Journal of Photochemistry and Photobiology A-chemistry最新文献

Designing of materials for organic solar cells is a tedious process. In present study, machine learning (ML) is used to predict the power conversion efficiency (PCE). Over 40 ML models are tried. Gradient boosting regression is appeared as best model. 10k small molecule donors are designed. Their PCE values are predicted using best model. The library of generated donors is visualized using various tools. Chemical similarity analysis is done to study structural behavior of selected donors. Reasonable resemblance is found. Synthetic accessibility assessment has indicated easy synthesis for majority of selected small molecule donors. The introduced framework has ability to find the efficient materials in short time.

Many research studies have been conducted into the applications of the heterostructures of graphene (Gr) and boron carbide (BC₃) in real-world devices after they were synthesized successfully by researchers. Thanks to their unique electronic attributes and high surface-to-volume ratio, the above-mentioned two-dimensional nanosheets (NSs) such as have enjoyed the interest of many research groups and scientists. Within this piece of research, the electronic and structural attributes of pure Gr (PGr), pure BC₃ (PBC₃) and their in-plane heterostructures were investigated by employing the DFT along with the density functionals B3LYP and WB97XD. The results demonstrated that by increasing the concentration of the B-C, there was a gradual increase in the bandgap. Also, the structural stability of the NSs was good and the cohesive energy was favourable. In addition, the adhesion attributes of these NSs were investigated towards two toxic gasses, namely CO and SO₂. Amongst the heterostructures, after exposure to CO and SO₂, the adhesion energy of GBC₃I was greater, which was approximately −0.487 eV and −0.229 eV, respectively. Following the adhesion of SO₂ onto the surface of the NSs, apart from the PGr, there was a significant change in their electronic attributes such as conductance, workfunction, Fermi level, the LUMO, the HOMO and the bandgap. However, following the adhesion of CO, the above-mentioned attributed remained almost the same. Based on the NBO and Mulliken charge analysis, there was a charge transport from the gasses to the NSs. Despite the fact that the adhesion energies for CO were relative higher than the adhesion energies for SO₂ for the NSs, the analysis of the MEP maps, the charge transport and the electronic attributes demonstrated that the NSs can be used as promising nanosensors for the detection of SO₂ rather than CO.

New versatile Schiff base gelator (HL) and its highly selective Ni(II)-and Yb(III)-based metallogels 1–2 have been synthesized and characterized by spectral techniques. Gelator HL in presence of triethylamine (Et₃N) with Ni(NO₃)₂·6H₂O and anhydrous Yb(NO₃)₃ in DMF/MeOH(1:1) solvents forms MG1 and MG2 supramolecular gels, respectively at room temperature (rt). Rheological results show thermal stability up to 100 ℃ and structurally rigid nature of MG1 and MG2. Remarkably, MG1 and MG2 were examined for identification of cations, anions, nitroaromatics and aromatic amines (AAs) but unable to recognize any analytes except for m-phenylenediamine (MPD) by using MG1. Metallogel MG1 shows highly selective response to MPD environmental pollutant with a limit of detection (LoD) of 7.58 × 10^-7 M, without any interference of competing analytes. Interestingly, depending upon fascinating fluorescent On-Off-On switching behavior, molecular logic device has been fabricated with AND and IMPLICATION-logic gates function by employing the chemical inputs (i) HB, Ni(II) (MG1), Yb(III) (MG2) and (ii) HB, MG1 and MPD based on emission change at different wavelengths as output signal.

A polarity-sensitive single-fluorophore and -component system probe An-EA was able to generate tunable luminescence as well as white-light (0.33, 0.36) due to a broad emission spectrum containing monomer and excimer bands that are associated with nanoparticles and aggregated fiber formation, respectively in an aqueous media. In addition to the spectroscopic evidence for monomer and excimer properties in aggregated states, transient absorption spectroscopy was used to investigate charge-transfer properties between donor aniline and acceptor anthracene.

