The strategy for organic dye and antibiotic photocatalytic removal for water remediation in an example of Co-SnO2 nanoparticles

Adsorption performance with field emission scanning electron microscopy of fruit peel induced Silver Nanoparticles in C16H18ClN3S for waste water treatment

There is a growing demand for cost-effective and sustainable technologies for treating wastewater as water consumption increases and conventional technologies become more expensive. Nanoparticles have a great deal of potential for use in the treatment of waste water. Their unique surface area allows them to effectively remove toxic metal ions, pathogenic microorganisms, organic and inorganic solutes from water. This study investigated the potential of orange and banana peels as renewable nano adsorbents for removing dyes and dissolved organic compounds from textile wastewater. Orange and banana peels are an optimal selection due to their favourable chemical characteristics, namely the presence of cellulose, pectic, hemicellulose, and lignin. Their capacity to adsorb diverse anionic and cationic compounds on their surface-active sites is attributed to their unique functional group compositions. Silver nanoparticles are able to adsorb heavy metals due to their exceptionally low electrical and thermal resistance and surface plasmon resonance. The samples were thoroughly characterised using field emission scanning electron microscopy (FESEM), UV-Visible spectrometry, Fourier transform infrared spectroscopy (FTIR) and XRD. The nanoparticles were prepared (10 gm,50 gm,100 gm) and subsequently introduced to the wastewater sample. The optical density values were recorded at various time points. The optical density values demonstrate a decline over the course of the experiment, with a notable decrease observed over time. The results of this study provide valuable insights into the efficacy of these natural adsorbents and their potential for sustainable water purification technologies. For the purpose of this research, high performance instrumentation methods were performed as follows:•Field emission scanning electron microscopy for surface morphology studies.•Gas chromatography-mass spectrometry (GC-MS) for analytical technique that combines gas chromatography (GC) and mass spectrometry (MS) to identify unknown substances or contaminants.•Optical density values were measured for different timings of degradation.

One-step in-situ construction engineering of ZnO-Zn2SnO4 heterojunction for deeply photocatalytic oxidation of nitric oxide

The generation of hazardous intermediates during the process of photocatalytic nitric oxide (NO) oxidation presents a tough issue. Herein, a one-step microwave strategy was employed to introduce oxygen vacancies (OVs) into zinc oxide-zinc stannate (ZnO-Zn2SnO4) heterojunction, resulting in an improvement in the photocatalytic efficiency for NO removal. The construction ZnO-Zn2SnO4 heterojunction with the OVs (ZSO-3) owns a significant contribution towards highly efficient electron transfer efficiency (99.7%), which renders ZSO-3 to exert a deep oxidation of NO-to-nitrate (NO3-) rather than NO-to-nitrite (NO2-) or NO-to-nitrogen dioxide (NO2). Based on the solid supports of experimental and simulated calculations, it can be found that OVs play an irreplaceable role in activating small molecules such as NO and O2. Moreover, the enhanced adsorption capacity of small molecules, which guarantees the high yield of active radical due to the formation of S-scheme heterojunction. This work illuminates a novel viewpoint on one-step in-situ route to prepare Zn2SnO4-based heterojunction photocatalyst with deep oxidation ability of NO-to-NO3-.

Fast and ecofriendly triple sulfonamides mixture utilization using UV irradiation and spherical SnO2 nanoparticles with controllable parameters and antibacterial activity

One of the solutions for the growing problem of water purification is photocatalytic degradation of the pollutants. Semiconductor nanoparticles are widely under study as a promising photocatalyst for this purpose. However, there is still lack of understanding of the relation between properties of nanoparticles, in their turn related with synthesis conditions, and photocatalytic efficiency, as well as of the other factors influencing the process. For the first time, a possibility to regulate photocatalytic activity of SnO2 nanoparticles under UV light via regulation of structural parameters is shown. A method for obtaining spherical nanoparticles with different parameters was developed. Obtained nanoparticles were fully characterized. Special attention was paid to the study of oxygen vacancies. With the help of quantum computational methods, it was shown, that the concentration of vacancies is around 1 per 32 tin atoms. Obtained data on oxygen vacancies were further used for the evaluation of pollutant-nanoparticle surface interaction to get closer to the calculations of real systems. On the example of methylene blue, it was shown that the greater is the amount of oxygen vacancies and the lower the amount of defects, the higher photocatalytic activity. The obtained dependence is confirmed by the fact that the photoresponse increases with a decrease of amount of defects in the sample. Degradation kinetics of sulfonamides mixture was studied, and its dependence on active complex formation was shown based on the quantum chemical calculation data. Degradation of antibiotics in water from Neva River reached more than 95% in 35 min, which indicates that developed photocatalyst efficiency is not affected by pollutants contained in open water in the centre of the metropolis. It was shown, that the use of nanoparticles allows to speed up the process of bacteria destruction under UV light, which indicates the antibacterial activity of obtained nanoparticles.