A one-step method is developed for the fabrication of PtPdCu tripods with branched exteriors for the oxygen reduction reaction.

Hibiscus sabdariffa is a strongly basic dye with a large number of medicinal applications and is used for various diagnostic purposes. The biofabrication of Fe nanoparticles using Hibiscus sabdariffa (Roselle) flower extract is an eco-friendly and cost-effective protocol reported for the first time in the present investigation. The natural plant extract acts as a non-toxic, biodegradable and economical reducing agent in the biosynthesis of the Fe nanoparticles. Different well-known complementary characterization techniques such as UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray diffraction (XRD), dynamic light scattering (DLS) and thermogravimetric analysis-differential scanning calorimetry (TGA-DSC) were used to investigate the morphological, structural and optical properties of the as-synthesised Fe nanoparticles. The resulting nanoparticles were then utilized as a photocatalyst for the degradation of the toxic organic dye Congo red (CR). UV-visible spectroscopy was used to determine the photocatalytic performance of the Fe nanoparticles under UV irradiation. The results of the photocatalytic degradation of Congo red in aqueous solution under UV light showed a higher photocatalytic activity. A reasonable mechanism was proposed for the enhanced photocatalytic activity of the Fe nanoparticles.

Zeolitic imidazolate framework (ZIF) composite-derived carbon exhibiting large surface area and high micropore volume is demonstrated to be a promising electrode material for the capacitive deionization (CDI) application. However, some inherent serious issues (e.g., low electrical conductivity, narrow pore size, relatively low pore volume, etc.) are still observed for nitrogen-doped porous carbon particles, which restrict their CDI performance. To solve the above-mentioned problems, herein, we prepared gold-nanoparticle-embedded ZIF-8-derived nitrogen-doped carbon calcined at 800 °C (Au@NC800) and PEDOT doped-NC-800 (NC800-PEDOT). The newly generated NC800-PEDOT and Au@NC800 electrodes exhibited notably increased conductivity, and they also achieved high electrosorption capacities of 16.18 mg g⁻¹ and 14.31 mg g⁻¹, respectively, which were much higher than that of NC800 (8.36 mg g⁻¹). Au@NC800 and NC800-PEDOT can be promisingly applicable as highly efficient CDI electrode materials.

The bio-fabrication of silver nanoparticles (AgNPs) was carried out through the facile green route, using the aqueous extract of Matricaria chamomilla L. Herein, we have developed a cost-efficient, ecofriendly, and photo-induced method for the biomolecule-assisted synthesis of AgNPs using an aqueous extract of Matricaria chamomilla L. as a bio-reducing and capping/stabilizing agent. The biomolecule-capped AgNPs were confirmed from the surface plasmon resonance (SPR) band at λ_max = 450 nm using a UV–visible spectrometer. The stability of the AgNPs was confirmed by recording the UV–visible spectra for a more extended period, and no precipitation was observed in the sol. The morphology and structure of photo-induced biomolecule-capped AgNPs were characterized by different microscopic and spectroscopy techniques such as TEM, SEM, EDX, XRD, and FTIR analysis. The role of phytochemicals as reducing and stabilizing agents was confirmed by comparative FTIR analysis of the AgNPs and pure Matricaria chamomilla L. aqueous extract. The obtained result shows that the AgNPs are mostly spherical morphology with an average size of about 26 nm. Furthermore, the thermal stability of biomolecule-capped AgNPs was examined by TGA-DTG analysis that showed a weight loss of approximately 36.63% up to 800 °C. Moreover, the potential photocatalytic activity of photo-induced AgNPs against Rhodamine B (RB) was examined in the presence of UV light irradiation. The catalyst reusability, the effect of catalyst dosage and initial dye concentration, and the effect of the temperature and pH of the reaction medium were also assessed.