Yazar "Dogan, Sifa" seçeneğine göre listele

Listeleniyor 1 - 7 / 7
  • [ X ]
    Öğe
    Asymmetric phthalocyanine-based hole-transporting materials: evaluating the role of heterocyclic units and PMMA additive
    (Royal Soc Chemistry, 2024) Dogan, Sifa; Unal, Muhittin; Demircioglu, Perihan Kubra; Molina, Desire; Ince, Mine; Akin, Seckin
    Two novel asymmetric phthalocyanine derivatives, ZnPc-1 and ZnPc-2, are synthesized to enhance charge transfer properties and mitigate deep-level traps on the perovskite surface using electron-rich nitrogen atoms. PSCs with ZnPc-1 and ZnPc-2 as hole-transporting materials (HTMs) achieved power conversion efficiencies (PCEs) of 12.11% and 8.98%, respectively. Incorporating a small amount of PMMA into the HTM solution significantly improved performance, resulting in PCEs of 16.2% and 12.5% for ZnPc-1 and ZnPc-2, respectively. The addition of PMMA enhances conductivity and prevents moisture intrusion, boosting both the efficiency and stability of PSCs. ZnPcs with pyridine or imidazole units were synthesized as HTMs in PSCs. PMMA addition improved performance and stability, reaching 16.2% PCE for ZnPc-1.
  • [ X ]
    Öğe
    Influence of bulky peripheral substituents on subphthalocyanine derivatives: Implications for photocatalytic and photoelectrochemical hydrogen production
    (Elsevier Sci Ltd, 2024) Dogan, Sifa; Guentay, Buket; Demircioglu, Perihan Kuebra; Akyrldrz, Yigit Osman; Koca, Ayse; Aslan, Emre; Kurtay, Guelbin
    A series of novel subphthalocyanine (SubPc) derivatives with bulky electron-donating substituents were synthesized for visible light-induced photocatalytic and photoelectrochemical hydrogen production. SubPc derivatives were decorated with bulky thiophenoxy (coded SubPc 1-2) and phenoxy (coded SubPc 3-4) substituents to compare the influence of the nature of the peripheral bulky substituents on the photophysical and photocatalytic activity of SubPc. The highest photocatalytic performance was obtained from SubPc 4, having diphenyl phenoxy substituents with an H-2 production rate of 7.233 mmol g(-1)h(-1). The photocatalytic hydrogen evolution activities of all SubPc sensitized TiO2 photocatalysts enhanced approximately four times in the presence of Pt co-catalyst. The photocatalysts showed remarkable long-term stability and reproducibility of H-2 evolution over 24-hour irradiation. SubPc 4-based photocatalytic system reached a considerable catalytic activity with the H-2 production of 16.022 mmol g(-1) and a turnover number (TON) value of 34,089 for 24 h irradiation. Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT) studies were carried out to better understand the photocatalytic abilities of SubPc derivatives and develop a symbiotic connection with experimental investigations. The results highlight the importance of peripheral substituents in modifying electron density, dipole moment, and HOMO-LUMO energy levels and improving SubPc derivative lightharvesting performance. The presence of 2,6-diisopropyl on SubPc derivatives (SubPc 2 and 4) caused a significant change in the properties, resulting in favourable electron transport characteristics and, therefore, improving photocatalytic performance. Furthermore, the incorporation of TiO2, as shown in SubPc 1@TiO2 and SubPc 2@TiO2, resulted in a modest reduction in chemical hardness, implying increased charge transfer inside the molecule and, as a consequence, enhancing its efficacy as a sensitizer. These theoretical discoveries provide a solid foundation for the customized design and optimization of SubPc derivatives for effective photocatalytic applications.
