p-SWCNT hybrids. Depending upon the relative energy levels of P and SWCNT, the excitation of P could promote an electron from the LUMO level to the conduction band of the SWCNT.…”

A Carbon Nanotube Binding BODIPY‐C60 Nano Tweezer: Charge Stabilization through Sequential Electron Transfer

“…[13] Studies performed to date by us and others on sensitizer-SWCNTs have shown that both covalently modified or selfassembled (metal-ligand coordination, π-stacking, cationanion and ion-dipole interactions, polymer or DNA wrapping) indeed undergo electron transfer reactions. [1][2][3][4][5][6][7][10][11][12][13][14][15][16][17][18][19][20][21] Unfortunately, in the majority of the cases, the charge recombination processes occur at picosecond time scales due to the close proximity of the sensitizer to the SWCNT surface, making them less useful for photocatalytic and energy harvesting device building applications. This drawback demanded an altogether different strategy of designing donor-acceptor nanohybrids for charge stabilization.…”