Pub Date : 2024-07-14DOI: 10.3390/photochem4030018
María Ángeles Cortés, Carlos Díaz, R. de la Campa, A. Presa-Soto, María Luisa Valenzuela
Starting from poly(4-vinylpyridine) ((P4VP)n), poly(2-vinylpyridine) ((P2VP)n), and [N=P(O2CH2CF3)]m-b-P2VP20 block copolymers, a series of metal-containing homopolymers, (P4VP)n⊕MXm, (P2VP)n⊕MXm, and [N=P(O2CH2CF3)]m-b-P2VP20]⊕MXm MXm = PtCl2, ZnCl2, and Eu(NO3)3, have been successfully prepared by using a direct and simple solution methodology. Solid-state pyrolysis of the prepared metal-containing polymeric precursors led to the formation of a variety of different metallic and metal oxide nanoparticles (Pt, ZnO, Eu2O3, and EuPO4) depending on the composition and nature of the polymeric template precursor. Thus, whereas Eu2O3 nanostructures were obtained from europium-containing homopolymers ((P4VP)n⊕MXm and (P2VP)n⊕MXm), EuPO4 nanostructures were achieved using phosphorus-containing block copolymer precursors, [N=P(O2CH2CF3)]m-b-P2VP20]⊕MXm with MXm = Eu(NO3)3. Importantly, and although both Eu2O3 and EuPO4 nanostructures exhibited a strong luminescence emission, these were strongly influenced by the nature and composition of the macromolecular metal-containing polymer template. Thus, for P2VP europium-containing homopolymers ((P4VP)n⊕MXm and (P2VP)n⊕MXm), the highest emission intensity corresponded to the lowest-molecular-weight homopolymer template, [P4VP(Eu(NO3)3]6000, whereas the opposite behavior was observed when block copolymer precursors, [N=P(O2CH2CF3)]m-b-P2VP20]⊕MXm MXm= Eu(NO3)3, were used (highest emission intensity corresponded to [N=P(O2CH2CF3)]100-b-[P2VP(Eu(NO3)3)x]20). The intensity ratio of the emission transitions: 5D0 → 7F2/5D0 → 7F1, suggested a different symmetry around the Eu3+ ions depending on the nature of the polymeric precursor, which also influenced the sizes of the prepared Pt°, ZnO, Eu2O3, and EuPO4 nanostructures.
从聚（4-乙烯基吡啶）（(P4VP)n）、聚（2-乙烯基吡啶）（(P2VP)n）和[N=P(O2CH2CF3)]m-b-P2VP20 嵌段共聚物开始，产生了一系列含金属的均聚物、(P4VP)n⊕MXm, (P2VP)n⊕MXm, and [N=P(O2CH2CF3)]m-b-P2VP20]⊕MXm MXm = PtCl2, ZnCl2, and Eu(NO3)3, have been successfully prepared by using a direct and simple solution methodology.对所制备的含金属聚合物前驱体进行固态热解，可形成各种不同的金属和金属氧化物纳米粒子（Pt、ZnO、Eu2O3 和 EuPO4），具体取决于聚合物模板前驱体的成分和性质。因此，Eu2O3 纳米结构是通过含铕均聚物（(P4VP)n⊕MXm 和 (P2VP)n⊕MXm）获得的，而 EuPO4 纳米结构则是通过含磷嵌段共聚物前体 [N=P(O2CH2CF3)]m-b-P2VP20]⊕MXm 获得的，其中 MXm = Eu(NO3)3。重要的是，尽管 Eu2O3 和 EuPO4 纳米结构都能发出强烈的荧光，但它们都受到含金属的大分子聚合物模板的性质和组成的强烈影响。因此，对于含铕的 P2VP 均聚物（(P4VP)n⊕MXm 和 (P2VP)n⊕MXm），发射强度最高的是分子量最低的均聚物模板 [P4VP(Eu(NO3)3]6000、而使用嵌段共聚物前体 [N=P(O2CH2CF3)]m-b-P2VP20]⊕MXm MXm= Eu(NO3)3（[N=P(O2CH2CF3)]100-b-[P2VP(Eu(NO3)3)x]20）时则相反（[N=P(O2CH2CF3)]100-b-[P2VP(Eu(NO3)3)x]20 的发射强度最高）。发射跃迁的强度比为5D0 → 7F2/5D0 → 7F1，表明 Eu3+ 离子周围的不同对称性取决于聚合物前体的性质，这也影响了制备的 Pt°、ZnO、Eu2O3 和 EuPO4 纳米结构的尺寸。
