Journal of Photochemistry and Photobiology A-chemistry最新文献

The incorporation of quinacridone derivatives into the core of triphenylamine-based materials has a notable effect on their photovoltaic characteristics. By altering the electrical structure and optical characteristics, quinacridone derivatives substantially improve the photovoltaic performance of triphenylamine-based materials. By optimizing energy levels, improving charge transfer processes, and raising electron density at the acceptor end, the implementation of quinacridone derivatives improves photovoltaic performance. The utilization of theoretical probes offers valuable insights into optimizing photovoltaic qualities. Lower the HOMO-LUMO band gap better will be power conversion efficiency (PCE) and photovoltaic properties. Quinacridone derivatives are useful in improving the photovoltaic performance of materials based on triphenylamines, both through theoretical and experimental research. CAM-B3LYP/6-31G (d,p) in dichloromethane solvent yields satisfactory results for more investigation. A new hole-carrying system utilizing D-π-D and bis(4-methoxyphenyl)amino)phenyl as the donor unit is constructed. New compounds with quinacridone as a π-spacer were created. Eight novel molecules are built from (Q₁-Q₈) by altering the π-spacers. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) is used to calculate geometric parameters such as excitation energy, binding energy (E_b), transition density matrix (TDM), frontier molecular orbitals (FMO), reorganizational energy for hole-transport, density of states, and absorption maxima. V_oc for the D-π-D polymer system is investigated for the Q₁-Q₈:PC61BM complex. The research aims to create a material with superior hole transport capabilities that is also readily synthesized.

Different heteroatoms introduced to carbon dots (CDs) have been used extensively owing to their excellent optical properties, simple synthesis method, and multifunctional applications such as environmental detection, multicolor cell imaging, and gene therapy/delivery. Nitrogen and sulfur codoped carbon dots (PSNCDs) were prepared using persimmon fruit (Diospyros kaki) peel biomass waste and sodium thiosulphate by the straight route, showing excellent optical properties. The resulting PSNCDs exhibit consistent fluorescence emission at 440 nm under excitation at 360 nm, with a high quantum yield (approximately 16 %), making them suitable for a range of applications, including bioimaging, drug delivery, sensing, catalysts, and so on. The as-synthesized PSNCDs were subjected to various analytical methods to confirm their morphology and surface functionalization. High-resolution transmission electron microscopy displayed that the PSNCDs are predominately 2–4 nm with an average size of around 3 nm. Fourier-transform infrared and X-ray photoelectron spectroscopy analysis confirmed the amine and sulfur functional moieties on the outer surfaces and edges of the PSNCDs. The uniform particle size distribution and structural morphology were confirmed by transmission electron microscopy analysis. The Raman and X-ray diffraction investigation reveals that the as-synthesized PSNCDs appeared to be defective graphite-like structures with an intensity ratio of D to G is 0.65. Furthermore, PSNCDs were also utilized as fluorescent probes for cellular imaging. PSNCDs exhibited enhanced biocompatibility (cell viability 98 %) with regular fibroblast cells; in both in vitro and in vivo scenarios, they exhibited robust fluorescence signals upon fluorescent imaging of cultured fibroblast cells. These characteristics collectively validate the potential of PSNCDs for cell imaging without the need for supplementary modifications.

Herein, a cationic iridium(III) complex [(ppy)₂Ir(IPP)]PF₆ (ppy: 2-phenylpyridine; IPP: 2-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)phenol) was synthesized. Under the excitation of 328 nm (λ_ex = 328 nm) UV light, this complex emitted bright yellow orange light (500 ∼ 700 nm, λ_em,max = 582 nm), the Stokes shift was up to 254 nm, mainly due to excited-state intramolecular proton transfer (ESIPT) occurring in its ancillary ligand IPP. [(ppy)₂Ir(IPP)]PF₆ was very sensitive to Ni²⁺, which was caused by the ESIPT being hindered by the coordination of [(ppy)₂Ir(IPP)]PF₆ with Ni²⁺. Its bright yellow orange light disappeared within 1 min when Ni²⁺ (1.0 equiv.) was added in its solution (in DMSO/H₂O, v/v = 999/1), therefore, it can be used for “turn-off” chemiluminescent detection of Ni²⁺. The recognition of [(ppy)₂Ir(IPP)]PF₆ to Ni²⁺ was not interfered by many common metal ions (such as Na⁺, K⁺, Li⁺, Mg²⁺, Al³⁺, Ca²⁺, Fe³⁺, Ag⁺, Zn²⁺, Hg²⁺, Co²⁺, Pb²⁺, Mn²⁺, Ba²⁺ or Cr³⁺), however, Cu²⁺ was an interfering metal ion, but its interference can be completely masked by thiourea. The detection limit was as low as 3.31 × 10⁻⁷ mol∙L^-1 (0.331 μM). The Job’s plot analysis revealed that the stoichiometry of [(ppy)₂Ir(IPP)]PF₆ with Ni²⁺ was 1:1, its detecting mechanism based on ESIPT effect was demonstrated by ¹H NMR spectra and density functional theory (DFT) calculation.

