Effect of Ni Addition on Catalytic Performance of Fe87Si5B2P3Nb2Cu1 Amorphous Alloys for Degrading Methylene Blue Dyes

Fe/Au galvanic nanocells to generate self-sustained Fenton reactions without additives at neutral pH

The generation of reactive oxygen species (ROS) via the Fenton reaction has received significant attention for widespread applications. This reaction can be triggered by zero-valent metal nanoparticles by converting externally added H2O2 into hydroxyl radicals (˙OH) in acidic media. To avoid the addition of external additives or energy supply, developing self-sustained catalytic systems enabling onsite production of H2O2 at a neutral pH is crucial. Here, we present novel galvanic nanocells (GNCs) based on metallic Fe/Au bilayers on arrays of nanoporous silica nanostructures for the generation of self-sustained Fenton reactions. These GNCs exploit the large electrochemical potential difference between the Fe and Au layers to enable direct H2O2 production and efficient release of Fe2+ in water at neutral pH, thereby triggering the Fenton reaction. Additionally, the GNCs promote Fe2+/Fe3+ circulation and minimize side reactions that passivate the iron surface to enhance their reactivity. The capability to directly trigger the Fenton reaction in water at pH 7 is demonstrated by the fast degradation and mineralization of organic pollutants, by using tiny amounts of catalyst. The self-generated H2O2 and its transformation into ˙OH in a neutral environment provide a promising route not only in environmental remediation but also to produce therapeutic ROS and address the limitations of Fenton catalytic nanostructures.

Oxide-based catalysis: tailoring surface structures via organic ligands and related interfacial charge carrier for environmental remediation

Hierarchical nanostructures and the effects of ligands on their structure formation were investigated. Morphological analysis showed the change in the morphology from nanospindles to hollow hexagonal nanodisks with the change in ligands. Structural analysis exhibited the formation of both hexagonal ZnO and monoclinic CuO structures in the composition. The elemental composition confirms the presence of CuO and ZnO in the composition. An ultra-fast degradation was achieved for the nanocomposites. The ZnO/CuO composite with ethylenediamine showed the best activity by degrading 98.77% of the methylene blue dye in 36 min. A possible photocatalytic mechanism is proposed.