  • [ X ]
    Öğe
    Mitigating VOC Loss in Single-Junction and Four-Terminal Tandem Perovskite/Si Photovoltaics with D-A Phthalocyanines Layers
    (Wiley-V C H Verlag Gmbh, 2024) Li, Chi; Dogan, Sifa; Li, Yuheng; Zhang, Huifeng; Tang, Shicheng; Yuan, Zhen; Liang, Lusheng
    The performance of perovskite solar cells (PSCs) is often constrained by significant open-circuit voltage (V-OC) losses attributed to non-radiative recombination processes induced by detrimental trap states. Surface treatments using passivating ligands typically involve single active binding sites on perovskite, posing challenges for effective passivation. Here, an aromatic donor-acceptor (D-A) configured phthalocyanine treatment is proposed to aim at dual-site passivation of uncoordinated lead ions and effective mitigation of shallow and deep-level defects on the perovskite surface. The resulting benign p-type surface facilitates a more favorable energy level alignment and reduces energetic mismatches at the perovskite/Spiro-OMeTAD interface. Pc-BTBC, with its aromatic D-A configuration, demonstrated compatibility with various perovskite compositions. Optimized PSCs achieves a power conversion efficiency (PCE) of 25.15% and reduces the V-OC deficit to 0.379 V. Furthermore, encapsulated devices exhibited enhanced stability under damp-heat conditions (ISOS-D-2, 50% RH, 65 degrees C) with a T-92 of 1000 h and maintained maximum power point tracking under continuous light in ambient air at 65 degrees C (ISOS-L-2). Notably, fabricated wide-bandgap semitransparent PSCs (ST-PSCs) achieved a PCE of 20.29%, while four-terminal perovskite/silicon tandem solar cells (4T-P/STSCs) demonstrated an efficiency of 29.38%. This study provides insights into minimizing V-OC losses and represents significant progress toward commercializing perovskite photovoltaics.
  • [ X ]
    Öğe
    Photodynamic therapy potential of cobalt phthalocyanine in triple-negative breast cancer
    (Pergamon-Elsevier Science Ltd, 2023) Dogan, Sifa; Ince, Mine; Sogutlu, Fatma; Avci, Cigir Biray; Ozel, Derya; Yurt, Fatma
    Triple-negative breast cancer (TNBC) has the worst prognosis among breast cancers. The deficiency of hormone receptors (ER-/PR-/HER-2-) limits treatment options. Photodynamic therapy (PDT) is a safe treatment method for target-specific applications and has no toxic side effects. In this study, the efficacy of PDT on TNBC cells after activation of phthalocyanine derivative CoPc-COOH with RED light was investigated. The cytotoxicity of CoPc-COOH in MDA-MB-231 cells was evaluated at 24, 48, and 72 h. To detect phototoxic activity, cells were exposed simultaneously to a dose range of CoPc-COOH at 48th hours and 20, 30, 40, and 50 J/cm2 RED light in a laser source with an output fluorescence of 12 mW/cm2. The apoptotic effect of single CoPc-COOH, RED light, and their combinations were examined by using the Annexin V method and the ROS generation potential using the carboxy-H2-DCFH-DA test in flow cytometry. DCF fluorescence intensity of control and dose groups were taken under the fluorescence microscope. The IC50 values of CoPc-COOH in MDA-MB-231 cells at the 24th, 48th, and 72nd hours were calculated as 131.04 mu M, 66.75 mu M, and 59.74 mu M, respectively. In the phototoxicity test, 50 J/ cm2 application increased the IC50 dose of CoPc-COOH to 73.73 mu M; 20, 30, 40 J/cm2 application reduced the doses to 2.31 mu M, 0.20 mu M, and 28.14 mu M, respectively. Compared to the untreated group, it was determined that ROS formation and apoptotic stimulation were triggered significantly in treatment groups. A combination of CoPc-COOH and 40 J/cm2 showed the highest synergistic effect.