{"title":"Synthesis of Metallic and Metal Oxide Nanoparticles Using Homopolymers as Solid Templates: Luminescent Properties of the Eu+3 Nanoparticle Products","authors":"María Ángeles Cortés, Carlos Díaz, R. de la Campa, A. Presa-Soto, María Luisa Valenzuela","doi":"10.3390/photochem4030018","DOIUrl":"https://doi.org/10.3390/photochem4030018","url":null,"abstract":"Starting from poly(4-vinylpyridine) ((P4VP)n), poly(2-vinylpyridine) ((P2VP)n), and [N=P(O2CH2CF3)]m-b-P2VP20 block copolymers, a series of metal-containing homopolymers, (P4VP)n⊕MXm, (P2VP)n⊕MXm, and [N=P(O2CH2CF3)]m-b-P2VP20]⊕MXm MXm = PtCl2, ZnCl2, and Eu(NO3)3, have been successfully prepared by using a direct and simple solution methodology. Solid-state pyrolysis of the prepared metal-containing polymeric precursors led to the formation of a variety of different metallic and metal oxide nanoparticles (Pt, ZnO, Eu2O3, and EuPO4) depending on the composition and nature of the polymeric template precursor. Thus, whereas Eu2O3 nanostructures were obtained from europium-containing homopolymers ((P4VP)n⊕MXm and (P2VP)n⊕MXm), EuPO4 nanostructures were achieved using phosphorus-containing block copolymer precursors, [N=P(O2CH2CF3)]m-b-P2VP20]⊕MXm with MXm = Eu(NO3)3. Importantly, and although both Eu2O3 and EuPO4 nanostructures exhibited a strong luminescence emission, these were strongly influenced by the nature and composition of the macromolecular metal-containing polymer template. Thus, for P2VP europium-containing homopolymers ((P4VP)n⊕MXm and (P2VP)n⊕MXm), the highest emission intensity corresponded to the lowest-molecular-weight homopolymer template, [P4VP(Eu(NO3)3]6000, whereas the opposite behavior was observed when block copolymer precursors, [N=P(O2CH2CF3)]m-b-P2VP20]⊕MXm MXm= Eu(NO3)3, were used (highest emission intensity corresponded to [N=P(O2CH2CF3)]100-b-[P2VP(Eu(NO3)3)x]20). The intensity ratio of the emission transitions: 5D0 → 7F2/5D0 → 7F1, suggested a different symmetry around the Eu3+ ions depending on the nature of the polymeric precursor, which also influenced the sizes of the prepared Pt°, ZnO, Eu2O3, and EuPO4 nanostructures.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141649994","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}
Perovskite solar cells with an indium tin oxide (ITO)/SnO2/CH3NH3PbI3/Spiro-OMeTAD/2,2,2-trifluoroethanol (TFE) doped single-walled carbon nanotube (SWCNT) structure were developed by dropping TFE onto SWCNTs, which replaced the metal back electrode, and a conversion efficiency of 14.1% was achieved. Traditionally, acidic doping of the back electrode, SWCNT, has been challenging due to the potential damage it may cause to the perovskite layer. However, TFE has facilitated easy doping of SWCNT as the back electrode. The sheet resistance of the SWCNTs decreased and their ionization potential shifted to deeper levels, resulting in improved hole transport properties with a lower barrier to carrier transport. Furthermore, the Seebeck coefficient (S) increased from 34.5 μV/K to 73.1 μV/K when TFE was dropped instead of EtOH, indicating an enhancement in the behavior of p-type charge carriers. It was observed that hydrophilic substances adhered less to the SWCNT surface, and the formation of PbI2 was suppressed. These effects resulted in higher conversion efficiency and improved solar cell performance. Furthermore, the decrease in conversion efficiency after 260 days was suppressed, showing improved durability. The study suggests that combining SWCNTs and TFEs improves solar cell performance and stability.
