This report investigates the elimination of hazardous Rhodamine B dye (RhB) from an aqueous medium utilizing MgTiO₃@g-C₃N₄ nanohybrids manufactured using a facile method. The nanohybrid MgTiO₃@g-C₃N₄ was generated using an ultrasonic approach in the alcoholic solvent. Various techniques, including HRTEM, EDX, XRD, BET, and FTIR, were employed to describe the fabricated MgTiO3@g-C3N4 nanohybrids. RhB elimination was investigated utilizing batch mode studies, and the maximum removal was attained at pH 7.0. The RhB adsorption process is more consistent with the Langmuir isotherm model. The highest adsorption capacity of MgTiO₃@g-C₃N₄ nanohybrids for RhB was determined to be 232 mg/g. The dye adsorption followed a pseudo-second-order model, and the parameters calculated indicated that the kinetic adsorption process was spontaneous. Using ethanol and water, the reusability of the nanomaterial was investigated, and based on the results; it can be concluded that the MgTiO₃@g-C₃N₄ nanohybrids are easily regenerated for dye removal. The removal mechanism for the removal of RhB dye into MgTiO₃@g-C₃N₄ nanohybrids was also investigated.

Bismuth oxyiodide (BiOI) is a targeted material for its relative safety and photocatalytic activity under visible light. In this study, a successful simple and energy-saving route was applied to prepare BiOI through a sonochemical process at room temperature. The characterization of the prepared BiOI was conducted by physical means. The transmission electron microscope (TEM) image showed that the BiOI comprises nanoparticles of about 20 nm. Also, the surface area of the BiOI was found to be 34.03 m² g⁻¹ with an energy gap of 1.835 eV. The adsorption and photocatalytic capacities of the BiOI were examined for the indigo carmine dye (IC) as a model water-pollutant via the batch experiment methodology. The solution parameters were optimized, including pH, contact time, IC concentration, and temperature. Worth mentioning that an adsorption capacity of 185 mg·g⁻¹ was obtained from 100 mg L⁻¹ IC solution at 25 °C within 60 min as an equilibrium time. In addition, the BiOI showed a high degradation efficiency towards IC under tungsten lamb (80 W), where 93% was removed within 180 min, and the complete degradation was accomplished in 240 min. The fabricated BiOI nanoparticles completely mineralized the IC under artificial visible light, as indicated by the total organic carbon analysis.

Continuous waste discharge into natural water resources in many countries is a severe global issue, and seeking an effective solution is a researcher’s concern. Herein, toilet paper waste was a low-cost precursor for preparing carbon nanoparticles (TPCNPs). The characterization of TPCNPs revealed a 30 nm to 50 nm particle size, a 264 m² g⁻¹ surface area, and a cubical graphite lattice XRD pattern. The TPCNPs were tested for removing malachite green (MG), indigo carmine (IC), rhodamine B (RB), and methylene blue (MB) dyes from water. The solution parameters were examined for the sorption process, and a pH of 5.0 suited the MB removal, while a pH of 6.0 was suitable for MG, IC, and RB. The effect of concentration investigation showed an adsorption capacity of 110.9, 64.8, 73.5, and 98 mg g⁻¹ for MG, IC, RB, and MB, respectively. The sorption of the four dyes fitted the Langmuir isotherm model; it was exothermic and spontaneous. The water remediation was tested using groundwater and seawater samples (GW and SW) spiked with pollutants. It is worth mentioning that one treatment sufficed for the remediation of GW and SW contaminated by 5 mg L⁻¹ concentration, while a double treatment was required for 10 mg L⁻¹ pollution in both samples.

In this study, a V@TiO₂ nanocomposite is examined for its ability to eliminate carcinogenic Rhodamine (Rh-B) dye from an aqueous medium. A simple ultrasonic method was used to produce the nanosorbent. In addition, V@TiO₂ was characterized using various techniques, including XRD, HRTEM, XPS, and FTIR. Batch mode studies were used to study the removal of Rh-B dye. In the presence of pH 9, the V@TiO₂ nanocomposite was able to remove Rh-B dye to its maximum extent. A correlation regression of 0.95 indicated that the Langmuir model was a better fit for dye adsorption. Moreover, the maximum adsorption capacity of the V@TiO₂ nanocomposite was determined to be 158.8 mg/g. According to the thermodynamic parameters, dye adsorption followed a pseudo-first-order model. Based on the results of the study, a V@TiO₂ nanocomposite can be reused for dye removal using ethanol.

A facile method was adopted to fabricate β-C₃N₄, and it was then doped with manganese and tellurium to obtain novel 10%MnTeO₃@β-C₃N₄ (10%MnTe@β) and 20%MnTeO₃@β-C₃N₄ (20%MnTe@β) nanohybrids. The β-C₃N₄, 10%MnTe@β, and 20%MnTe@β showed surface areas of 85.86, 97.40, and 109.54 m² g⁻¹, respectively. Using ciprofloxacin (CIP) as a pollutant example, 10%MnTe@β and 20%MnTe@β attained equilibrium at 60 and 45 min with q_t values of 48.88 and 77.41 mg g⁻¹, respectively, and both performed better at pH = 6.0. The kinetic studies revealed a better agreement with the pseudo-second-order model for CIP sorption on 10%MnTe@β and 20%MnTe@β, indicating that the sorption was controlled by a liquid film mechanism, which suggests a high affinity of CIP toward 10%MnTe@β and 20%MnTe@β. The sorption equilibria outputs indicated better alignment with the Freundlich and Langmuir models for CIP removal by 10%MnTe@β and 20%MnTe@β, respectively. The thermodynamic analysis revealed that CIP removal by 10%MnTe@β and 20%MnTe@β was exothermic, which turned more spontaneous as the temperature decreased. Applying 20%MnTe@β as the best sorbent to groundwater and seawater spiked with CIP resulted in average efficiencies of 94.8% and 91.08%, respectively. The 20%MnTe@β regeneration–reusability average efficiency was 95.14% within four cycles, which might nominate 20%MnTe@β as an efficient and economically viable sorbent for remediating CIP-contaminated water.