To address the low accuracy of pesticide residue detection in traditional Chinese medicine, we developed a biosensor for acetamiprid detection. First, an oxidized single-walled carbon nanohorn capable of adsorbing and quenching fluorescence was prepared. Second, a novel fluorescence sensing system was constructed based on this nanomaterial. The detection performance of the sensor system was evaluated, which revealed that fluorescence quenching by the biosensor was primarily due to the adsorption of the aptamer by the nanomaterials. Optimal conditions were found to be a nanomaterial mass concentration of 800 ng/mL and an incubation time of 70 min, which resulted in the best fluorescence response. Under these optimal conditions, the system was used to detect acetamiprid residues in traditional Chinese medicine. The fluorescence intensity showed a strong linear relationship with acetamiprid concentration, with a correlation coefficient of 0.9985 and a detection limit of 6.33 ng/mL. In the sample test, the biosensor demonstrated high accuracy, with good average recovery rates and low relative standard deviation. The system showed excellent selectivity and detection performance, with no interference from other pesticides.

Herein, chromium trioxide (Cr₂O₃) doped Polyvinylpyrrolidone (PVP) nanofibers with high crystallinity and UV light sensitivity are successfully grown onto the glass substrates by electrospun deposition at room temperature. The effect of Cr₂O₃ concentration on the morphology, structure, and photoluminescence properties of the as-fabricated PVP nanofibers is examined. With the increase in doping concentration of Cr₂O₃ (i.e., 1, 2 and 3 %), the direct band gap of PVP nanofibers is reduced to 4.05, 4.01, and 3.85 eV, respectively. XRD and FE-SEM results manifest that the crystallinity and diameter of the nanofibers are dependent upon Cr₂O₃ concentration, i.e., the mean diameter decreases from 600 to 200 nm. Photoluminescence spectra indicate higher UV emission upon the addition of Cr₂O₃, with greater emission near the band edge for thinner nanofibers. A possible mechanism for the formation of PVP/Cr₂O₃ nanofibers is addressed in detail. Furthermore, it is found that the sensitivity of the as-fabricated PVP/Cr₂O₃ detector to UV-light emission strongly depends on Cr₂O₃ concentration, i.e., good responsivity (2.257 A/W) and specific detectives (9.8 $\times$ 10¹² cm Hz^1/2/W) at a Cr₂O₃ concentration of 2 % are achieved at a wavelength of 454.1 nm, besides recording the lowest rise and fall times.

In this work, a fluorescence probe TBO-CarE derived from the triphenylamine-benzofuranone backbone and the carbamate response group was developed for monitoring carboxylesterases (CEs) and its imaging in drug-induced liver cellular injury. TBO-CarE suggested the advantages including relatively high sensitivity, high selectivity, relatively rapid response, and high stability in the solution system. On the basis of the low cyto-toxicity upon living liver cell lines, TBO-CarE was able to monitor the endogenous CEs level in both the inhibitory and induced status. Furthermore, TBO-CarE achieved monitoring both the occurrence and treatment of the acetaminophen-induced cellular liver injury via visualizing the CEs level. This work was informative for developing convenient CEs imaging implement and the potential screening approach for medicinal agents.