{"title":"Facile Doping of 2,2,2-Trifluoroethanol to Single-Walled Carbon Nanotubes Electrodes for Durable Perovskite Solar Cells","authors":"Naoki Ueoka, Achmad Syarif Hidayat, Hisayoshi Oshima, Yoshimasa Hijikata, Yutaka Matsuo","doi":"10.3390/photochem4030019","DOIUrl":"https://doi.org/10.3390/photochem4030019","url":null,"abstract":"Perovskite solar cells with an indium tin oxide (ITO)/SnO2/CH3NH3PbI3/Spiro-OMeTAD/2,2,2-trifluoroethanol (TFE) doped single-walled carbon nanotube (SWCNT) structure were developed by dropping TFE onto SWCNTs, which replaced the metal back electrode, and a conversion efficiency of 14.1% was achieved. Traditionally, acidic doping of the back electrode, SWCNT, has been challenging due to the potential damage it may cause to the perovskite layer. However, TFE has facilitated easy doping of SWCNT as the back electrode. The sheet resistance of the SWCNTs decreased and their ionization potential shifted to deeper levels, resulting in improved hole transport properties with a lower barrier to carrier transport. Furthermore, the Seebeck coefficient (S) increased from 34.5 μV/K to 73.1 μV/K when TFE was dropped instead of EtOH, indicating an enhancement in the behavior of p-type charge carriers. It was observed that hydrophilic substances adhered less to the SWCNT surface, and the formation of PbI2 was suppressed. These effects resulted in higher conversion efficiency and improved solar cell performance. Furthermore, the decrease in conversion efficiency after 260 days was suppressed, showing improved durability. The study suggests that combining SWCNTs and TFEs improves solar cell performance and stability.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141649715","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}
Pub Date : 2024-04-17DOI: 10.3390/photochem4020012
I. Natali Sora, Francesca Fontana, R. Pelosato, B. Bertolotti
This review summarizes the progress over the last fifteen years in visible light reactive photocatalysts for environmental arsenic remediation. The design and performance of several materials including (1) doped and surface functionalized TiO2, (2) binary composites combining TiO2 with another semiconductor that absorbs visible light radiation or a metal (Pt), (3) ternary composites incorporating TiO2, a conductive polymer that can retard electron-hole recombination and an excellent adsorbent material for the removal of As(V), (4) tungsten, zinc, and bismuth oxides, (5) g-C3N4 based catalysts, and (6) M@AgCl core–shell structures. These results show that long reaction time remains a major challenge in achieving high As(III) oxidation.
{"title":"A Review of Visible Light Responsive Photocatalysts for Arsenic Remediation in Water","authors":"I. Natali Sora, Francesca Fontana, R. Pelosato, B. Bertolotti","doi":"10.3390/photochem4020012","DOIUrl":"https://doi.org/10.3390/photochem4020012","url":null,"abstract":"This review summarizes the progress over the last fifteen years in visible light reactive photocatalysts for environmental arsenic remediation. The design and performance of several materials including (1) doped and surface functionalized TiO2, (2) binary composites combining TiO2 with another semiconductor that absorbs visible light radiation or a metal (Pt), (3) ternary composites incorporating TiO2, a conductive polymer that can retard electron-hole recombination and an excellent adsorbent material for the removal of As(V), (4) tungsten, zinc, and bismuth oxides, (5) g-C3N4 based catalysts, and (6) M@AgCl core–shell structures. These results show that long reaction time remains a major challenge in achieving high As(III) oxidation.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140693718","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}
Pub Date : 2024-04-09DOI: 10.3390/photochem4020011
Konstantin Moritz Knötig, Domenic Gust, K. Oum, T. Lenzer
Thin films of carbazole (Cz) derivatives are frequently used in organic electronics, such as organic light-emitting diodes (OLEDs). Because of the proximity of the Cz units, the excited-state relaxation in such films is complicated, as intermolecular pathways, such as singlet–singlet annihilation (SSA), kinetically compete with the emission. Here, we provide an investigation of two benchmark systems employing neat carbazole and 3,6-di-tert-butylcarbazole (t-Bu-Cz) films and also their thin film blends with poly(methyl methacrylate) (PMMA). These are investigated by a combination of atomic force microscopy (AFM), femtosecond and nanosecond transient absorption spectroscopy (fs-TA and ns-TA) and time-resolved fluorescence. Excitonic J-aggregate-type features are observed in the steady-state absorption and emission spectra of the neat films. The S1 state shows a broad excited-state absorption (ESA) spanning the entire UV–Vis–NIR range. At high S1 exciton number densities of about 4 × 1018 cm−3, bimolecular diffusive S1–S1 annihilation is found to be the dominant SSA process in the neat films with a rate constant in the range of 1–2 × 10−8 cm3 s−1. SSA produces highly vibrationally excited molecules in the electronic ground state (S0*), which cool down slowly by heat transfer to the quartz substrate. The results provide relevant photophysical insight for a better microscopic understanding of carbazole relaxation in thin-film environments.
