Graphitic carbon nitride (g-C3N4) has emerged as a promising visible-light-responsive photocatalyst for wastewater treatment. However, its practical application is hindered by limited visible-light absorption and the rapid recombination of photogenerated charge carriers. In the present study, a cerium-modified graphitic carbon nitride composite (Ce-g-C3N4) was synthesized through a hydrothermal route to improve the photocatalytic degradation of Rhodamine B (RhB) under visible-light irradiation. The structural, morphological, and optical properties of the prepared materials were investigated using XRD, FTIR, UV-Vis spectroscopy, and SEM-EDS analyses. UV-Vis analysis revealed a reduced band gap energy of 2.59 eV for Ce-g-C3N4, indicating enhanced visible-light absorption compared with pristine g-C3N4. SEM observations showed a fragmented sheet-like morphology with a rough surface texture, which is favourable for dye adsorption and photocatalytic reactions. The effects of catalyst dosage, initial dye concentration, solution pH, and irradiation time on RhB degradation were systematically evaluated. Under the optimized conditions of 30 mg catalyst dosage, 50 ppm RhB concentration, and pH 9.5, the Ce-g-C3N4 composite achieved a maximum degradation efficiency of 89.1% within 70 min, whereas pristine g-C₃N₄ exhibited only 69.7% degradation under identical conditions. The degradation process followed pseudo-first-order kinetics with an apparent rate constant of 0.0324 min⁻¹ and a correlation coefficient (R2) of 0.9897. In addition, the photocatalyst retained 81.2% of its initial activity after five consecutive cycles, demonstrating good stability and reusability. The improved photocatalytic performance is attributed to the modification of the electronic structure and enhanced visible-light utilization induced by cerium incorporation. These findings demonstrate that Ce-g-C3N4 is an efficient and stable visible-light-responsive photocatalyst with potential applications for treating dye-contaminated wastewater.
The increasing demand for sustainable polymer processing requires the replacement of conventional toxic solvents. However, limited information is available on how environmentally friendly solvents, particularly ethyl acetate (EA) as a sustainable alternative to chloroform (H), influence the structural, morphological, surface, and optical properties of spincoated poly(ε-caprolactone) (PCL) thin films. In this study, the effect of solvent selection on the properties of PCL thin films prepared by spin coating was investigated, highlighting the potential of EA as a more environmentally friendly alternative for PCL film fabrication. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), contact angle measurements, and UV–Vis spectroscopy. XRD analysis confirmed the preservation of the orthorhombic crystalline structure of PCL, with similar crystallite size values indicating that the choice of solvent had no significant effect on the crystallization process or the size of the crystalline domains. SEM analysis showed that both films have a characteristic spherulite morphology, with the PCL-EA film forming larger spherulites than the PCL-H film. At the same time, the PCLEA film exhibited a higher surface free energy and a more pronounced polar component, with a measured surface free energy of 54.70 mN/m compared with 41.62 mN/m for the PCL-H film, indicating better wettability and more favorable interfacial interactions. UV–Vis analysis showed higher optical band gap values for both direct and indirect electronic transitions in the PCL-EA film compared to the PCL-H film, with direct and indirect band gap values of 5.0 eV and 4.8 eV for PCL-EA, and 4.8 eV and 4.1 eV for PCL-H, respectively, which may indicate a reduced number of localized energy states and greater structural order, with both films retaining the optical properties characteristic of PCL as an electrically insulating polymer. The results confirm that ethyl acetate is a suitable, more sustainable alternative to chloroform for preparing PCL thin films, thereby improving surface and optical properties while preserving the structural characteristics of the biodegradable polymer. Such thin films have potential applications in sustainable polymer coatings, packaging materials, and other environmentally friendly technologies, contributing to the development of greener polymer fabrication approaches.