Nitrogen-doped biomass carbon dots (MP-NCDs) based on mangosteen peel were prepared by one-step hydrothermal method. Transmission electron microscopy demonstrated that MP-NCDs were spherical and their particle size ranged from 2.6 to 5.0 nm. X-ray photoelectron spectroscopy indicated that they were composed of C, N, and O elements. Fourier transform infrared revealed that their surface was equipped with oxygen-containing and amino-containing groups. Bright blue light emission characteristics were demonstrated. They had high light stability in aqueous solution and salt solution. Furthermore, MP-NCDs could be utilized as a bifunctional fluorescent probe for detecting Cr₂O₇²⁻ and vanillin through the fluorescence quenching method, which exhibited high selectivity, sensitivity, and anti-interference performance. The detection limits of vanillin and Cr₂O₇²⁻ by MP-NCDs were determined to be 2.33 μM and 4.6 μM, respectively. A detailed analysis was conducted on the fluorescence quenching mechanism. The performance of the sensing system was tested in real samples using river water and infant formula as models.

Utilizing photocatalysis to degrade antibiotics in wastewater is a vital strategy. Here, a Z-scheme heterojunction was synthesized, consisting of defect-rich porous g-C₃N₄ and MoO₃, which exhibits remarkable photocatalytic degradation of tetracycline (TC). The results revealed that the optimal heterojunction sample exhibited a 2.47-fold enhancement of degradation efficiency compared with porous g-C₃N_4-x. Characterization analysis shows that the significant enhancement is attributed to the synergistic effects arising from the Z-scheme heterostructure and the introduction of nitrogen (N) defects, which collectively enhance the charge separation and light absorption capabilities of the material. Electron paramagnetic resonance (EPR) spectroscopy and free radical quenching experiments indicate that the vital degradation mechanism is the assault of •O₂^– and •OH on tetracycline. Additionally, the LC-MS studies demonstrated possible intermediates and degradation pathway of TC. The toxicity simulation analysis revealed that the heterojunction sample effectively mitigated the toxicity of tetracycline solution. This catalyst exhibits promising potential for applications in the elimination of antibiotics from aquatic environments.

The rate coefficient for the gas-phase reaction of acetic anhydride (Ac₂O) with chlorine atoms at 298 K and atmospheric pressure was experimentally determined (k_Ac2O+Cl = (1.3 ± 0.4) × 10^-12 cm³ molec⁻¹ s⁻¹), while the rate coefficient for the reaction with the hydroxyl radical was estimated (k_Ac2O+OH=1.9 x 10^-13 cm³ molec⁻¹ s⁻¹). For the Structure-Activity Relationship method, a value of 0.02 was determined for the −C(O)OC(O) group. The mechanism of photo-oxidation of acetic anhydride initiated by chlorine atoms was determined and CO, CO₂, CH₃C(O)OH (32 %), CH₃C(O)OC(O)C(O)H, and 3-hydroxy-1,4-dioxane-2,6-dione (20 %) were identified as products by infrared spectroscopy. Here we determined for the first time the relative energies of the primary reaction pathways for the CH₃C(O)OC(O)CH₂O· radical using computational methods, which confirmed our experimental data. Finally, the environmental implications of acetic anhydride emissions were calculated, showing an atmospheric lifetime between 31 and 220 days for the reaction with atmospheric radicals, while its wet deposition lifetime is 1.5 years.