{"title":"Excited-State Dynamics of Carbazole and tert-Butyl-Carbazole in Thin Films","authors":"Konstantin Moritz Knötig, Domenic Gust, K. Oum, T. Lenzer","doi":"10.3390/photochem4020011","DOIUrl":"https://doi.org/10.3390/photochem4020011","url":null,"abstract":"Thin films of carbazole (Cz) derivatives are frequently used in organic electronics, such as organic light-emitting diodes (OLEDs). Because of the proximity of the Cz units, the excited-state relaxation in such films is complicated, as intermolecular pathways, such as singlet–singlet annihilation (SSA), kinetically compete with the emission. Here, we provide an investigation of two benchmark systems employing neat carbazole and 3,6-di-tert-butylcarbazole (t-Bu-Cz) films and also their thin film blends with poly(methyl methacrylate) (PMMA). These are investigated by a combination of atomic force microscopy (AFM), femtosecond and nanosecond transient absorption spectroscopy (fs-TA and ns-TA) and time-resolved fluorescence. Excitonic J-aggregate-type features are observed in the steady-state absorption and emission spectra of the neat films. The S1 state shows a broad excited-state absorption (ESA) spanning the entire UV–Vis–NIR range. At high S1 exciton number densities of about 4 × 1018 cm−3, bimolecular diffusive S1–S1 annihilation is found to be the dominant SSA process in the neat films with a rate constant in the range of 1–2 × 10−8 cm3 s−1. SSA produces highly vibrationally excited molecules in the electronic ground state (S0*), which cool down slowly by heat transfer to the quartz substrate. The results provide relevant photophysical insight for a better microscopic understanding of carbazole relaxation in thin-film environments.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140722913","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}
Pub Date : 2024-03-28DOI: 10.3390/photochem4020009
Ashim Pramanik, M. M. Calvino, L. Sciortino, P. Pasbakhsh, G. Cavallaro, G. Lazzara, Fabrizio Messina, A. Sciortino
This study explores the use of Halloysite NanoTubes (HNTs) as photocatalysts capable of decomposing organic dyes under exposure to visible or ultraviolet light. Through a systematic series of photocatalytic experiments, we unveil that the photodegradation of Rhodamine B, used as a model cationic dye, is significantly accelerated in the presence of HNTs. We observe that the extent of RhB photocatalytic degradation in 100 min in the presence of the HNTs is ~four times higher compared to that of bare RhB. Moreover, under optimized conditions, the as-extracted photodegradation rate of RhB (~0.0022 min−1) is comparable to that of the previously reported work on the photodegradation of RhB in the presence of tubular nanostructures. A parallel effect is observed for anionic Coumarin photodegradation, albeit less efficiently. Our analysis attributes this discrepancy to the distinct charge states of the two dyes, influencing their attachment sites on HNTs. Cationic Rhodamine B molecules preferentially attach to the outer surface of HNTs, while anionic Coumarin molecules tend to attach to the inner surface. By leveraging the unique properties of HNTs, a family of naturally occurring nanotube structures, this research offers valuable insights for optimizing photocatalytic systems in the pursuit of effective and eco-friendly solutions for environmental remediation.