Zirconium dioxide (ZrO₂) nanoparticles were synthesized from zirconyl chloride octahydrate using Toddalia asiatica leaf extract through an environmentally sustainable route and evaluated for Congo Red (CR) adsorption. XRD, FTIR, SEM–EDX, TGA, and XRF analyses confirmed the crystalline structure, morphology, surface functional groups, elemental composition, and thermal stability of the synthesized nanoparticles. Adsorption performance was investigated using an integrated Taguchi–ANOVA–PSI–PIV–CFANN framework. ANOVA revealed that ZrO₂ dosage predominantly influenced CR removal, whereas initial concentration and dosage governed adsorption capacity. PSI–PIV identified Run 27 at 75 mg L⁻¹ CR, 90 min, 40 °C and 0.25 g L⁻¹ ZrO₂ as the best experimental compromise, achieving 63.56% removal efficiency and the experimentally calculated adsorption capacity. CFANN–PSI–PIV predicted an optimum at 75 mg L⁻¹, 90 min, 50 °C, and 0.25 g L⁻¹, with 67.2169% removal efficiency and the corresponding predicted adsorption capacity. The latter condition represents a model-predicted optimum. These findings demonstrate that green-synthesized ZrO₂ nanoparticles, combined with data-driven optimization, offer a promising approach for treating CR-contaminated wastewater.
The present study investigated the green synthesis of zinc–iron–copper oxide (ZFCO) nanoparticles using Ocimum tenuiflorum leaf extract for the photocatalytic degradation of Fast Green (FG) dye. Despite advances in green-synthesized ferrite photocatalysts, limited attention has been given to integrating Cu-modified ZFCO nanocatalysts with statistical optimization and machine-learning (ML) prediction for dye-contaminated wastewater treatment. Response Surface Methodology (RSM) based on a Central Composite Rotatable Design (CCRD 2³) was employed to evaluate the effects of dye concentration, catalyst dosage, and solution pH. ML was incorporated to capture nonlinear relationships among operating variables and provide reliable performance prediction beyond conventional statistical optimization. Gaussian Process Regression (GPR), Support Vector Regression (SVR), Ensemble Regression, and Random Forest (RF) models were evaluated, with GPR providing the highest predictive accuracy. Structural, surface, morphological, and optical characterization confirmed the successful formation of visible-light-responsive ZFCO nanostructures. Copper modification substantially enhanced photocatalytic performance compared with unmodified ZFCO, while RSM identified acidic conditions and appropriate catalyst loading as favorable for FG removal. The optimized experimental condition achieved 57.2% degradation, and Among the evaluated machine-learning models, SVR exhibited the best condition-wise nested cross-validation performance, achieving an R² of 0.9156, RMSE of 4.2915 and MAE of 2.9627. Overall, the integration of green synthesis, RSM optimization, and ML prediction provides a promising framework for developing and optimizing photocatalytic systems for practical treatment of dye-containing industrial wastewater.
Developing environmentally friendly Carbon nanoparticles (CNPs) using medicinal plants with enhanced biological activity has emerged as a strategy for the synthesize the nanomaterials for biomedical applications. This study aimed to evaluate the biogenic synthesis of carbon nanoparticles (CNPs) using Manilkara zapota leaf extract and their structural characteristics and biomedical potential. The synthesized nanoparticles were characterized using SEM, TEM, XRD, and FTIR analyses. Their antioxidant, anti-inflammatory inhibition, antibacterial activity, and cytotoxicity were evaluated using in vitro assays. SEM and TEM findings supported the formation of spherical nanoparticles, while XRD revealed the amorphous structure. FTIR identified the existence of functional groups such as OH, COOH, and NH, which aid in nanoparticle stabilization. The CNPs exhibited maximum antioxidant and anti-inflammatory potential at 50µg/mL, exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus with inhibition zones ranging from 9- 12 mm, and low dose-dependent cytotoxicity. The present study introduces the biosynthesized Carbon nanoparticles (CNPs) using Manilkara zapota leaf extract, which possess significant biomedical potential. The novelty of this study lies in the sustainable plant–mediated synthesis from Manilkara zapota leaf extract for Carbon nanoparticles (CNPs) with promising therapeutic potential. Further investigations are needed to evaluate their therapeutic application in wound-healing efficacy through in vitro and in vivo studies.