An alkyl chain engineering strategy is described to design mechanochromic and vapochromic response molecules with dual state emission. Based on a red emissive AIE-active fluorophore (NAPTPA-phenol), the alkyl chains with different length (C2 ∼ C8) are introduced to construct NAPTPA1-4 via an ester linker. All four compounds display dramatic emissions in both aggregation and solid states, which showed higher quantum yields than their precursor NAPTPA-phenol. Among these compounds, NAPTPA1 with the C2 alkyl chain shows the largest bathochromic shift (∼50 nm) from 560 nm (Φ = 92.2 %) to 610 nm (Φ = 59.2 %) between two solid states. The large shift might be assigned to the efficient intramolecular charge transfer between naphthalimide and triphenylamine and two different stacking modes (self-assembly and amorphous). The high fluorescence quantum yields in aggregation state should be attributed to restricted of intramolecular rotation of the rotor-shape 4-arylnaphthalimide fluorophores. Furthermore, the needle-like self-assembly structure is seen in the SEM pattern of NAPTPA1, which exhibited large difference comparing to NAPTPA-phenol and NAPTPA2 ∼ 4. After grinding, the amorphous forms were given to all compounds that led their similar emission bands in red region centered on 610 nm. With the dramatic dual emission color, NAPTPA1 with short side chain (C2) was used to perform a vapochromic reverse courses by using the common VOCs to fume the NAPTPA1-loaded filter paper. The test exhibits the obvious color transformation and fast reversing time (<20 s) indicating the test strip can be successfully implemented to monitor VOCs.

Aluminium (Al³⁺) and hypochlorite (ClO⁻) have toxic effects on plants, affecting various physiological processes and ultimately impacting plant growth and development. Hence, the preparation of a smart tool for the detection of hypochlorite (ClO⁻) and Aluminium (Al³⁺) in water, a dual-target fluorescent chemosensor APC (anthracene-pyridine conjugate) has been synthesized. APC holds a unique diimine character when compared with a few similar diimine and interacts with both Al³⁺ and ClO⁻ through charge transfer and chemodosimetric mechanisms to display green and blue fluorescence, correspondingly.The detection limits of APC for Al³⁺ and ClO⁻ are 0.68 µM and 0.25 µM, respectively. The binding ratio between APC and Al³⁺ has been determined as 1:1 from Jobs plot analysis. The sensing mechanisms of APC with Al³⁺ and ClO⁻ have been established by UV–visible, ¹H NMR titration, HRMS analysis and theoretical calculations. This method has been successfully employed to examine the consequences of continued exposure to high concentrations of aluminium and hypochlorite on marigold and lettuce plants, respectively.

The present investigation explored the impact of solvothermal reaction time on the adsorption properties of synthesized spinel ZnFe₂O₄ Nanoparticles (ZF NPs) and their photocatalytic activity for the degradation of congo red (CR) dye. The structure, morphology and chemical composition is identified for the synthesized ZF NPs. The reaction times for the solvothermal synthesis of ZF NPs were investigated at time intervals of 6 hrs and 18 hrs which are denoted as ZF-6 h and ZF-18 h respectively. The XRD confirms the formation of spinel-type ZF-6 h and ZF-18 h with crystallite size of 5.50 nm and 8.36 nm for ZF-6 h and ZF-18 h respectively. The FESEM image of ZF-6 h exhibits microspheres, whereas in ZF-18 h NPs, the microspheres undergoes deformation. TEM analysis of ZF-6 h revealed that the microspheres were consists of 8–10 nm size ZF-NPs. Raman spectroscopy and XPS studies indicates, the reaction time influence the occupancy with 64 % and 32 % of inversion of Zn²⁺ cations from tetrahedral to octahedral sites in ZF-6 h and ZF-18 h, respectively. The surface area of mesoporous ZF-6 h and ZF-18 h are 138.29 m²/g and 128.41 m²/g respectively as confirmed using BET and BJH techniques. The CR dye adsorption capacity of 123.73 mg/g for ZF-6 h is higher compared to ZF-18 h (99.93 mg/g). The maximum dye removal efficiency evaluated for ZF-6 h NPs and ZF-18 h NPs was 87.33 % and 73.09 % respectively upon exposure of natural sunlight. The recyclability study identifies that ZF-6 h NPs remain stable for three degradation cycles. These results indicate that reaction time in solvothermal synthesis is sensitive to the morphology and physicochemical properties of ZF NPs. The enhanced performance of such ZF NPs is attributed to the synergistic effect of adsorption followed by photocatalytic (photo-Fenton) degradation of dyes.