{"title":"Charge-Selective Photocatalytic Degradation of Organic Dyes Driven by Naturally Occurring Halloysite Nanotubes","authors":"Ashim Pramanik, M. M. Calvino, L. Sciortino, P. Pasbakhsh, G. Cavallaro, G. Lazzara, Fabrizio Messina, A. Sciortino","doi":"10.3390/photochem4020009","DOIUrl":"https://doi.org/10.3390/photochem4020009","url":null,"abstract":"This study explores the use of Halloysite NanoTubes (HNTs) as photocatalysts capable of decomposing organic dyes under exposure to visible or ultraviolet light. Through a systematic series of photocatalytic experiments, we unveil that the photodegradation of Rhodamine B, used as a model cationic dye, is significantly accelerated in the presence of HNTs. We observe that the extent of RhB photocatalytic degradation in 100 min in the presence of the HNTs is ~four times higher compared to that of bare RhB. Moreover, under optimized conditions, the as-extracted photodegradation rate of RhB (~0.0022 min−1) is comparable to that of the previously reported work on the photodegradation of RhB in the presence of tubular nanostructures. A parallel effect is observed for anionic Coumarin photodegradation, albeit less efficiently. Our analysis attributes this discrepancy to the distinct charge states of the two dyes, influencing their attachment sites on HNTs. Cationic Rhodamine B molecules preferentially attach to the outer surface of HNTs, while anionic Coumarin molecules tend to attach to the inner surface. By leveraging the unique properties of HNTs, a family of naturally occurring nanotube structures, this research offers valuable insights for optimizing photocatalytic systems in the pursuit of effective and eco-friendly solutions for environmental remediation.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140372061","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}
Pub Date : 2024-02-09DOI: 10.3390/photochem4010008
David C. Bain, Julia Chang, Yihuan Lai, Thomas Khazanov, Phillip J. Milner, A. Musser
Cumulenes are linear molecules consisting of consecutive double bonds linking chains of sp-hybridized carbon atoms. They have primarily been of interest for potential use as molecular wires or in other nanoscale electronic devices, but more recently, other applications such as catalysis or even light harvesting through singlet fission have been speculated. Despite the recent theoretical and experimental interest, the photoexcitation of cumulenes typically results in quenching on the picosecond timescale, and the exact quenching mechanism for even the simplest of [3]-cumulenes lacks a clear explanation. In this report, we perform transient absorption spectroscopy on a set of model [3]-cumulene derivatives in a wide range of environmental conditions to demonstrate that the planarization of phenyl groups ultimately quenches the excited state. By restricting this intramolecular motion, we increase the excited state lifetime by a few nanoseconds, strongly enhancing photoluminescence and demonstrating an approach to stabilize them for photochemical applications.
