Ultrasonic-assisted synthesis of CaCu3Ti4O12/reduced graphene oxide composites for enhanced photocatalytic degradation of pharmaceutical products: Ibuprofen and Ciprofloxacin.

The objective of this research is to create a highly effective approach for eliminating pollutants from the environment through the process of photocatalytic degradation. The study centers around the production of composites consisting of CaCu3Ti4O12 (CCTO) and reduced graphene oxide (rGO) using an ultrasonic-assisted method, with a focus on their capacity to degrade ibuprofen (IBF) and ciprofloxacin (CIP) via photodegradation. The impact of rGO on the structure, morphology, and optical properties of CCTO was inspected using XRD, FTIR, Raman, FESEM, XPS, BET, and UV-Vis. Morphology characterization showed that rGO particles were dispersed within the CCTO matrix without any specific chemical interaction between CCTO and C in the rGO. The BET analysis revealed that with increasing the amount of rGO in the composite, the specific surface area significantly increased compared to the CCTO standalone. Besides, increasing rGO resulted in a reduction in the optical bandgap energy to around 2.09 eV, makes it highly promising photocatalyst for environmental applications. The photodegradation of IBF and CIP was monitored using visible light irradiation. The results revealed that both components were degraded above 97% after 60 min. The photocatalyst showed an excellent reusability performance with a slight decrease after five runs to 93% photodegradation efficiency.

Efficient removal of cationic dye using ZIF-8 based sodium alginate composite beads: Performance evaluation in batch and column systems.

The environmental and health risks associated with dye contamination in water sources are alarming. Recently, researchers have been focusing on developing an innovative and susceptible solution using composite beads that effectively combat this issue. In this paper, beads were synthesized using a sodium alginate (SA) and zeolitic imidazolate framework-8 (ZIF-8) through a simple dipping process. Several characterization tests were performed including XRD, FTIR, BET, TGA, and SEM-EDX. The SEM images confirmed that SA effectively coated the cubical structure of the ZIF-8, ensuring optimal performance. The efficiency of the resulting SA@ZIF-8 composite beads was tested on both synthetic malachite green dye and real industrial wastewater samples using batch and fixed bed column reactors. The findings revealed that maximum adsorption of 95.5% was achieved at pH 6 in 120 min of reaction time. FTIR and SEM analysis also confirmed the adsorption of MG dye onto the beads. The Freundlich isotherm model (R2 > 0.99) has a better fit than the Langmuir (R2 > 0.96) for describing the adsorption process. The PSO model predicted the kinetics of the system, whereas the intraparticle diffusion study supported the system's mechanistic analysis. Furthermore, the study also investigated the efficacy of the beads in treating real wastewater effluent samples collected from the dye industry. Overall, using sodium alginate-coated ZIF-8 beads was found to have many advantages over powdered ZIF-8, including higher selectivity, stability, reusability, and practicality, making them a promising alternative for adsorption applications. Therefore, these composite beads have the potential for the removal of the dye from wastewater, which could be widely applied in various industries.

Recent advances in Metal-Organic Frameworks as nanocarriers for triggered release of anticancer drugs: Brief history, biomedical applications, challenges and future perspective.

Metal-Organic Frameworks (MOFs) have emerged as a promising biomedical material due to its unique features such as high surface area, pore volume, variable pore size, flexible functional groups, and excellent efficiency for drug loading. In this review, we explored the use of novel and smart metal organic frameworks as drug delivery vehicles to discover a safer and more controlled mode of drug release aiming to minimize their side effects. Here, we systematically discussed the background of MOFs following a thorough review on structural and physical properties of MOFs, their synthesis techniques, and the important characteristics to establish a strong foundation for future research. Furthermore, the current status on the potential applications of MOF-based stimuli-responsive drug delivery systems, including pH-, ion-, temperature-, light-, and multiple responsive systems for the delivery of anticancer drugs has also been presented. Lastly, we discuss the prospects and challenges in implementation of MOF-based materials in the drug delivery. Therefore, this review will help researchers working in the relevant fields to enhance their understanding of MOFs for encapsulation of various drugs as well as their stimuli responsive mechanism.

Eliminating pesticide quinalphos from surface waters using synthesized GO-ZnO nanoflowers: Characterization, degradation pathways and kinetic study.

The presence of highly toxic and persistent pesticides in water bodies causes serious problems to human beings as well as aquatic life. Quinalphos is one such widely used organophosphorus pesticide in agricultural fields. Herein, for degradation and mineralization of quinalphos, ZnO nanoflowers and their hybrid nanocomposite with graphene oxide have been synthesized. FESEM analysis confirmed the formation of ZnO nanoflowers over nanosheets of graphene oxide having a thickness of 20 ± 10 nm. GO-ZnO composite exhibited remarkable photocatalytic activity in comparison to pure ZnO. 98 % degradation of quinalphos was achieved using GO-ZnO nano-catalyst at 6 pH within 45 min of irradiations, whereas it was 80 % for bare ZnO nanoflowers. Higher degradation with hybrid nanocomposite was attributed to improved surface area (36 m2 g-1), a substantial reduction in bandgap energy from 3.10 to 2.90 eV and enhanced charge separation (e-/h+ pairs) after the addition of GO. Reaction kinetics study followed pseudo-first-order behaviour. Further, mineralization to the extent of 90 % in 90 min was confirmed by TOC analysis. Based on identified intermediates, using LCMS analysis, degradation pathways were proposed. The plausible pathways confirmed the presence of smaller and safer reaction intermediates supported by excitation of e- from nanocomposite followed by oxidation of quinalphos with huge free radicals. Overall, this study is significant in terms of using photocatalysis as a tertiary treatment of quinalphos pesticide wastewater at pH 6 in a short duration.

Characterization and performance evaluation of synthesized ZnO nanoflowers, nanorods, and their hybrid nanocomposites with graphene oxide for degradation of Orange G.

Nanoflowers and nanorods of ZnO were synthesized via hydrothermal route. These morphologies of zinc oxide (ZnO) were then decorated over graphene oxide (GO) to yield hybrid nanocomposites, namely, GO-ZnOnR and GO-ZnOnF. The decoration of ZnO nanorods and nanoflowers on GO layers was confirmed through FESEM images. The synthesized nanocomposites were subjected to degrade the Orange G under identical conditions. The band gap energies determined using diffused reflectance spectra were 2.87, 2.89 eV for GO-ZnOnR, and GO-ZnOnF, whereas, for both ZnOnR and ZnOnF, it was 3.14 eV. For 50 min of UV irradiations (at 6 pH), 100% degradation was achieved corresponding to GO-ZnOnR (44.1 m2 g-1) followed by 90.1%, 70.2%, and 68.3% with GO-ZnOnF (35.9 m2 g-1), ZnOnR (20 m2 g-1), and ZnOnF (15.1 m2 g-1), respectively. Significant boost in the degradation of Orange G, with GO-ZnOnR, was attributed to its reduced band gap, higher surface area, and enhanced charge separation. Kinetic study confirms the pseudo-first-order reaction rate. Mineralization efficiency of 91% in 120 min indicated the efficient reduction of Orange G and its intermediates. Further, reactive species trapping experiments revealed that photo-induced •OH are dominant radicals for the degradation followed by •O2- and h+. Liquid chromatography mass spectra data has been used to predict the plausible reaction pathways. Reusability studies indicated that GO-ZnOnR can be used for four successive degradation cycles, without any significant activity loss.