ABSTRACT
The sustainable catalytic efficacy of transition metal oxides (TMO) and rare earth element-based oxides positions them as pivotal materials for effectively treating contaminated wastewater. This study successfully synthesized a series of Ce@MnO2 photocatalysts using a straightforward hydrothermal method. These photocatalysts were thoroughly characterized for their optical properties, structural morphology, and phase purity. Among the synthesized materials, the Ce@MnO2 (40:60) exhibited the highest photocatalytic activity for the degradation of Acebutolol (ACB), achieving a remarkable degradation efficiency of 92.71% within 90 min under visible light irradiation. This superior performance is attributed to the increased presence of active species and the efficient separation of photogenerated carriers. Additionally, the photocatalytic reaction mechanism was elucidated, highlighting the catalyst's surface charge properties which significantly enhanced performance in a solution with pH 8. The outstanding photo-response in the visible spectrum renders this method not only cost-effective but also environmentally benign, presenting a promising approach for large-scale water purification.
ABSTRACT
The release of organic dyes into water systems, mainly textile industries, poses a significant threat to human and animal health. This approach shows great potential for effectively removing harmful dyes and microorganisms from wastewater treatment for environmental remediation. This study utilized gum karaya polymer bio-reductant to synthesize manganese oxide (MnO2) nanoparticles through a green approach. The synthesized MnO2 nanoparticles were characterized and confirmed by various analytical techniques. These results revealed their nanoscale dimensions, morphology, chemical purity, crystal nature, decolorized intermediate, and band gap. The photocatalytic degradation of hazardous Congo red and methyl orange dyes using KRG-MnO2 nanoparticles under visible light irradiation. Furthermore, the results demonstrated that Congo red dye degradation efficiency of 93.34 % was achieved. The dye concentration (8 to 16 mg/L), pH concentration, and radical trapping were studied. This suggests that holes and hydroxyl radicals play a crucial role in degrading the Congo red dye and demonstrate superior recyclability after three successive cycles and good stability. The possible intermediates from the Congo red dye degradation were identified through LC-MS analysis. The polymer composite MnO2 NPs have displayed notable antibacterial activity against pathogenic bacteria such as Staphylococcus aureus and Escherichia coli. The research indicates that MnO2 nanoparticles functionalized with polymers can efficiently remove pathogens and organic dyes from diverse industrial water treatment processes.
Subject(s)
Anti-Bacterial Agents , Coloring Agents , Congo Red , Karaya Gum , Manganese Compounds , Nanoparticles , Oxides , Manganese Compounds/chemistry , Oxides/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Coloring Agents/chemistry , Catalysis , Congo Red/chemistry , Nanoparticles/chemistry , Karaya Gum/chemistry , Green Chemistry Technology , Azo Compounds/chemistry , Staphylococcus aureus/drug effects , Water Pollutants, Chemical/chemistry , Escherichia coli/drug effects , Water Purification/methods , Light , PhotolysisABSTRACT
Intense studies are being carried out on single atom catalysts that exhibit remarkable activity and selectivity. To enhance their catalytic abilities, one must have a thorough understanding of the properties of the single metal atom active site and its dynamics in the working state. Herein, we report single metal atom oxide (SMAO) (metal: W/Cu) anchored on TiO2-rGO nanomaterials (SMAO-ED-TiO2-rGO) by simple sonication process. It is efficient for the electrocatalytic hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and photocatalytic degradation of pharmaceutical pollutant. The uniform dispersion of the tungsten/copper metal atom oxide over a TiO2-rGO materials is detected by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The SMAO-ED-TiO2-rGO nanocatalyst has shown impressive HER/OER activity with an overpotential of 121/295 mV at (-)10 mA cm-2 current density and the low Tafel slope of 96/60.3 mV dec-1 in 1 M KOH solution. Further, SMAO-ED-TiO2-rGO nanocatalyst was used for the photocatalytic degradation of ciprofloxacin (CF). After 60 min of UV light irradiation, the SMAO-ED-TiO2-rGO nanocatalyst efficiently photodegraded 98.5% of CF while retaining its activity for five cycles. Superoxide radicals (O2â¢-) are found to be the main reactive species required in the photodegradation of CF, according to scavenger study of the SMAO-ED-TiO2-rGO nanocatalyst for CF degradation.
