Thiruvalluvar Government Arts College

The present study explores the synthesis and structural characterization of two novel organic photosensitizers. PBP-A and PBP-B, designed for DSSC applications. These sensitizers incorporate a thiophene core as a it-spacer, a phenyl-(benzo)phenothiazine moiety as the donor, and cyanoacrylic acid or rhodanine-3-acetic acid as the acceptor. The synthesized compounds' (PBP-A and PBP-B) molecular structure were characterized using UV-Vis, NMR and FT-IR spectroscopy. The dyes' photophysical properties have been examined using UV-Vis spectroscopy, photocurrent density measurements, incident photon-to-current efficiency (IPCE), cyclic voltammetry (CV), and electrochemical impedance spectroscopy. PBP-A and PBP-B dye-sensitized solar cells (DSSCs) had short-circuit current densities (Jsc) of 11.21 mA/cm-2 and 11.94 mA/cm-2, resulting in power conversion efficiencies (eta) of 5.63 % and 5.79 %, respectively. Furthermore, EIS analysis was used to assess the charge transfer characteristics at the electrode-electrolyte interface. The geometrical structures, optoelectronic properties, electron injection driving force (Delta Ginject), light-harvesting efficiency (LHE), excitation lifetime (tau), and other physicochemical characteristics were investigated using density functional theory (DFT) and time-dependent DFT (TD-DFT) computational approaches.

Industrial effluents containing synthetic dyes, particularly methylene blue (MB), pose severe ecological and life threats due to their chemical stability and toxicity. Advanced photocatalytic strategies offer promising solutions for dye remediation. In this study, a ternary graphitic carbon nitride (g-C3N4)/cobalt oxide/copper oxide (GCN/Co3O4/CuO) heterostructure was synthesized via a simple mechanical route to enhance visible-light-driven photocatalytic performance. The GCN/Co3O4/CuO heterostructure exhibited a reduced bandgap (2.19 eV) compared to pristine GCN (2.80 eV), facilitating efficient photoinduced charge carrier generation. Photocatalytic evaluation revealed that the ternary heterostructure degraded 95.4 % of MB within 120 min under visible-light irradiation, outperforming GCN (66.8 %), GCN/Co3O4 (70.3 %), and GCN/CuO (79.9 %). Kinetic analysis indicated a pseudo-first-order rate constant of 0.01975 min(-1), 2.78 times higher than that of pristine GCN. The optimal degradation efficiency was observed at 50 mg catalyst loading, 20 mg L-1 MB concentration, and neutral pH. Tapping experiments confirmed hydroxyl radicals (center dot OH) as the key active species, followed by photogenerated holes (h(+)) and superoxide radicals (center dot O-2(-)). The photocatalyst demonstrated excellent stability, retaining similar to 97 % activity after five consecutive cycles. Mechanistic studies suggested a dual Z-scheme charge transfer pathway, promoting effective electron-hole separation, prolonged carrier lifetimes, and enhanced redox activity. The synergistic interaction among GCN, Co3O4, and CuO broadens light absorption, increases active sites, and significantly improves photocatalytic efficiency. These findings highlight the GCN/Co3O4/CuO heterostructure as a highly efficient, stable, and reusable photocatalyst for the remediation of recalcitrant organic pollutants in aqueous systems.

