ChemPhotoChem最新文献

This study reports the synthesis of γ-Al₂O₃ supported CuO (C-AlO14) material via impregnation technique. The synthesized C-AlO14 photocatalyst successfully degraded crystal violet (CV) dye via photoactivation of peroxymonosulfate (PMS). The synthesized photocatalysts are thoroughly examined using a variety of techniques, including energy dispersive X-ray spectroscopy, scanning electron microscopy, X-ray diffraction analysis, and fourier transform infrared spectroscopy. The Tauc plots indicated the band gap energy of C-AlO14 was 2.1 eV compared to 1.67 eV for CuO and 3.3 eV for γ-Al₂O. The results indicated that CV (10.0 mg L⁻¹) is almost entirely eliminated (99%) by using C-AlO14 (30 mg) in the presence of PMS (2.0 mM) at pH 6.8 under 30 min of UV irradiation. Scavenger studies indicate that the reaction system produces SO₄^•−, ^•OH, h⁺, and O₂^•−. Accordingly, detailed charge transfer pathway mechanism is explored for UV/C-AlO14/PMS system. Furthermore, degradation intermediates of CV are identified, and subsequently degradation pathways are proposed. Ecological structure activity relationships analysis indicated that UV/C-AlO14/PMS process degrades organic contaminants by environmentally safe route.

Multiresonant thermally activated delayed fluorescence (MR-TADF) materials have emerged as next-generation OLED emitters owing to their narrowband emission, high color purity, and potential for 100% exciton utilization. Among the various MR-TADF scaffolds, carbonyl/nitrogen-based, quinolino[3,2,1-de]acridine-5,9-dione (QAO) cores have attracted significant attention due to their modularity and electronic tunability. This review article presents a systematic analysis of recent advancements in QAO-based emitters, categorized into three molecular design strategies: core locking, core substitution, and core extension. Core locking enhances rigidity, minimizes vibrational loss, and narrows emission profiles critically mandated by blue-emitting MR-TADF systems. Substitution at key positions enables fine control over emission wavelength, ΔE_ST, and photoluminescence quantum yield (Φ_PL). Core extension via π-conjugation elongation or fused aromatic units leads to improved device efficiencies and diverse emission colors, including green and deep-blue electroluminescence. Collectively, these strategies have produced emitters with Φ_PL exceeding 90%, EQEs above 30%, and full-width half maximums as low as 20 nm. We conclude by highlighting current limitations, including RISC bottlenecks, doping concentration effects, and synthetic challenges, while proposing design pathways toward next-generation multifunctional, solution-processable, and chiral MR-TADF materials. This review article provides a roadmap for advancing carbonyl-nitrogen based MR-TADF emitters toward high-performance OLED technologies.

The development of photosensitizers (PSs) with extended triplet-state lifetimes, efficient reactive oxygen species (ROS) generation, organelle-specific targeting, good water solubility, and high photostability, is essential for advancing photodynamic therapy (PDT). Although molecular aggregation holds promise for designing organic nano-PSs with enhanced therapeutic effects, controlling dye aggregation remains a significant challenge. In this study, we present a simple yet robust synthetic strategy for developing heavy-atom-free PSs with intramolecular charge transfer (ICT)-coupled aggregation-induced emission (AIE) properties. These PSs feature donor–acceptor (D–A) structures, namely Lyso-Naphth-AIE and Butyl-Naphth-AIE, which exhibit high photostability and negligible dark toxicity. Upon light irradiation, these AIE systems efficiently generate ROS via both Type I and II mechanisms. By incorporating p-methoxytriphenylamine (MeO-TPA) as a rotor unit, we enhanced AIE and promoted twisted intramolecular charge transfer (TICT), resulting in improved near-infrared luminescence in the aggregated state. Notably, the Lyso-Naphth-AIE nano-PSs demonstrated effective lysosome-targeting and light-triggered intracellular ROS production, leading to apoptosis, in cancer cells. This work establishes a new approach for designing multifunctional AIE PSs that enable imaging-guided PDT.

It is known that peri-aryloxyquinones based on 5,12-naphthacenequinone (hereinafter referred to as PANQs) undergo multiple photoswitching between the initial state and thermally stable ana-quinone. However, no nuclear magnetic resonance (NMR) studies of their photochromic performance have been reported previously. In this work, a series of 11 new PANQs are prepared, and their light-induced reaction is investigated using NMR spectroscopy for the first time. The results support early observations regarding the fatigue resistance as well as thermal and chemical stability of the photoisomers of peri-aryloxyquinones based on naphthacenequinone.

The rational design of heterostructured photocatalysts integrating efficient charge separation and CO₂ enrichment remains a key challenge in artificial photosynthesis. Herein, a ZIF-8/TiO₂ heterojunction photocatalyst is reported, fabricated via gas-phase deposition and hydrothermal methods. The composite combines ZIF-8's high CO₂ adsorption capacity with TiO₂'s photocatalytic activity, forming a chemically bonded Type-II interfacial heterojunction that promotes directional charge separation and suppresses carrier recombination. Synergy between ZIF-8's porous CO₂ enriching framework and heterojunction-driven charge transfer enhances CO₂ photoreduction performance: under simulated sunlight, it achieves CH₄ and CO evolution rates of 1.30 and 4.22 μmol g⁻¹h⁻¹, respectively. This work provides a scalable paradigm for integrating CO₂ capture with semiconductor heterointerfaces in photocatalytic systems.

