Photochem最新文献_第2页

Physicochemical Properties of Tungsten Trioxide Photoanodes Fabricated by Wet Coating of Soluble, Particulate, and Mixed Precursors 通过湿法涂覆可溶性、颗粒状和混合前驱体制造的三氧化钨光阳极的物理化学特性

Photochem Pub Date : 2024-02-01 DOI: 10.3390/photochem4010006

Valli Kamala Laxmi Ramya Chittoory, Marketa Filipsika, Radim Bartoš, M. Králová, P. Dzik

{"title":"Physicochemical Properties of Tungsten Trioxide Photoanodes Fabricated by Wet Coating of Soluble, Particulate, and Mixed Precursors","authors":"Valli Kamala Laxmi Ramya Chittoory, Marketa Filipsika, Radim Bartoš, M. Králová, P. Dzik","doi":"10.3390/photochem4010006","DOIUrl":"https://doi.org/10.3390/photochem4010006","url":null,"abstract":"Advanced oxidation processes are emerging technologies for the decomposition of organic pollutants in various types of water by harnessing solar energy. The purpose of this study is to examine the physicochemical characteristics of tungsten(VI) oxide (WO3) photoanodes, with the aim of enhancing oxidation processes in the treatment of water. The fabrication of WO3 coatings on conductive fluorine-doped tin oxide (FTO) substrates was achieved through a wet coating process that utilized three different liquid formulations: a dispersion of finely milled WO3 particles, a fully soluble WO3 precursor (acetylated peroxo tungstic acid), and a combination of both (applying a brick-and-mortar strategy). Upon subjecting the WO3 coatings to firing at a temperature of 450 °C, it was observed that their properties exhibited marked variations. The fabricated photoanodes are examined using a range of analytical techniques, including profilometry, thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), and voltammetry. The experimental data suggest that the layers generated through the combination of particulate ink and soluble precursor (referred to as the brick-and-mortar building approach) display advantageous physicochemical properties, rendering them suitable for use as photoanodes in photoelectrochemical cells.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139820931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Inverse Problems in Pump–Probe Spectroscopy 泵浦探针光谱学中的逆问题

Photochem Pub Date : 2024-01-31 DOI: 10.3390/photochem4010005

Denis S. Tikhonov, Diksha Garg, Melanie Schnell

引用次数: 0

The Rhodamine–Perylene Compact Electron Donor–Acceptor Dyad: Spin-Orbit Charge-Transfer Intersystem Crossing and the Energy Balance of the Triplet Excited States 罗丹明-苝紧密电子供体-受体二元体：自旋轨道电荷转移系统间交叉和三重激发态的能量平衡

Photochem Pub Date : 2024-01-29 DOI: 10.3390/photochem4010004

M. Imran, Dongyi Liu, Kaiyue Ye, Xue Zhang, Jianzhang Zhao

{"title":"The Rhodamine–Perylene Compact Electron Donor–Acceptor Dyad: Spin-Orbit Charge-Transfer Intersystem Crossing and the Energy Balance of the Triplet Excited States","authors":"M. Imran, Dongyi Liu, Kaiyue Ye, Xue Zhang, Jianzhang Zhao","doi":"10.3390/photochem4010004","DOIUrl":"https://doi.org/10.3390/photochem4010004","url":null,"abstract":"We prepared a rhodamine (RB)–perylene (Pery) compact electron donor/acceptor dyad (RB–Pery) to study the spin-orbit charge-transfer intersystem crossing (SOCT–ISC). The UV–vis absorption spectrum indicates a negligible electronic interaction between the donor and acceptor at ground state. However, the fluorescence of both the RB and Pery units are quenched in the dyad, which is attributed to the photoinduced electron transfer, supported by the electrochemical studies. Nanosecond transient absorption (ns-TA) spectra show delocalized triplet states, i.e., there is an excited-state equilibrium between Pery and the RB triplet states. The triplet state lifetime was determined as 109.8 μs. With intermolecular triplet–triplet energy transfer, monitored using ns-TA spectra, the triplet-state energy balance between RB and Pery in RB–Pery was confirmed. The proposed cascade photophysical processes of the dyad are 1RB*-Pery→RB–Pery+•→[3RB*-Pery↔RB-3Pery*]. Moreover, long-lived rhodamine radical cation (in milliseconds) was detected in both deaerated/aerated non-polar or low-polarity solvents (i.e., p-xylene, toluene). The potential energy curve of the dyad against the variation in the dihedral angle between the two units indicates large torsional freedom (53°~128°) in RB–Pery, which leads to inefficient SOCT–ISC; consequently, low singlet-oxygen quantum yields (ΦΔ = 2~8%) were observed.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140487206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Interactions of CdSe Nanocrystals with Cationic Proteins Extracted from Moringa oleifera Seeds 硒化镉纳米晶体与从辣木籽中提取的阳离子蛋白的相互作用

