Immobilized BiOCl0.75I0.25/g-C3N4 nanocomposites for photocatalytic degradation of bisphenol A in the presence of effluent organic matter

The BiOCl_0.75I_0.25/g-C₃N₄ nanosheet (BCI-CN) was successfully immobilized on polyolefin polyester fiber (PPF) through the hydrothermal method. The novel immobilized BiOCl_0.75I_0.25/g-C₃N₄ nanocomposites (BCI-CN-PPF) were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy EDS, X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-vis diffuse reflectance spectroscopy (UV-vis DRS) to confirm that BCI-CN was successfully immobilized on PPF with abundant oxygen vacancies reserved. Under simulated solar light irradiation, 100 % of bisphenol A (BPA) with an initial concentration of 10 mg·L^-1 was degraded by BCI-CN-PPF (0.2 g·L^-1 of BCI-CN immobilized) after 60 min. A similar photocatalytic efficiency of BPA was obtained in the presence of effluent organic matter (EfOM). The photocatalytic degradation of BPA was not affected by EfOM <5 mg-C/L. In comparison, the photocatalytic performance was considerably inhibited by EfOM with a concentration of 10 mg-C/L. Furthermore, photogenerated holes and superoxide radicals predominated in the photocatalytic degradation processes of BPA. The total organic carbon (TOC) removal efficiencies of BPA and EfOM were 75.2 % and 50 % in the BCI-CN-PPF catalytic system. The BPA removal efficiency of 94.9 % was still achieved in the eighth cycle of repeated use. This study provides a promising immobilized nanocomposite with high photocatalytic activity and excellent recyclability and reusability for practical application in wastewater treatment.

A novel visible light active rare earth doped CdS nanoparticles decorated reduced graphene oxide sheets for the degradation of cationic dye from wastewater

A variety of rare earth metals (La, Sm, Nd, Ce, Gd) doped cadmium sulfide (RE-CdS) grafted reduced graphene oxide (G) sheet nanocomposites estimated imperative attention due to their visible light-driven, tunable band gap and high surface to volume ratio were investigated for the photocatalytic degradation of cationic dye from aqueous solution. The formation of wurtzite (hexagonal) crystal structures of cadmium sulfide nanoparticles (NPs) was confirmed by Powder X-ray diffraction spectra and the average crystallite size was determined to be 10 ± 2 nm. HRTEM analysis confirmed the homogeneous distribution of RE-CdS NPs over the G sheets. The photocatalytic behaviour of the RE-CdS decorated G sheets was studied using a textile dye methylene blue (MB) under sunlight. The result indicates that among the various RE-CdS nanocomposites studied, Cerium-cadmium sulfide-reduced graphene oxide (Ce-CdS-G) shows highest MB degradation of 99.0 ± 0.4% within 90 min under sunlight. The result confirms that RE-CdS-G nanocatalyst efficiently accelerates the separation and slows down the recombination rate in photo excited charge carriers. The catalytic activity was retained over 80% of its original value even after four successive runs and the present method can be employed for the large-scale synthesis of RE-CdS-G nanocatalyst.