Electron–Hole Recombination Is Suppressed by Breaking the Ring Planarity in Porphyrin Nanorings: Density Functional Atomistic Simulation

The Journal of Physical Chemistry C, Год журнала: 2025, Номер unknown

Опубликована: Март 27, 2025

Porphyrin nanorings get enormous attention as potential photovoltaic materials due to their unique and tunable optoelectronic properties. Distribution of charge in porphyrin can alter the performance. We investigate photodynamics two nanorings, i.e., fused meso observe role delocalization on carrier relaxation dynamics. Employing nonadiabatic molecular dynamics within framework density functional tight binding theory, we demonstrate that nanoring exhibits six times longer exciton lifetime compared nanoring. Charges are more localized at band edge states reduce orbital overlap between electron hole wave functions. As a result, localization weakens coupling, resulting delayed electron–hole (e−h) recombination. Participation low-frequency electron-vibrational modes rapid decoherence energy gap further extends lifetime. Additional β conjunctions dimer facilitate throughout because fusions hold circular planarity Quick creates strong ground excited states, quick Further, simulated transition rate support our results. e−h recombination is dependent Our simulations give light effect by tuning geometry provide valuable guidance design high-performance organic conjugated system-based appliances.

Язык: Английский

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Hard–Soft Acid–Base Theory Explains Photoexcited Carrier Dynamics in Porphyrin/CNT Nanohybrids: Time-Domain Atomistic Analysis

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Июнь 5, 2025

We employ the fundamental chemical concepts of hard-soft acid-base to formulate general principles governing excited-state dynamics in zinc porphyrin (ZnP)/carbon nanotube (CNT) hybrids for energy photoconversion. Atomistic quantum simulations demonstrate that electron-withdrawing and donating substituents at ZnP β-pyrrolic position strongly influence dynamics. photoexcitation produces subpicosecond electron transfer (ET) from CNT, agreement with experiment. Substitutions CN by H tBu accelerate ET. The trend is directly related concept because soft-soft interaction between tBu-ZnP acid mild CNT base enhances donor-acceptor coupling. Longer coherence more active vibrational modes facilitate ET tBu-ZnP/CNT. Electron-hole recombination CN-ZnP/CNT occurs on a hundred picosecond time scale, nicely corroborated exciton lifetime extended beyond nanosecond substitutions. tBu-ZnP/CNT increases splitting highest occupied orbitals two subsystems, reduces their mixing, decreases nonadiabatic coupling ground excited states. Rapid decoherence involvement low-frequency vibrations favor longer lifetimes. Our investigation reveals larger pKa gives rapid slow provides detailed mechanistic information, essential future optoelectronic applications.

Язык: Английский

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Photocarrier Dynamics of Two-Dimensional Aza-Fused Covalent Organic Frameworks as Bifunctional Photocatalysts toward Overall Water Splitting

ACS Applied Materials & Interfaces, Год журнала: 2024, Номер 16(45), С. 62043 - 62051

Опубликована: Окт. 31, 2024

Designing high-efficiency bifunctional photocatalysts toward photoinduced overall water splitting is one of the most promising and challenging research directions for clean energy generation. By employing static electronic structure calculation nonadiabatic molecular dynamics (NAMD) simulation, we herein established a recently synthesized two-dimensional (2D) aza-fused covalent organic framework (aza-COF) as potential photocatalyst reactions. Our calculated results reveal that overpotentials hydrogen evolution reaction oxygen are only 0.06 0.31 V, respectively, at pH = 4. The photoexcited charge carriers studied through NAMD simulation predicts electron–hole recombination time (25.15 ns), this confirms photogenerated electron hole migrate to active sites occurrence before they recombine. Therefore, our suggest 2D aza-COFs exhibit great metal-free single-material under visible light.

Язык: Английский

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Controlling the Charge Carrier Dynamics of o-B₂N₂ Monolayer through Pnictogen Family Atoms Doping

The Journal of Physical Chemistry Letters, Год журнала: 2024, Номер 15(37), С. 9388 - 9396

Опубликована: Сен. 6, 2024

In the quest for an efficient solar energy harvester, one should focus on materials that have a large carrier lifetime. Using time-domain density functional theory combined with nonadiabatic molecular dynamics simulations, we herein established single-atom doping from pnictogen family can effectively alter electron-hole recombination time in o-B

Язык: Английский

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