The study presents the successful synthesis and crystallization of a square pyramidal copper(II) complex coordinated with glycine in its zwitterionic form [CuS_2(C_4H_10N_2O_4)]_2(C_2H_5NO_2)_2 (1), as confirmed by single crystal XRD study. The complex crystallizes in an orthorhombic system with space group Pna2_1 , exhibiting a tetracoordinated copper center bound to oxygen and sulfur atoms in a cis-square planar geometry. The crystal structure is stabilized by a comprehensive grid of hydrogen bonds involving N–H ⋯ O and N–H ⋯ S interactions, which form characteristic graph-set motifs and contribute to a three-dimensional zig-zag molecular packing. FTIR confirmed glycine coordination and Cu–N/Cu–S bonding. Thermogravimetric analysis reveals that the title compound is thermally stable up to 86 ^∘C , adequate for room-temperature lasing applications, and its subsequent decomposition further supports the elemental composition of the material. UV–Visible spectra showed a strong peak at 208 nm, an absorption edge at 237 nm, and a wide band gap of 5.55 eV, indicating high electronic stability. Photoluminescence revealed broad emission from 370 to 532 nm, deconvoluted into ligand-centered, ligand-to-metal, and metal-centered transitions, demonstrating efficient energy redistribution within the complex. Glycine, in its zwitterionic form, acts as a bidentate ligand coordinating with transition metals to form complexes exhibiting nonlinear optical behavior, including nonlinear absorption, refraction, and excited-state transitions through metal-ligand charge transfer. The nonlinear optical studies by Z-scan revealed self-defocusing behavior and efficient optical limiting. The measured nonlinear refractive index n_2 was 2.786× 10^-8 cm^2 W^-1 , and the nonlinear absorption coefficient β was 0.92× 10^-4 cm W^-1 . The third-order nonlinear optical susceptibility χ ^(3) was found to be 2.46× 10^-6 esu, demonstrating significant third-order nonlinear response. Optical limiting measurements showed an onset threshold of 1.545× 10^3 W cm^-2 proving the material’s ability to shield optical devices from high-intensity light.

Novel triazole amino acid derivatives (BTPC, CTPC, and NTPC) were synthesized in one-pot reactions and characterized with NMR, UV-Vis, and FT-IR spectroscopy. The synthesized compound chemical structure was optimized using the Density Functional Theory (DFT) B3LYP/6-311++G(d,p) basis set. The Multiwfn program was employed for topological studies such as ELF, LOL, ALIE, RDG, and ALIE (reactive sites of non-covalent interactions). The NBO analysis reveals inter and intra-molecular bond properties. The compounds' anti-proliferative activity was tested against MCF-7 and HepG2 human cancer cell lines using the MTT assay. Among the compounds evaluated, NTPC demonstrated the lowest IC50 values for both MCF-7 (4.92 +/- 0.78 mu M) and HepG2 (6.84 +/- 0.81 mu M) cell lines, signifying the most cytotoxic effectiveness. The antibacterial properties of the BTPC, CTPC, and NTPC compounds were tested against B. subtilis, S. aureus, E. coli, and P. aeruginosa. NTPC demonstrated the most significant antibacterial activity, with inhibition zones of 23.9 mm against S.aureus and 22.1 mm against B.subtilis. Molecular docking studies confirmed that BTPC has a higher binding affinity for both the breast cancer-associated estrogen receptor (PDB ID: 3ERT) and the liver cancer-associated EGFR kinase (PDB ID: 5UGB) than the other tested compounds CTPC, NTPC, and the reference drugs fluorouracil and sorafenib.

We fabricated a nanostructured thin film electrode composed of graphene oxide-supported, metal-doped oxide, incorporating conducting transition metals oxides of Mn-Cu-Co mixed oxides. The resulting GO-supported Mn/Cu-Co3O4 composite exhibits potential for energy storage applications utilizes the cost-effective, and suited preparative methodology, offering a promising platform for high-performance supercapacitors comprises the novel seed layer deposition strategy on the nickel (Ni) substrate. The structure and morphological traits CuCo2O4/GO (CCG), MnCo2O4/GO (MCG), and MnCuCo2O4/GO (MCCG) thin films were systematically acterized by using various physicochemical (FT-IR, SEM-EDX, XRD, and AFM techniques) and electrochemical investigations, which includes cyclic voltammetry (CV), charge-discharge (CHDH) efficiency and EIS reveals the intrinsic properties of modified mixed oxide base electrodes. Cyclic voltammetric analysis revealed that MCG, CCG, and MCCG thin film electrodes achieved specific capacitances of 450, 500, and 850 respectively, at a scan rate of 2 mV/s. In addition, their charge-discharge capacitance (CHDH) was found 600, 500, and 823 F g-1, highlighting the superior energy storage performance of the MCCG electrode. the other mixed oxide-based materials, MCCG based electrode exhibits stable specific capacitance over charge-discharge performance utilizes the excellent cyclic stability and long-term energy storage system. analysis investigates average specific capacitances of 500, 727, and 878 F g-1 for, the CCG, MCG, and electrodes, respectively. The proposed synthesis approach is environmentally friendly and cost-effective, a promising strategy for the development and large-scale manufacturing of next-generation energy devices.