Photochem Pub Date : 2024-01-15 DOI: 10.3390/photochem4010003

L. Daniel, Salatiel Kapofi, Martha Kandawa-Schulz, H. Kwaambwa

{"title":"Interactions of CdSe Nanocrystals with Cationic Proteins Extracted from Moringa oleifera Seeds","authors":"L. Daniel, Salatiel Kapofi, Martha Kandawa-Schulz, H. Kwaambwa","doi":"10.3390/photochem4010003","DOIUrl":"https://doi.org/10.3390/photochem4010003","url":null,"abstract":"Even with significant developments in nanoscience, relatively little is known about the interactions of nanocrystal semiconducting materials with bio-macromolecules. To investigate the interfacial phenomena of cadmium selenide quantum dot (CdSe QD) nanocrystals with proteins extracted from Moringa oleifera seeds, different concentrations of cadmium selenide quantum dots–Moringa oleifera seed protein (CdSe–MSP) complexes were prepared. Respective CdSe QDs with hexagonal phase and crystalline size in the range of 4–7 nm were synthesized and labelled with the purified mesoporous MSP having a surface area of 8.4 m2/g. The interaction mechanism between CdSe QDs and MSP was studied using UV–Vis absorption, fluorescence emission and Fourier Transform Infrared spectroscopies. The UV–Vis absorption spectra showed absorption bands of CdSe–MSP complexes at 546.5 nm. The fluorescence intensity of CdSe QDs was found to decrease with increasing concentration of MSP. The thermodynamic potentials ∆Hθ (−321.3 × 103 Jmol−1); ∆Sθ (156.0 JK−1mol−1) and ∆Gθ (−46.6 × 103 Jmol−1) were also calculated. The stability of the complex found is strongly influenced by electrostatics interaction and surface-bound complexation equilibrium attraction. This information can help to elucidate the surface characteristics of MSP and its potential interactions with other molecules or nanoparticles.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139622071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Survey of T1 and T2 Energies of Intramolecular Singlet Fission Chromophores 分子内单子裂变色团的 T1 和 T2 能量调查

Photochem Pub Date : 2024-01-10 DOI: 10.3390/photochem4010002

Guoying Yao, Zhenyu Yang, T. Zeng

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Twisted 8-Acyl-1-dialkyl-amino-naphthalenes Emit from a Planar Intramolecular Charge Transfer Excited State 扭曲的 8-酰基-1-二烷基氨基萘发出平面分子内电荷转移激发态

Photochem Pub Date : 2024-01-04 DOI: 10.3390/photochem4010001

Christopher Abelt, Kirsten Sweigart

引用次数: 0

Recent Advances in Visible Light Photoinitiating Systems Based on Flavonoids 基于黄酮类化合物的可见光光引发体系的最新进展

Photochem Pub Date : 2023-12-12 DOI: 10.3390/photochem3040030

F. Dumur

引用次数: 0

Photolytic Degradation of the Insecticide Clothianidin in Hydrochar Aquatic Suspensions and Extracts 水生生物悬浮液和萃取物中杀虫剂噻虫胺的光解降解

Photochem Pub Date : 2023-11-07 DOI: 10.3390/photochem3040027

Artemis Pappa, Feidias Bairamis, Ioannis Konstantinou

{"title":"Photolytic Degradation of the Insecticide Clothianidin in Hydrochar Aquatic Suspensions and Extracts","authors":"Artemis Pappa, Feidias Bairamis, Ioannis Konstantinou","doi":"10.3390/photochem3040027","DOIUrl":"https://doi.org/10.3390/photochem3040027","url":null,"abstract":"In this study, the aqueous photolytic degradation of the neonicotinoid pesticide clothianidin was studied in suspensions and aqueous extracts of hydrochar produced from olive kernels. A slight and nonsignificant decrease in the photodegradation rate of clothianidin in aqueous extracts of hydrochar (HCw) with an initial concentration of hydrochar ranged from 50 to 400 mg L−1 (rate constants ranged between k = 0.0034 and 0.0039 min−1) was observed in comparison to the respective rate in the bi-distilled water (k = 0.0040 min−1). On the contrary, in the presence of hydrochar suspensions (HCp), a significant decrease was observed for 50 mg L−1 hydrochar particle concentration (k = 0.020 min−1), while for higher concentrations (100 to 400 mg L−1), rate constants increased but with nonsignificant differences compared with the kinetics followed in the absence of them. Generally, the photodegradation rate of clothianidin, in the presence of HCw and HCp, is reduced compared to the photodegradation rate in bi-distilled aqueous solutions, except in the case of the aqueous suspension with an HCp concentration of 200 mg L−1. The transformation products (TPs) of clothianidin formed in the photolytic degradation processes were identified using ultrahigh-performance liquid chromatography coupled with accurate high-resolution mass spectrometry technique (UHPLC-LTQ-ORBITRAP). The formation profiles of TPs varied according to the matrix showing different degrees of participation of direct and indirect (photosensitized) phototransformation pathways. Photolytic degradation of clothianidin takes place mainly through denitration, hydroxylation and dechlorination pathways. Finally, the toxicity of the identified TPs was studied using the Vibrio fischeri bioassay. Toxicity was slightly reduced after 300 min of irradiation while maximum value was observed after 180–240 min of irradiation showing the formation of more toxic TPs along the photochemical degradation.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135474596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Metal Ion-Induced Formation of Metallogels by Visible-Light-Responsive Phenylalanine-Functionalized Arylazopyrazole Ligands 金属离子诱导形成可见光响应苯丙氨酸功能化芳唑配体的金属凝胶