In this study, a novel photocatalyst, 4-OMe-2,3,5,6-tetrafluorophenyl acetylide copper (TFPACu), was synthesized by introducing more electron-withdrawing groups (−F) onto the benzene ring of PhC₂Cu. The physicochemical properties of TFPACu were investigated using a variety of characterization techniques. The result of Mott-Schottky test suggested that TFPACu is an n-type semiconductor. The active species involved in the photocatalytic degradation process were investigated by electron spin resonance (ESR). The results indicate that OH and h⁺ was the main active species in the photodegradation process. Under natural solar light irradiation, the degradation rate of TC reached 96 % within 30 min. This work will offer a viable idea for the rational design and development of efficient and cost-effective photocatalysts.

Alzheimer’s disease (AD) represents the most widespread form of age-related cognitive degeneration, characterized by long-term degenerative damage, cognitive dysfunction, and profound deficits in logical thinking, knowledge acquisition, and interpersonal communication. A principal biomarker of AD involves the emergence and aggregation of β-amyloid (Aβ). Cranad derivatives are fluorescent probes capable of detecting, quantifying, and imaging Aβ aggregates. In this work, the effect of solvent and microheterogeneous environments on the photophysical behavior of CRANAD-2 and CRANAD-58 was investigated employing a large solvent set and several microorganized systems. Both the absorption and fluorescence spectra exhibit a substantial solvatochromic effect, resulting in significant Stokes shifts. Application of linear solvation energy relationships to correlate the fluorescence spectra maxima and the Stokes shift with microscopic solvent parameters suggests significant intramolecular charge transfer during the excitation, as corroborated by the increased dipole moment in the excited state. Generally, fluorescence quantum yields determined for CRANAD-2 exceed those of CRANAD-58 in most solvents, with low values in polar solvents and bigger values in non-polar solvents. Introduction of CRANAD-2 and CRANAD-58 into micellar and vesicular solutions notably augments the fluorescence emission intensity, accompanied by a blue shift in the fluorescence maxima. The fluorescence maxima values observed within microheterogeneous systems closely parallel those reported for interactions between CRANAD derivatives and soluble or aggregated Aβ amyloids which potentially constrains the efficacy of “in vivo” Aβ detection trials, because localization of CRANAD derivatives in non-polar microenvironments present in biological media could interfere with the detection of amyloid fibers.

Valorizing biomass waste through photoelectrochemical (PEC) methodology provides an attractive strategy for generating H₂ and value-added chemicals by enabling a carbon–neutral cycle. Herein, we present an investigation of a series of bismuth-based oxide-modified TiO₂ as the photoanode for PEC valorization of cellulose in aqueous solution. The bismuth-based oxide was synthesized onto a TiO₂ photoanode by a chemical bath deposition (CBD) method followed by heat treatments. The composition of the materials was adjusted by varying the concentration of the Cu²⁺ and Bi³⁺ precursors. The research shows that Bi₂O₃ effectively suppresses the water oxidation reaction over TiO₂, a competitive side reaction in PEC cellulose oxidation, resulting in a Faradaic efficiency (FE) of 83.9 ± 4.9 % toward formate production. In contrast, unmodified TiO₂ photoanode only exhibits a FE of 25.3 ± 3.7 %. On the other hand, the photoelectrode showed insufficient oxidative force for both water and cellulose oxidation by the surface modification of CuBi₂O₄.

To improve the photocatalytic performance of carbon nitride (g-C₃N₄), a flower-shaped COCN/ZIS composite was synthesized by growing ZnIn₂S₄ (ZIS) onto structurally defective g-C₃N₄ (COCN) nanosheets. The experimental results indicate that the prepared photocatalyst has excellent photocatalytic performance for the degradation of methylene blue (MB), with an apparent rate constant of 0.0661 min⁻¹, which is approximately 6.89, 6.06 and 7.39 times greater than that of g-C₃N₄ (0.0096 min⁻¹), COCN (0.01091 min⁻¹) and ZIS (0.00895 min⁻¹), separately. The improvement in the photocatalytic performance of COCN/ZIS can be attributed to the defect structure of COCN and the well-matched relationship between COCN and ZIS, both of which result in valid photoinduced charge separation and migration. This has also been confirmed by the synergy coefficient (3.33). Furthermore, the total organic carbon content (TOC) removal rates of MB and wastewater by the 60-COCN/ZIS composite were 85.96 % and 75.32 %, respectively, suggesting that the resultant catalyst has potential application in the photodegradation treatment of MB. Finally, the capture experiments and electron paramagnetic resonance analysis show that ·OH, ·O₂^– and h⁺ species are generated during the process, among which ·OH plays a great part in the photodegradation of MB by the COCN/ZIS compound.