Photocatalytic investigation of textile dyes and E. coli bacteria from wastewater using Fe3O4@MnO2 heterojunction and investigation for hydrogen generation on NaBH4 hydrolysis.

Various impurities found nowadays in water can be detrimental to human health. This work focused on utilizing Fe3O4@MnO2 nanocomposite for cleaning organic contaminants from water, including rhodamine B (RhB) and Escherichia coli (E. coli). Analysis methods such as XRD, UV-vis, TEM, and FTIR were used to describe the nanocomposite. The results showed that the developed nanocomposite has good photocatalytic activity against pollutants in wastewater. The E. coli was destroyed after 90 min, and the RhB photodegradation rate was 75%. Moreover, the Fe3O4@MnO2 efficiency as a catalyst for producing hydrogen as an alternative energy source was tested. According to the calculations, the nanomaterial's turnover frequency, activation energy, enthalpy, and entropy are 1061.3 h-1, 28.93 kJ/mol, 26.38 kJ/mol, and -128.41 J/mol.K, respectively. Four reusability tests were completed, and the average reusability was 78%. The obtained data indicated the excellent potential for the developed Fe3O4@MnO2 nanomaterial to act as an adsorbent, thus representing an alternative to the classical depollution methods. This study showed that nanoparticles have a photocatalytic effect against pathogenic bacteria and RhB azo dye in polluted waters and offer an effective catalytic activity to produce hydrogen as an alternative energy source.

An ultra-sensitive rifampicin electrochemical sensor based on Fe3O4 nanoparticles anchored Multiwalled Carbon nanotube modified glassy carbon electrode.

This study aimed to guide future sensor studies against other pharmaceutical drugs by synthesizing Fe3O4NPs@MWCNT metallic nanoparticles (NPs). Side damage caused by excessive accumulation of tuberculosis drugs in the body can cause clots in the organs, and cause serious damage such as heart attack and respiratory failure, and threaten human life. Therefore, the development of sensors sensitive to various antibiotics in this study is important for human health. In this study, the sensitivity of Fe3O4 NPs to tuberculosis drug (rifampicin) was evaluated by catalytic reaction using bare/GCE, MWCNT/GCE, and Fe3O4NPs@MWCNT/GCE electrodes. First of all, Fe3O4 NPs were successfully synthesized for the study and MWCNT/GCE and Fe3O4 NPs@MWCNT/GCE electrodes were formed with the modification of the MWCNT support material. It was observed that the Fe3O4 NPs@MWCNT/GCE electrode gave the highest signal against the other electrodes. The morphological structure of Fe3O4 NPs was determined by various characterization techniques such as Transmission Electron Microscopy (TEM), Fourier Transmission Infrared Spectroscopy (FTIR), ultraviolet-visible (UV-Vis), and X-ray differential (XRD) and the obtained NPs were used for sensor studies, and it was observed that the current intensity increased as the scanning speed of each electrode increased in CV and DPV measurements. The average size of Fe3O4 NPs was found to be 7.32 ± 3.2 nm. Anodic current peaks occurred in the linear range of 2-25 µM. According to the results obtained from the measurements, the limit of detection (LOD) value was calculated as 0.64 µM limit of quantification (LOQ) 1.92 µM.