Perovskite solar cells (PSCs) have rapidly progressed over the past few years, with efficiencies approaching 27%. However, the formation of detrimental defects resulting from rapid crystallization that induce the nonradiative recombination and low carrier mobility hinders further commercialization development. The use of passivators to reduce the defects in perovskite materials has been demonstrated to be an effective approach for enhancing the photovoltaic performance and long-term stability of PSCs. Screening strategy of passivators have received increasing attention as the library of chemical passivators consistently expand. First, this concept discusses the main types of defect in perovskite materials and reviews their properties. We examine the deleterious impact of defects on device efficiency and highlight the passivation mechanism of Lewis base molecules. Second, this concept also provides an overview of passivator screening strategies, including donor–acceptor (D-A) pair regulatory strategies and engineering spatial conformation. Finally, we propose screening direction for future research, which, in our view, will be crucial for unlocking the full potential of PSCs using the concept of defect passivation.

Carbon nanodots (CNDs) have attracted growing interest due to their potential applications in sensing, imaging, and optically controlled bio-applications. Herein, the covalent functionalization of citric acid/ethylenediamine-based CNDs with a tetra-ortho-fluoro-azobenzene derivative (F-Azo) is presented. This approach aims to integrate the intrinsic photoluminescence of CNDs with the reversible photoisomerization properties of F-Azos triggered by visible light. The CND-F-Azo hybrids are synthesized via a terminal carboxylic acid group located on the F-Azo, which can be attached via amide coupling to surface-accessible amines on the CNDs. The structural and optical characterization of the resulting hybrid material is performed using a variety of analytical and spectroscopic techniques, as well as computational analyses supporting the covalent linking between the molecular and nanomaterial components and the interactions existing between them. In order to assess the impact of functionalization on physicochemical properties, the hybrid is further analyzed with respect to zeta potential, lipophilicity, and cell viability using HEK-293 cell assays. To assess cellular uptake and intracellular localization, confocal fluorescence imaging is employed. This work contributes to the development of light-responsive nanomaterials with tailored surface properties, highlighting the potential of Azo-functionalized CNDs as multifunctional platforms for future in vitro and in vivo optostimulation applications.

Switchable intersystem crossing (sISC) is a novel concept in the design of functional dyes that enables dynamic modulation of fluorescence and triplet state formation in response to changes in the dye's environment. Unlike conventional dyes, where intersystem crossing and fluorescence rates are entirely determined by molecular structure, sISC dyes allow reversible switching between these functions based on external factors, such as solvent polarity. sISC can arise from various photophysical mechanisms involving charge–transfer states, whose energies are sensitive to the surrounding environment. Mechanisms such as thermally activated delayed fluorescence and spin–orbit charge transfer intersystem crossing can be employed to design sISC dyes. The ability to fine-tune photophysical processes without chemical modification of the dye's structure opens new possibilities for biomedical applications, including bioimaging, photodynamic therapy, and optogenetic control. This paper introduces the concept of sISC, provides key examples of dyes exhibiting this behavior, and discusses approaches for their design.

Chiral copolymer thin films show a strong chiroptical response, in the present study with values for the circular dichroism (CD) reaching up to 16,000 mdeg and a dissymmetry parameter, g_abs, of up to 0.7. This behavior renders these films highly attractive for optoelectronic applications, such as OLEDs with intrinsic circularly polarized emission. Such films of the achiral copolymer poly-[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(benzo[2,1,3]thiadiazol-4,8-diyl)] (shortly, F8BT) blended with helicene-like chiral inducers are investigated. These films exhibit a unique sign inversion effect of the CD and the circularly polarized luminescence (CPL) signals as a function of film thickness (with a threshold of about 100 nm) and annealing temperature (with a threshold of about 150 °C). It is shown that structural reorganization of the chiral supramolecular phase is the most likely reason for this effect. Detailed measurements of the CPL spectra as a function of the detection angle underline the importance of detecting the emission at normal incidence to the polymer surface to avoid distortion of the CPL signal, which is otherwise identified by a bisignate CPL response at larger detection angles due to waveguide emission from the edge of the polymer film.

The long-lived radical R6G^•, derived from the cationic dye rhodamine 6G (R6G⁺) by reduction, is of growing interest in photoredox catalysis. This manuscript discusses three methods of its preparation in dimethylsulfoxide, highlighting spectral differences due to solvatochromism, co-solutes, and the basicity of the solution. Upon excitation, R6G^•* can release an electron to a substrate molecule or as a solvated electron, leading back to R6G⁺. However, a second reduction of R6G^• is not observed to be reversible here, decreasing the overall concentration of R6G^• and R6G⁺ with time. R6G⁺ can also be deprotonated to R6G1 under basic conditions, and even double deprotonation to R6G2⁻ is possible, though this may undergo irreversible reaction over time. Excitation of R6G1 leads to the formation of a photoproduct stable for seconds, which then reforms R6G1. If R6G^• is exposed to basic conditions in the presence of oxygen, it is oxidized to R6G⁺, which is then quickly deprotonated to yield R6G1 again. Hence, in basic solution, R6G1 is the predominant species, so that other light-induced reaction pathways than with R6G⁺ are accessible. It remains to be determined whether the photoproduct of R6G1 could be beneficial for a photocatalytic application under strongly basic conditions.