Journal of Photochemistry and Photobiology A-chemistry最新文献

The pivotal role of non-covalent interactions has been increasingly acknowledged by researchers in the intricate design and advancement of non-fused ring electron acceptors (NFREAs). This surge in attention arises from their profound influence on the facilely twisted molecular geometries and critical photoelectric attributes inherent to organic solar cells (OSCs). In this study, various selenium atoms and alkoxy groups were strategically introduced into the well-performing NFREA A4T-16, leading to the creation of molecules denoted as Se-1 to Se-9 and O1 to O9. Utilizing density functional theory (DFT) and time-dependent density functional theory (TD-DFT), a comprehensive analysis of these molecules was conducted, encompassing factors such as intramolecular non-covalent interactions, the fill factor (FF), and the open-circuit voltage (V_OC). The electronic structures and photovoltaic characteristics of these molecules underwent a thorough investigation to elucidate the intricate mechanisms governing non-covalent interactions within NFREAs, thereby clarifying their functional significance. The findings disclose that acceptor molecules featuring selenium substitution display notably augmented Se∙∙∙O and S∙∙∙O non-covalent interactions, exceeding the strength observed in their alkoxy-substituted derivatives. This results in the selenium-substituted derivatives boasting superior overall planarity, narrower energy gaps, reduced excitation energies, and broader absorption bandwidths, thereby enhancing their charge transfer characteristics compared to A4T-16. Conversely, the alkoxy-substituted acceptor molecules display higher fill factor (FF) and superior open-circuit voltage (V_OC) relative to the selenium-substituted derivatives. Notably, the innermost substitutions at O6, O7, and O9 show the most promising outcomes, potentially indicating optimal power conversion efficiency (PCE).

CQDs@MOF-808 guest@host nanocomposite as a biocompatible photocatalyst has been synthesized using a ship-bottle approach involving the impregnation method for immobilization of glucose molecules as carbon quantum dots (CQDs) precursor into the MOF-808 pores to form Glucose@MOF-808 and further fabrication of carbon quantum dots (CQDs) via in-situ thermolysis route of glucose molecules loaded into the pores of MOF-808. The photocatalytic degradation efficiency of 86.62 % was calculated for CQDs@MOF-808 nanocomposite for degradation of Acid Blue 41 in 120 min under visible light irradiation, that was attributed to the presence of CQDs inside MOF-808 pores. The exceptional characteristics of CQDs include outstanding up-converted photoluminescence (UCPL) effects, photo-induced electron transfer, electron reservoir properties, and electron-hole separations, all contributing to the photocatalytic degradation of Acid Blue 41. The synthesized samples were characterized by PXRD, FT-IR, EDX, N₂ adsorption–desorption isotherm, TEM, DRS, PL, EIS and Mott − Sckottky measurements.

In this work, a simple and versatile chemosensor receptor TZPYZ was synthesized through the combination of thiazole with pyrazine-2-carbohydrazide, resulting in a confirmed chemical structure via various analytical techniques including FT-IR, ¹H, and ¹³C Nuclear Magnetic Resonance Spectroscopy, as well as High-Resolution Mass Spectroscopy analysis. TZPYZ exhibits specific colorimetric and photoluminescent responses to Ag⁺ ions in a solvent solution consisting of DMSO and H₂O (7:3, v/v). Upon addition of Ag⁺ ions, noticeable changes in absorption spectra occur, resulting in a visible color change from pale yellow to blue. Additionally, an enhanced emission intensity with wavelength at 523 nm, when excited at 410 nm. Notably, TZPYZ demonstrated exceptional selectivity for Ag⁺ ions over other metal cations, achieving a detection limit (LOD) of 10.6 × 10⁻⁹ M and 6.74 × 10⁻⁹ M and using the UV–visible & photoluminescent titration method. Interference studies indicated minimal disruption from other metal ions on emission at 523 nm, highlighting TZPYZ discerning capability for Ag⁺ ions. With a binding affinity of 3.622 × 10⁻¹¹ M⁻¹, TZPYZ proved effective in detecting Ag⁺ ions across various water samples, showcasing its practical utility. The mechanism of interaction between TZPYZ and Ag⁺ ions was investigated using various experimental techniques, including Job’s plot, Benesi-Hildebrand investigations, ¹H NMR, and HRMS analysis. Test strips coated with TZPYZ showed selective detection of Ag⁺ ions, indicating its potential for on-site applications. Furthermore, DFT computations provided insights into the structural and electronic properties of TZPYZ and its complex with Ag⁺ ions, further elucidating the binding mechanism and stability of the complex. In addition, TZPYZ demonstrated compatibility with biological systems, as fluorescence imaging tests on MCF-7 breast cancer cells confirmed both its non-cytotoxic nature and its proficiency in detecting intracellular silver ions. Based on these findings, TZPYZ is highlighted as a highly sensitive and selective chemosensor for Ag⁺ ions, with promising applications in environmental analysis and bioimaging.