Photochem Pub Date : 2023-10-24 DOI: 10.3390/photochem3040026

Mikayla Browning, Alexandra Jefferson, Jazz Geter, Kesete Ghebreyessus

{"title":"Metal Ion-Induced Formation of Metallogels by Visible-Light-Responsive Phenylalanine-Functionalized Arylazopyrazole Ligands","authors":"Mikayla Browning, Alexandra Jefferson, Jazz Geter, Kesete Ghebreyessus","doi":"10.3390/photochem3040026","DOIUrl":"https://doi.org/10.3390/photochem3040026","url":null,"abstract":"A visible-light-responsive arylazopyrazole-functionalized phenylalanine (4-MeS-AAP-NF) derived ligand was designed and synthesized, and it was found to form metallogels with reversible photo-responsive properties in mixed methanol/water (MeOH/H2O) solvents. The gelation behavior of the 4-MeS-AAP-NF ligand in the presence of different divalent metal ions in mixed methanol/water (MeOH/H2O) solvents at pH~11.60 was studied. It was found that the 4-MeS-AAP-NF ligand alone could not self-assemble to form any gels. However, in the presence of divalent metal ions, it readily formed the assembled metallogels in an alkaline aqueous/methanol solution with various morphologies. The results suggest that the gelation process was triggered by divalent metal ions. The presence of the AAP moiety in the gel matrix rendered the metallogel assemblies photo-responsive, and the reversible gel-to-sol phase transition was studied by UV-vis spectroscopy. The gels showed a slow, reversible visible-light-induced gel-to-sol phase transition under blue (λ = 405 nm) and then sol-to-gel transition by green light (λ = 530 nm) irradiation, resulting in the re-formation of the original gel state. The morphology and viscoelastic properties of the yellow–orange opaque metallogels were characterized by scanning electron microscopy (SEM) and rheological measurement, respectively.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135316251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Photochemistry of β-γ-Unsaturated Spirolactones β-γ-不饱和螺内酯的光化学性质

Photochem Pub Date : 2023-10-17 DOI: 10.3390/photochem3040025

Werner Fudickar, Melanie Metz, Tobias Krüger-Braunert, Alexandra Kelling, Eric Sperlich, Pablo Wessig, Torsten Linker

{"title":"Photochemistry of β-γ-Unsaturated Spirolactones","authors":"Werner Fudickar, Melanie Metz, Tobias Krüger-Braunert, Alexandra Kelling, Eric Sperlich, Pablo Wessig, Torsten Linker","doi":"10.3390/photochem3040025","DOIUrl":"https://doi.org/10.3390/photochem3040025","url":null,"abstract":"β-γ-unsaturated spirolactones are easily available by Birch reduction. We describe their photochemistry in the presence of or without carbonyl compounds. The spirolactones show a distinct absorption band at 230 nm, which is not present in other cyclohexadienes. We explain this behavior by an interaction of the double bonds with the carbonyl group through space, further proven by TDDFT calculations. This allows their direct excitation with UV-C light. Interestingly, we obtain only products of an oxa-di-π-methane rearrangement, hitherto unknown for lactones. This speaks for a reaction pathway starting from singlet states, confirmed by calculated relative energies of biradical intermediates. Although polymerization is the main side reaction, we were able to isolate tricyclic lactones in moderate yields in a pure form. In the presence of benzaldehyde or benzophenone, excitation with UV-B light was possible, leading to H-atom abstraction in the allylic position and formation of alcohols. With an electron-rich double bond, the Paternó–Büchi products were isolated as well. The different diastereomers were separated by column chromatography or HPLC. Their relative configurations were determined using NOESY measurements or X-ray structure analysis. Overall, β-γ-unsaturated spirolactones show a remarkably different photochemistry compared to other cyclohexadienes, affording new products in only a few steps.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135993835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0