B.M.S. Institute of Technology and Management

In the present work, a chemical polymerization route was employed to synthesize polyaniline (PANI) with tailored properties through strategic variations in dopants and surfactants. The structural evolution induced by these modifications was systematically tracked via powder X-ray diffraction (pXRD), and the crystallite size estimated from XRD analysis was found to vary in the range of 1.4–9.9 nm, confirming the nanocrystalline nature of the synthesized PANI samples. Morphological analyses using scanning electron microscopy (SEM) and revealed particle sizes in the range of 30–85 nm, indicating the formation of agglomerated nanostructures composed of smaller crystallites, while energy-dispersive x-ray spectroscopy (EDS) confirmed phase purity. Transmission electron microscopy (TEM) confirmed distinctive particle size, surface features, and polycrystalline nature and SEM analysis Fourier transform infrared (FTIR) and Raman spectroscopy were used to identify functional groups and probe the chemical structure, respectively. UV-Visible spectroscopy indicated direct and indirect bandgap energies in the ranges of 2.4–2.8 eV and 1.41–1.47 eV, respectively reflecting tunable optoelectronic characteristics. Thermal stability was analyzed by thermogravimetric analysis (TGA/DSC). The key finding of this work lies in establishing a clear correlation between specific dopant–surfactant combinations and enhanced electrical performance. Impedance analysis demonstrated that PANI doped with HCl, and PANI incorporating H₂SO₄ as a dopant with DBSA as a surfactant exhibited the highest electrical conductivity, depicting values of 1.58 × 10⁻⁴ S/cm and 4.09 × 10⁻⁴ S/cm, respectively. This systematic approach provides new insights into the design of highly conductive PANI-based materials for applications in sensors, flexible electronics, and energy storage devices.

In this study, heterojunction nanostructures S1-TiO2 and S2-TiO2/NiTiO3—were successfully synthesized via a microwave-assisted solution combustion technique. The heterojunction nanostructures were comprehensively characterized to assess their physicochemical properties relevant to photocatalysis. Structural and morphological analyses using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDAX), and Brunauer–Emmett–Teller (BET) surface area measurements confirmed the formation of well-crystallized materials. XRD results revealed an average crystallite size of approximately 30 nm. UV–Vis diffuse reflectance spectroscopy (UV-DRS) demonstrated a narrowed optical band gap of 2.69 eV for the S2-TiO2/NiTiO3 composite, indicative of enhanced visible-light absorption. SEM imaging showed a sheet-like NiTiO3 framework decorated with spherical TiO2 nanoparticles ranging from 20 to 50 nm. The S2−TiO2/NiTiO3 sample exhibited a significantly higher surface area (65.215 m2/g) compared to S1-TiO2, correlating with its superior photocatalytic performance. Photocatalytic experiments conducted under natural sunlight using Eriochrome Black T (EBT) and Methyl Red (MR) as model azo dyes confirmed the enhanced activity of the S2-TiO2/NiTiO3 heterostructure. These results establish the S2-TiO2/NiTiO3 composite as a highly effective and environmentally sustainable photocatalyst for the remediation of dye-contaminated water.

This study introduces green carbon fibers (GCF), a novel adsorbent material made from banana pseudostem for the purpose of environmentally friendly wastewater treatment. GCF effectively removes lead (Pb2+) from water by virtue of its high porosity, thermal stability, and surface activity. Distilled from agricultural byproducts, this material stands out from the ordinary activated carbons because to its ability to retain the original fiber shape and hierarchical pore patterns. The experimental conditions included a pH of 5.5, temperatures between 15 and 45℃, lead ion concentrations of 60 and 100 mg/L, and adsorbent doses ranging from 30 to 70 mg. Zeta potential studies, energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), and zeta potential all confirmed that the GCF structure was quite porous and that the surface chemistry was rather beneficial. With maximum capacity of 79.62 mg/g, adsorption kinetics pursued a pseudo-second-order (PSO) model, indicating chemisorption (R2 = 0.993). Due to heterogeneous multilayer adsorption, the Freundlich isotherm model yielded a R² value of 0.9343. With an R2 of 0.9676 and an MSE of 54.981, the MLP Regressor outperformed all other machine learning models, demonstrating that adsorbent weight is the most important factor, whereas the RSM model showed strong prediction reliability with a Reduced 2FI model. These results demonstrate that it is possible to convert agricultural waste into effective adsorbents, which would be a green and cost-effective way to remove heavy metals from wastewater.

We report on water splitting, disinfection, and pollutant degradation processes assisted by photocatalysis supported by zinc oxide (ZnO) under varied experimental and environmental conditions. In addition, the role of ozonation in the presence of ZnO and its synergistic impact on the effective elimination of organic and inorganic contaminants is discussed, highlighting enhanced reaction kinetics and mineralization efficiency. ZnO nanoparticles (ZnO-NPs) have also emerged as appropriate and versatile tools in drug delivery systems and chemical or biological sensing applications due to their biocompatibility, tunable surface chemistry, and strong photoluminescence response. Owing to its distinctive structural, optical, and electronic properties, ZnO has been extensively employed as an n-type inorganic semiconductor in organic solar cells (OSCs) and hybrid solar cells (HSCs), where it functions efficiently as an electron transport and hole-blocking layer. Its high chemical and thermal stability, non-toxicity, facile synthesis routes, low production cost, and excellent optoelectronic characteristics make ZnO highly attractive for large-scale technological applications. Furthermore, ZnO is widely used as a preservative and functional additive in numerous products and materials, including foundations, ceramics, glass, rubbers, lubricants, plastics, cement, ointments, paints, adhesives, sealants, colorants, ferrites, foods, batteries, food enhancers, fire-retardant systems, and first-aid tapes. These diverse applications underscore the multifunctional nature and industrial relevance of ZnO-based materials.

Polyvinyl alcohol (PVA) is a well-known packaging material; however, its major drawback is the lack of inherent antibacterial properties, which are essential for preventing food spoilage. In the present work, we developed a method to enhance the antibacterial properties of PVA thin films by incorporating nanoparticles (NPs) into the films. Undoped and cobalt (Co)-doped zinc oxide (ZnO) nanoparticles were synthesized using PVA as a capping agent. The nanoparticles were prepared via chemical precipitation and microwave-assisted methods, and characterized using UV-Visible spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and X-Ray Diffraction (XRD). The crystallite sizes of the undoped and Co-doped ZnO were found to be 30.6 nm and 22.9 nm, respectively. SEM imaging revealed variations in surface morphology with different concentrations of PVA capping. PVA thin films containing 0.1