Ketoprofen KET and other non-steroidal anti-inflammatory drugs NSAIDs are extensively used throughout the world to reduce pain, fever, and inflammation. As a result of this, they have been detected in environmental waters and represent a potential health risk. There are several reports about KET photocatalytic degradation but most of them deal with experimental conditions or catalytic materials to perform this process. In this study, the mechanisms and intermediates involved in KET photocatalysis with TiO₂ in aqueous media were investigated. First, the mineralization rate was assessed by TOC measurements. The formation and eventual degradation of intermediate organic compounds were investigated by HPLC, UV–Vis, IR, ¹H NMR and HPLC-MS studies. TOC analysis indicate that KET is quickly transformed into other compounds that eventually are degradated and 70 % mineralization was achieved after five hours of irradiation. UV–Vis and HPLC studies indicate that KET is transformed into some other aromatic compounds within minutes. IR studies demonstrate the conversion of KET into several aromatic compounds which in turn degradate into low molecular saturated and unsaturated acids. ¹H NMR studies indicate KET is transformed into several aromatic compounds such as 3-hydroxy-benzophenone, phenol, 1,4-hydroquinone, 1,2,4-benzenetriol, and catechol. HPLC-MS studies indicate KET is degradated by several photochemical and photocatalytic parallel mechanisms. Based on this and previous studies, a unified and complete mechanism for KET photocatalytic degradation is presented.

Sustainable and environmental benign technologies for inactivation of pathogenic marine bacteria in ballast water remains a challenge. Herein, graphitic carbon nitride (g-C₃N₄) loaded with FeOOH quantum dots (QDs) were fabricated and a synergistic photocatalysis-Fenton system was established, which inactivated Vibrio alginolyticus (7 log) in ballast water within 30 min under visible light irradiation. The bacterial inactivation rate constant in the coupling system was 26.5 and 6.6 times higher than traditional photocatalysis and Fenton system, respectively, exhibiting 88.8 % of synergistic coupling coefficient. The bactericidal efficiency remained consistent across varying pH levels, allowing direct application of this method in alkaline marine conditions. Free radicals including OH and O₂⁻ were proved to be the predominant contributors in the coupling system. The loading of FeOOH QDs could upshift conduction band potential of g-C₃N₄, thus photogenerated electrons were more easily trapped by O₂ to enhance the separation of charge carriers. The photogenerated electrons also accelerated the faster circulation of Fe(III)/Fe(II), which further inhibited electron-hole recombination. Furthermore, bacterial inactivation mechanisms were elucidated by examining total protein changes, intracellular ROSs level and enzyme activities. This work offers innovative approaches for marine bacterial inactivation and ballast water disinfection, which can also find applications in other environmental-related fields.

The extensive use of pesticides in modern agriculture has raised concerns about environmental contamination and adverse human health effects. Therefore, developing highly sensitive detection methods to identify pesticide residues is crucial for food safety and ecosystem protection. In this study, the Fe₂AlB₂ MAX phase was synthesized and characterized. After evaluating its peroxidase-mimetic performance using a colorimetric method, a new, sensitive, and simple dual fluorescence-colorimetric sensor was developed for the quantification of two common pesticides, acetamiprid (ACP) and imidacloprid (IMP), using fluorescein (FL). The developed method is based on the inhibitory impact of ACP and IMP on the enzymatic performance of the Fe₂AlB₂ MAX phase, specifically the inhibition of hydroxyl radical (OH) generation, which enhances the absorption and emission intensities of FL. The results confirmed that OH generated through the breakdown of H₂O₂ via the catalytic activity of the MAX phase can decrease the intrinsic absorption and emission intensities of FL. However, ACP and IMP inhibit the peroxidase-like activity of the MAX phase, leading to increased absorption and emission intensities of FL. The limit of detection values calculated for spectrophotometric and spectrofluorimetric quantifications were 2.8 μM and 0.051 μM for ACP and 1.72 μM and 0.013 μM for IMP, respectively. Furthermore, the proposed method was successfully utilized to accurately and reliably determine ACP and IMP in spiked real samples with satisfactory accuracy and precision. These developed methods offer several advantages, making them promising candidates for the direct, rapid screening of pesticide residues.

A novel D–π–A type of dye (BIM33) comprising diphenylamine as electron donor, diphenylacridine as a π-bridge and cyanoacrylic acid as an anchoring unit has been synthesized and used as sensitizer and co-sensitizer in dye-sensitized solar cells (DSSCs). The DSSC based on BIM33 achieved a power conversion efficiency (PCE) of 3.19 % under one sun (AM 1.5G). To improve the photovoltaic performance of the DSSCs, this orange dye was also co-sensitized with red benzothiadiazole (C1) and purple indoline (D205) organic dyes. The DSSCs based on co-sensitizers BIM33/D205 and BIM33/C1 showed superior PCEs of 6.57 % (J_SC  =  13.69 mA cm⁻², V_OC = 0.766 V, and FF = 0.63) and 6.82 % (J_SC = 14.47 mA cm⁻², V_OC = 0.722 V, and FF = 0.65), respectively, exhibiting significant improvements of 28 % and 36 % compared to the DSSCs based on D205 and C1, respectively. The high photovoltaic performance of the co-sensitized DSSCs may be explained by the broader visible light absorption and a denser packing of the dyes on the TiO₂ surface.

