aCoconut coir, an agricultural waste, was chemically modified using esterification by fatty acid chloride (oleoyl chloride and octanoate chloride) for oil spill removal purposes. The modified coir (coir-oleate and coir-octanoate) were characterized by spectroscopy, thermal studies, contact angle, and morphological studies. The modified coir exhibited an enhancement towards the hydrophobic property but a decreased thermal stability. The oil adsorption performance was tested using a batch adsorption system. The effect of sorbent dosage, oil concentration, and effect of adsorption time on the adsorption capacity of the modified coir were also studied. From the analysis, the long chain oleoyl chloride (C18) was shown to be a better modifier compared to octanoate chloride (C8). The isotherm study indicated that the oil adsorption fitted well to a Langmuir model rather than Freundlich model. From the kinetic study, the result revealed a good fit in pseudo-second order model for all samples studied. The study therefore suggests that esterified coconut coir can serve as a potential biomaterial for the adsorption of spilled oil during operational failures.

No abstract

In this work, the photocatalytic performance of Ag3PO4, Nb2O5 and Ag3PO4/Nb2O5 hybrid photocatalysts to degrade methyl orange dye, MO, in an aqueous solution under visible light irradiation was evaluated. The Ag3PO4 and Ag3PO4/Nb2O5 photocatalysts, with various Ag to Nb molar ratios, were prepared using a facile precipitation method. The photocatalysts were characterized by X-ray diffraction, UV–Visible, X-ray Photoelectron, and Photoluminescence spectroscopies. Upon the addition of Ag3PO4, the band gap energy of Nb2O5 decreased from 3.0 eV to 2.7 eV, indicating the possible use of the Ag3PO4/Nb2O5 hybrid photocatalysts under visible light irradiation. All of the prepared Ag3PO4/Nb2O5 catalysts exhibited higher photocatalytic performance than Ag3PO4 in degrading methyl orange dye under 23-watt visible light irradiation. The Ag3PO4/Nb2O5 catalyst, with a mole ratio of 2:1, exhibited the fastest MO degradation rate of 7.3 × 10−2 min−1, which is twice faster than that of Ag3PO4. The catalyst also shows better stability, as it is reusable for up to six experimental cycles while maintaining its photocatalytic activity above 60%.

In the present study, we explored the effectiveness of PES-Ag3PO4/g-C3N4 film photocatalyst in degrading methyl orange dye under visible light irradiation. The PES-Ag3PO4/g-C3N4 film photocatalyst was prepared via a non-solvent-induced phase inversion process and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), laser scanning microscopy (LSM), X-ray photoelectron spectra (XPS), UV-diffuse reflectance (DRS), and water contact angle. The incorporation of the Ag3PO4/g-C3N4 composite into the PES matrix improved the pristine PES film’s hydrophilicity, as evidenced by the reduction of water contact angle from 79.03° to 54.33° for a film containing 15 wt % of Ag3PO4/g-C3N4 composite. The film’s photoactivity showed that 13 wt % was the best loading of Ag3PO4/g-C3N4 composite, and the degradation performance was maintained up to three cycles. The •O2− and h+ were the predominant species responsible for the methyl orange degradation.

No abstract