  • [ X ]
    Öğe
    Solar light-driven hydrogen evolution by co-catalyst-free subphthalocyanine-sensitized photocatalysts
    (Royal Soc Chemistry, 2024) Dogan, Sifa; Guntay, Buket; Demircioglu, Perihan Kubra; Akyildiz, Yigit Osman; Aydin, Hasan; Aslan, Emre; Can, Mustafa
    Subphthalocyanines (SubPcs) have emerged as promising organic dyes for the development of efficient artificial photosynthetic devices, offering intense absorption in the visible region along with excellent charge transport properties. In this study, four novel SubPc derivatives containing carboxylic acid and various peripheral substituents were synthesized as a panchromatic photosensitizer to prepare an efficient and stable TiO2-based photocatalytic system for co-catalyst-free photocatalytic hydrogen evolution. To compare the influence of the nature of the peripheral substituents on photocatalytic activity, SubPc derivatives (coded as SubPc 1-4) were decorated with substituents having different electron-donating capabilities, such as alkyl thio, benzodioxin, amine, and iodo units, respectively. Photocatalytic activities were examined in the presence of TEOA as a sacrificial agent under irradiation with lambda > 400 nm without co-catalyst loading. SubPc 1/TiO2 shows the best photocatalytic activity among the SubPc-sensitized photocatalysts, with a hydrogen evolution rate of 0.176 mmol h(-1). While the activity of all four SubPc-based photocatalysts increased significantly after 24 h irradiation, notably, SubPc 1/TiO2 exhibited remarkable catalytic activity, achieving a hydrogen evolution rate of 6.017 mmol with a high turnover number (TON) value of 12 279 for hydrogen production. This study highlights the potential of SubPc-based sensitizers for co-catalyst-free photocatalytic H-2 production and offers valuable insights into the impact of peripheral units in SubPc/TiO2-based photocatalytic systems.
  • [ X ]
    Öğe
    Subphthalocyanines for Visible-Light-Driven Hydrogen Evolution: Tuning Photocatalytic Performance with Molecular Design
    (Amer Chemical Soc, 2023) Guntay, Buket; Dogan, Sifa; Killi, Askin; Genc Acar, Eminegul; Demircioglu, Perihan Kubra; Aslan, Emre; Kurtay, Gulbin
    In this work, a series of subphthalocyanines (SubPcs)with a carboxylicacid anchoring group at the axial position were used as photosensitizersof TiO2 for photocatalytic hydrogen evolution from waterunder visible light irradiation. SubPc derivatives with various peripheralsubstituents were successfully prepared to systematically investigatethe dependence of photocatalytic performance on electron-donatingunits (i.e., bisthiophene or thioether) at the peripheral positionof the SubPcs. SubPc 2/TiO2/Pt shows the best photocatalyticactivity among the three dye-sensitized photocatalysts, with a hydrogenevolution rate of 1.104 mmol center dot g(-1)center dot h(-1). After 24 h irradiation, SubPc 2/TiO2/Ptachieved a remarkable catalytic activity for the production of H-2 (19.96 mmol center dot g(-1)) with a TON valueof 40 734 and a high STH efficiency of 2.1%. Density functionaltheory (DFT) and time-dependent DFT (TD-DFT) approaches were usedto elucidate further structural and electrical properties, includingthe interaction patterns of tailored SubPcs. It is worth noting thatthe theoretical computations exhibit good conformity with the empiricaldata. The predicted fluctuations in photocatalytic activity detectedin SubPc systems were shown to be closely associated with frontiermolecular orbital (FMO) characteristics, noncovalent interaction (NCI)patterns, and the electron-donating nature of the fragments locatedat the peripheral positions.
  • [ X ]
    Öğe
    Unveiling combat strategies against Candida spp. biofilm structures: Demonstration of photodynamic inactivation with innovative phthalocyanine derivatives
    (Elsevier Science Sa, 2024) Ozturk, Ismail; Ozel, Derya; Dogan, Sifa; Tuncel, Ayca; Yurt, Fatma; Tekintas, Yamac; Demircioglu, Perihan Kubra
    Antimicrobial resistance is an important problem for infection control and therapy. Microorganisms in biofilm structure are remarkably less susceptible to antimicrobials compared to planktonic cells. Increasing rates of resistance to antimicrobials have led to the development of new antimicrobial strategies. Antimicrobial photodynamic therapy (PDT) is an alternative treatment method that may contribute to the fields of infection control and treatment. This study aimed to investigate the antifungal activities of photosensitizers and the anti -biofilm activities of phthalocyanine derivatives on C. albicans and C. parapsilosis strains. The anti -biofilm effects of aPDT on the biofilm of Candida albicans were also visualized via SEM (Scanning Electron Microscopy). Our findings showed that aPDT with phthalocyanines inhibited biofilm production levels and reduced the mature biofilm levels of Candida strains. Additionally, SEM results supported that aPDT application successfully eradicated fungal cells and inhibited the biofilm produced by C. albicans . Although more detailed experiments are needed, we suggest that the use of Pcs in aPDT may be beneficial for the treatment of biofilm-related Candida infections.