Ethanol solutions of functional hyperbranched polyorganosiloxanes (0.2 vol%) with a molar ratio of NH₂(CH₂)₂NH-/H[AuCl₄]x3H₂O of 8/1 were used as precursors for nanocomposite preparation using UV photolysis and X-ray radiolysis. It was shown that various irradiation modes provide the synthesis of gold nanoparticles (AuNPs) with tunable sizes and narrow size distributions. It was established that size distributions of AuNPs depend on the excitation wavelength. AuNPs with an average size of 3.5 nm were obtained by the direct excitation of gold ions using UV light with λ_max = 365 nm. Meanwhile, the action of a higher energy light (λ = 254 nm) on the metal polymer complexes resulted in formation of ultra-small nanoparticles with an average size of 1.5 nm, presumably due to the increased efficiency of their nucleation process. In the case of radiolysis with X-rays, reduction of Au³⁺ ions occurs due to reactions with radicals produced from ethanol and leads to the formation of AuNPs of 2–3 nm. Thus, the size distribution of the prepared AuNPs may be controlled by the irradiation mode, which critically affects nanomaterial properties. Additionally nanoparticles obtained by photochemical or radiation-chemical methods are free of chemical impurities, which is important for the development of functional materials.

The incorporation of noble metals onto TiO₂ nanostructure is considered as a promoting method to enhance the photocatalytic degradation of pollutant in air treatment process. In this study, highly organized TiO₂ nanotubes (NTs) were grown by the anodization method of Titanium substrates. The TiO₂-NTs were successfully decorated by platinum (Pt) nanoparticles (NPs) using two different deposition methods: (1) electrodeposition and (2) photodeposition.

We explore the impact of different deposition methods on the morphology of Pt nanoparticles (NPs) dispersed onto TiO₂ nanotubes and the optical characteristics of Pt-TiO₂ nanocomposites, investigating their efficacy in photocatalytic degradation We investigate the effect of varying the deposition method on the morphology of Pt-NPs dispersed onto TiO₂ nanotubes and the optical properties of the Pt-TiO₂ nanocomposites and their efficient photocatalytic activity degradation against Volatile Organic Compounds (VOCs) and bacteria. Scanning and Transmission Electron Microscopy (SEM and TEM) reveal a nanotubular TiO₂ anatase structure adorned with Pt NPs, with the quantity and size of NPs contingent upon the deposition technique employed. The photoluminescence (PL) spectra demonstrate that the Pt/TiO₂ heterojunction facilitates the separation of photogenerated charges, thereby diminishing carrier recombination rates. To point out the effect of Pt NPS, both pure TiO₂ and Pt/TiO₂ heterojunction were tested in the photodegradation of Ethyl Acetate (EA). The Pt/TiO₂ heterojunction exhibits superior photocatalytic performance compared to TiO₂ in EA degradation, regardless of the Pt deposition method employed. Optimal results are achieved with 120 s of Pt electrodeposition and 3 h of Pt photodeposition under visible irradiation, yielding kinetic constants of approximately 0.245 and 0.195 mg.m⁻³.s⁻¹, respectively, underscoring the pivotal role of the platinum deposition method in pollutant photodegradation. Respectively simultaneous removal of EA and bacteria (Escherichia coli) was tested using Pt and non-Pt decorated TiO₂ NTs. We attributed a total degradation of the bacteria after 180 min using the two efficient photocatalysts Electro 120 s and Photo 3 h compared to 60 % of degradation using pure TiO₂ nanotubes.

The present work demonstrates the ground and excited state aggregation behavior of two pyrene-based push–pull systems (Pyr-MC and Pyr-PyA) both in solid and solution state. The UV–Vis spectra of these molecules show a unique broaden spectral pattern at lower energy region (400–600 nm) in both H₂O and solid state. Further, along with the local (intense) emission band, a new (less intense) band is appeared at higher wavelength region (∼550 nm) in water, which is due to the formation of aggregates. Interestingly, it is the lowest energy emission out of all previously reported emission by pyrene derivatives. The experimental results suggest the formation of J-type aggregation in solid and solution. The average lifetime of these molecules is also measured in different solvents. Intriguingly, the ground/excited state J-type aggregation in solid and solution are similar in nature in spite of different mode of intermolecular interactions, and are supported by experimental results. The dipolar state plays an important role on the J-type aggregation process. The QTAIM (quantum theory of atom in molecule) theoretical framework is applied to analyze and understand the properties of molecules in terms of the distribution of electrons and the topological features of the electron density within a molecule. Importantly, bond paths provide information about the nature of chemical bonds, including their strength and directionality.