{"title":"Torsional Disorder in Tetraphenyl [3]-Cumulenes: Insight into Excited State Quenching","authors":"David C. Bain, Julia Chang, Yihuan Lai, Thomas Khazanov, Phillip J. Milner, A. Musser","doi":"10.3390/photochem4010008","DOIUrl":"https://doi.org/10.3390/photochem4010008","url":null,"abstract":"Cumulenes are linear molecules consisting of consecutive double bonds linking chains of sp-hybridized carbon atoms. They have primarily been of interest for potential use as molecular wires or in other nanoscale electronic devices, but more recently, other applications such as catalysis or even light harvesting through singlet fission have been speculated. Despite the recent theoretical and experimental interest, the photoexcitation of cumulenes typically results in quenching on the picosecond timescale, and the exact quenching mechanism for even the simplest of [3]-cumulenes lacks a clear explanation. In this report, we perform transient absorption spectroscopy on a set of model [3]-cumulene derivatives in a wide range of environmental conditions to demonstrate that the planarization of phenyl groups ultimately quenches the excited state. By restricting this intramolecular motion, we increase the excited state lifetime by a few nanoseconds, strongly enhancing photoluminescence and demonstrating an approach to stabilize them for photochemical applications.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139789514","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}
Pub Date : 2024-02-09DOI: 10.3390/photochem4010008
David C. Bain, Julia Chang, Yihuan Lai, Thomas Khazanov, Phillip J. Milner, A. Musser
Cumulenes are linear molecules consisting of consecutive double bonds linking chains of sp-hybridized carbon atoms. They have primarily been of interest for potential use as molecular wires or in other nanoscale electronic devices, but more recently, other applications such as catalysis or even light harvesting through singlet fission have been speculated. Despite the recent theoretical and experimental interest, the photoexcitation of cumulenes typically results in quenching on the picosecond timescale, and the exact quenching mechanism for even the simplest of [3]-cumulenes lacks a clear explanation. In this report, we perform transient absorption spectroscopy on a set of model [3]-cumulene derivatives in a wide range of environmental conditions to demonstrate that the planarization of phenyl groups ultimately quenches the excited state. By restricting this intramolecular motion, we increase the excited state lifetime by a few nanoseconds, strongly enhancing photoluminescence and demonstrating an approach to stabilize them for photochemical applications.
{"title":"Torsional Disorder in Tetraphenyl [3]-Cumulenes: Insight into Excited State Quenching","authors":"David C. Bain, Julia Chang, Yihuan Lai, Thomas Khazanov, Phillip J. Milner, A. Musser","doi":"10.3390/photochem4010008","DOIUrl":"https://doi.org/10.3390/photochem4010008","url":null,"abstract":"Cumulenes are linear molecules consisting of consecutive double bonds linking chains of sp-hybridized carbon atoms. They have primarily been of interest for potential use as molecular wires or in other nanoscale electronic devices, but more recently, other applications such as catalysis or even light harvesting through singlet fission have been speculated. Despite the recent theoretical and experimental interest, the photoexcitation of cumulenes typically results in quenching on the picosecond timescale, and the exact quenching mechanism for even the simplest of [3]-cumulenes lacks a clear explanation. In this report, we perform transient absorption spectroscopy on a set of model [3]-cumulene derivatives in a wide range of environmental conditions to demonstrate that the planarization of phenyl groups ultimately quenches the excited state. By restricting this intramolecular motion, we increase the excited state lifetime by a few nanoseconds, strongly enhancing photoluminescence and demonstrating an approach to stabilize them for photochemical applications.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139849293","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}
Pub Date : 2024-02-06DOI: 10.3390/photochem4010007
Jacobo Soilán, Leonardo López-Cóndor, Beatriz Peñín, José Aguilera, M. V. de Gálvez, Diego Sampedro, R. Losantos
Avobenzone is one of the most widely used sunscreens in skin care formulations, but suffers from some drawbacks, including photo instability. To mitigate this critical issue, the use of octocrylene as a stabilizer is a common approach in these products. However, octocrylene has been recently demonstrated to show potential phototoxicity. The aim of this work is to analyze the performance of a series of mycosporine-like amino acid (MAA)-inspired compounds to act as avobenzone stabilizers as an alternative to octocrylene. Different avobenzone/MAA analogue combinations included in galenic formulations were followed under increasing doses of solar-simulated UV radiation. Some of the synthetic MAA analogues analyzed were able to increase by up to two times the UV dose required for 50% of avobenzone photobleaching. We propose some of these MAA analogues as new candidates to act as avobenzone-stabilizing compounds in addition to their UV absorbance and antioxidant properties, together with a facile synthesis.
