Oxidative desulfurization of dibenzothiophene over highly dispersed Mo-doped graphitic carbon nitride

Sustainable oxidative desulfurization of fuel via lignin-derived heterogeneous catalysis: Optimized by Box-Behnken design for high efficiency under mild conditions

This study evaluates the oxidative desulfurization of dibenzothiophene (DBT) in model fuel using Kraft lignin-functionalized sulfur-doped graphitic carbon nitride (KL@S-g-C3N4), an eco-friendly heterogeneous photocatalyst. The photocatalyst's formation was confirmed through Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, photoluminescence (PL), UV-visible spectroscopy, X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA) analyses, Brunauer-Emmett-Teller (BET), field revealing successful adsorption of Kraft lignin onto S-g-C3N4. The functional groups of lignin enhanced interfacial interactions, active site availability, and dispersion of S-g-C3N4, while synergistic effects improved optical absorption and catalytic reactivity. Process optimization via Box-Behnken design (BBD) identified catalyst dosage (0.05 g), reaction time (37.5 min), and temperature (40 °C) as optimal parameters, achieving 98.1 % sulfur removal (200 ppm initial concentration) with 1 mL H2O2. Statistical validation through ANOVA confirmed the quadratic model's reliability (R2 = 0.98) and non-significant lack of fit (p = 0.95). The photocatalyst retained structural integrity and performance over five reuse cycles, demonstrating robust durability. These findings position KL@S-g-C3N4 as a sustainable, efficient photocatalyst for desulfurization processes, combining enhanced catalytic activity with environmental compatibility.

Enriched photocatalytic and photoelectrochemical activities of a 2D/0D g-C3N4/CeO2 nanostructure

Sunlight-powered photocatalysts made from CeO2 nanosized particles and g-C3N4 nanostructures were produced through a thermal decomposition process with urea and cerium nitrate hexahydrate. The preparation of g-C3N4, CeO2, and a binary nanostructured g-C3N4/CeO2 photocatalyst was done through a facile thermal decomposition method. The structural properties were analyzed using powder X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy (XPS). Photocatalyst properties were characterized by using crystal violet (CV), a UV-Vis spectrophotometer, photocurrent and electron impedance spectroscopy (EIS). The structural and morphological analyses revealed that the g-C3N4/CeO2 nanostructures significantly enhanced the photoactivity for CV dye degradation under simulated sunlight, with a degradation rate of 94.5% after 105 min, compared to 82.5% for pure g-C3N4 and 45% for pure CeO2. This improvement was attributed to the noticeable visible light absorption and remarkable charge separation abilities of the nanostructures. Additionally, the g-C3N4/CeO2 nanostructures showed notable PEC performance under simulated sunlight. This study presents an easy and efficient method for producing g-C3N4 photocatalysts decorated with semiconductor materials and provides insights for designing nanostructures for photocatalytic and energy applications.