Synergistic effect of band edge potentials on BiFeO3/V2O5 composite: Enhanced photo catalytic activity

The BiFeO₃/V₂O₅ has been successfully synthesized by simple annealing of BiFeO₃ nanoplates and V₂O₅ nanoflower. The phase, structural, optical properties and chemical state of the BiFeO₃, V₂O₅ and different composition of BiFeO₃/V₂O₅ samples were comparatively characterized by various spectroscopic and microscopic techniques. The prepared catalyst exhibits unique photo catalytic and post-oxidation/reduction ability for removal of various (MB, Phenol, CV, RhB) water organic pollutants. Compared to pure BiFeO₃ and V₂O₅, the different Wt % of BiFeO₃/V₂O₅ composition exhibited higher photo catalytic activity. The fortunate BiFeO₃/V₂O₅ interface hybrid photo catalyst makes a significant impact in the enhancement of photo catalytic reaction. This remarkable efficiency could be ascribed to the synergistic effect between the V₂O₅ petals and BiFeO₃ plates. The exceptional morphology, increased surface area, uniformity, less-agglomerated spreading could increase the ability of visible light response, which lead the improved electron transport ability and the higher charge separation. The enhanced rate of photo generated charge carriers separations were evinced by the EIS and PL spectrum measurements. The allowed radical trapping experiment divulge that the hole (h⁺), and super oxide radical (O₂-) are the minimized effect in degradation, on the other hand hydroxyl radical (OH) is plays the foremost role and act as the active radicals in the catalytic organism. In relations of above investigation, a probable photo degradation mechanism of the as-synthesized photo catalyst is carefully explicated. This effort delivers an effective approach to design and fabricate the efficient photo catalyst through integrating of materials, which has a potential for industrial waste water purification.

Recyclable Au/SiO2-Shell/Fe3O4-Core Catalyst for the Reduction of Nitro Aromatic Compounds in Aqueous Solution

Highly stable gold nanoparticles immobilized on the surface of amine-functionalized nanocomposite microspheres possessing a magnetite (Fe₃O₄) nanoparticle core and a silica (SiO₂) shell (Au/SiO₂-shell/Fe₃O₄-core) were prepared. These gold nanocomposite catalysts were tested for 4-nitrophenol (4-NP) and 2-nitroaniline (2-NA) reduction in aqueous solution in the temperature range 293-323 K and in the presence of aqueous NaBH₄ reducing agent. The magnetically recyclable gold catalyst showed high stability (∼3 months), efficient recyclability (up to 10 cycles), and high activity (∼100% conversion within 225 s, ∼700 ppm 4-NP or 2-NA). The pseudo-first-order apparent reaction rate constants (k) of 4-NP and 2-NA reduction were 7.5 × 10^-3 and 4.1 × 10^-3 s^-1, respectively, and with an apparent catalytic activity of 4.48 × 10^-8 kmol/(m³ s).

Precious metal-like oxide-free copper nanoparticles: high oxidation resistance and geometric structure

Precious metal-like oxide-free copper nanoparticles, which are desired for alternatives as precious metal nanoparticles, were synthesized by environmental-friendly photoreduction method.