阿伏苯宗是护肤配方中使用最广泛的防晒剂之一，但也存在一些缺点，包括光不稳定性。为了缓解这一关键问题，这些产品通常使用辛二烯作为稳定剂。然而，辛烯最近被证实具有潜在的光毒性。这项工作的目的是分析一系列受类菌体氨基酸（MAA）启发的化合物的性能，这些化合物可作为辛丙烯的替代品，用作阿伏苯宗稳定剂。在太阳模拟紫外线辐射剂量不断增加的情况下，对galenic配方中不同的阿伏苯宗/MAA类似物组合进行了跟踪研究。所分析的一些合成 MAA 类似物能够将阿维苯酮光漂白 50%所需的紫外线剂量提高两倍。我们建议将这些 MAA 类似物中的一些作为新的候选化合物，除了具有紫外线吸收和抗氧化特性外，还可作为阿维苯宗稳定化合物，并且合成简便。
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Pub Date : 2024-02-06DOI: 10.3390/photochem4010007
Jacobo Soilán, Leonardo López-Cóndor, Beatriz Peñín, José Aguilera, M. V. de Gálvez, Diego Sampedro, R. Losantos
Avobenzone is one of the most widely used sunscreens in skin care formulations, but suffers from some drawbacks, including photo instability. To mitigate this critical issue, the use of octocrylene as a stabilizer is a common approach in these products. However, octocrylene has been recently demonstrated to show potential phototoxicity. The aim of this work is to analyze the performance of a series of mycosporine-like amino acid (MAA)-inspired compounds to act as avobenzone stabilizers as an alternative to octocrylene. Different avobenzone/MAA analogue combinations included in galenic formulations were followed under increasing doses of solar-simulated UV radiation. Some of the synthetic MAA analogues analyzed were able to increase by up to two times the UV dose required for 50% of avobenzone photobleaching. We propose some of these MAA analogues as new candidates to act as avobenzone-stabilizing compounds in addition to their UV absorbance and antioxidant properties, together with a facile synthesis.
阿伏苯宗是护肤配方中使用最广泛的防晒剂之一，但也存在一些缺点，包括光不稳定性。为了缓解这一关键问题，这些产品通常使用辛二烯作为稳定剂。然而，辛烯最近被证实具有潜在的光毒性。这项工作的目的是分析一系列受类菌体氨基酸（MAA）启发的化合物的性能，这些化合物可作为辛丙烯的替代品，用作阿伏苯宗稳定剂。在太阳模拟紫外线辐射剂量不断增加的情况下，对galenic配方中不同的阿伏苯宗/MAA类似物组合进行了跟踪研究。所分析的一些合成 MAA 类似物能够将阿维苯酮光漂白 50%所需的紫外线剂量提高两倍。我们建议将这些 MAA 类似物中的一些作为新的候选化合物，除了具有紫外线吸收和抗氧化特性外，还可作为阿维苯宗稳定化合物，并且合成简便。
{"title":"Evaluation of MAA Analogues as Potential Candidates to Increase Photostability in Sunscreen Formulations","authors":"Jacobo Soilán, Leonardo López-Cóndor, Beatriz Peñín, José Aguilera, M. V. de Gálvez, Diego Sampedro, R. Losantos","doi":"10.3390/photochem4010007","DOIUrl":"https://doi.org/10.3390/photochem4010007","url":null,"abstract":"Avobenzone is one of the most widely used sunscreens in skin care formulations, but suffers from some drawbacks, including photo instability. To mitigate this critical issue, the use of octocrylene as a stabilizer is a common approach in these products. However, octocrylene has been recently demonstrated to show potential phototoxicity. The aim of this work is to analyze the performance of a series of mycosporine-like amino acid (MAA)-inspired compounds to act as avobenzone stabilizers as an alternative to octocrylene. Different avobenzone/MAA analogue combinations included in galenic formulations were followed under increasing doses of solar-simulated UV radiation. Some of the synthetic MAA analogues analyzed were able to increase by up to two times the UV dose required for 50% of avobenzone photobleaching. We propose some of these MAA analogues as new candidates to act as avobenzone-stabilizing compounds in addition to their UV absorbance and antioxidant properties, together with a facile synthesis.","PeriodicalId":74440,"journal":{"name":"Photochem","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139860673","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}
Pub Date : 2024-02-01DOI: 10.3390/photochem4010006
Valli Kamala Laxmi Ramya Chittoory, Marketa Filipsika, Radim Bartoš, M. Králová, P. Dzik
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.
{"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":"139880993","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}
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