Facile fabrication of novel Z-scheme g-C3N4 nanosheets/ Bi7O9I3 photocatalysts with highly rapid photodegradation of RhB under visible light irradiation.

A simple and economical hydrothermal method has efficiently been utilized in the fabrication of a novel C3N4 nanosheet/Bi7O9I3 Z-scheme heterojunction. The synthesis process was carried out under ordinary temperature and pressure without any poisonous ingredients. Different techniques, such as EDX, XRD, FESEM, FTIR, UV-Vis, DRS, PL, and BET, were employed to analyze the as-prepared nanocomposite. To evaluate the photocatalytic activity, degradation of several cationic and anionic organic dyes, i.e., Rhodamine B (RhB), Congo red (CR), and malachite green (MG), under visible light irradiation was investigated. Among the Synthesized binary nanocomposites, the g-C3N4 nanosheet/Bi7O9I3 (15%) demonstrated a superlative efficient photocatalytic performance toward photodegradation of the above-mentioned organic dyes. The results exhibited that 94% of Rhodamine B was decomposed within 20 min by the photodegradation process. These results are due to the reduction of the recombination rate of electron-hole pairs, broadening the visible light harvesting, and improving the photocatalytic yield of graphite carbon nitride. According to the presented data and results, a probable mechanism is suggested. Also, the OH radicals were determined as the main reactive species involved in the degradation reaction. This work presents a novel, recyclable, and high-efficiency Z-scheme heterostructure photocatalyst that may provide a more promising approach for environmental restoration.

Response surface methodology optimizing the adsorptive removal of azithromycin using mesoporous silica SBA-15: Mechanism, thermodynamic, equilibrium, and kinetics modeling studies.

The objective of this research was to study an effective adsorbent for removing azithromycin (AZT) from industrial wastewater. AZT is an antibiotic used for many diseases remedy, but it is a pollutant to our environment; therefore, its residual should be removed from wastewater. The mesoporous SBA-15 silica as an efficient adsorbent was prepared by the hydrothermal method. The surface of mesoporous SBA-15 plays a significant role in the removal process; therefore, the characterization of the adsorbent was accomplished by several techniques. The batch system has been used, and the effect of four essential variables: pH (3-10), drug concentration (20-200 mg L-1), sorbent weight (0.2-2 g L-1), and temperature (20-40 °C) were investigated on the AZT removal efficiency by response surface methodology (RSM). The isotherm results were found to be in proper compliance with the isotherm model of Freundlich. In the kinetics part of this study, the experimental outcomes were fitted to the equation model of pseudo-second-order. The calculation of thermodynamic parameters shows that the removal process is spontaneous and endothermic. Upon the results, the vast surface area, the active functional groups, reusability, stability, and inexpensively make the mesoporous SBA-15 a suitable candidate for removal of AZT and similar antibiotics.