Four 3d−4f hetero-polymetallic complexes [Fe 2 Ln 2 ((OCH 2 ) 3 CR) 2 (O 2 C t Bu) 6 (H 2 O) 4 ] (where Ln = La (1 and 2) and Gd (3 and 4); and R = Me (1 and 3) and Et (2 and 4)) are synthesized and analyzed using elemental analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, and SQUID magnetometry. Crystal structures are obtained for both methyl derivatives and show that the complexes are isostructural and adopt a defective dicubane topology. The four heavy metals are connected with two alkoxide bridges. These four precursors are used as single-source precursors to prepare rare-earth orthoferrite pervoskites of the form LnFeO 3 . Thermal decomposition in a ceramic boat in a tube furnace gives orthorhombic LnFeO 3 powders using optimized temperatures and decomposition times: LaFeO 3 formed at 650 °C over 30 min, whereas GdFeO 3 formed at 750 °C over 18 h. These materials are structurally characterized using powder X-ray diffraction, Raman spectroscopy, scanning electron microscopy, energy-dispersive X-ray map spectroscopy, and SQUID magnetometry. EDX spectroscopy mapping reveals a homogeneous spatial distribution of elements for all four materials consistent with LnFeO 3 . Magnetic measurements on complexes 1−4 confirm the presence of weak antiferromagnetic coupling between the central Fe(III) ions of the clusters and negligible ferromagnetic interaction with peripheral Gd(III) ions in 3 and 4. Zero-field-cooled and field-cooled measurements of magnetization of LaFeO 3 and GdFeO 3 in the solid-state suggest that both materials are ferromagnetic, and both materials show open magnetic hysteresis loops at 5 and 300 K, with M sat higher than previously reported for these nanomaterials. We conclude that this is a new and facile low temperature route to these important magnetic materials that is potentially universal, limited only by what metals can be programmed into the precursor complexes.

ZnO and TiO2 are both well-known electron transport materials; however, an exact comparison of their performance, when fabricated under the same synthesis conditions, is missing in the literature. Considering this, we introduced a viable electrospinning route for the development of highly polycrystalline TiO2 and ZnO nanofibers for an electron transport material (ETM) of perovskite solar cells and photocatalysts for textiles. Thanks to the effective tuning of band structure and morphology of TiO2, a significant improvement in performance as compared to ZnO was observed when both were used as photoanodes and photocatalysts. X-ray diffraction detected polycrystalline structural properties and showed that peaks are highly corresponding to TiO2 and ZnO. Morphological analysis was carried out with a scanning electron microscope, which revealed that nanofibers are long, uniform, and polycrystalline, having diameter in the nano regime. TiO2 nanofibers are more aligned and electron-supportive for conduction as compared to ZnO nanofibers, which are dense and agglomerated at some points. Optoelectronic properties showed that TiO2 and ZnO show absorption values in the range of ultraviolet, and visible range and band gap values for TiO2 and ZnO were 3.3 and 3.2 eV, respectively. The TiO2 band gap and semiconductor nature was more compatible for ETL as compared to ZnO. Electrical studies revealed that TiO2 nanofibers have enhanced values of conductivity and sheet carrier mobility as compared to ZnO nanofibers. Therefore, a higher photovoltaic conversion efficiency and antibacterial activity was achieved for TiO2 nanofibers (10.33%), as compared to ZnO (8.48%). In addition, the antibacterial activity of TiO2 was also recorded as better than ZnO. Similarly, compared to ZnO nanofibers, TiO2 nanofibers possess enhanced photoactivity for antimicrobial and dye degradation effects when applied to fabrics.

Hazardous dyes in industrial wastewater are an internationally recognized issue for community health. Nanoparticles synthesized through green protocols are a fascinating research field with numerous applications. The current study mainly aimed to investigate the degradation of Congo red (CR) dye under UV light in the presence of H2O2 and the photocatalytic activity of copper oxide nanoparticles (CuONPs). For CuONP formation, Citrus maxima extract contains a high number of phytochemical constituents. The size of CuONPs ranges between 25 and 90 nm. The photocatalytic activity of CuONPs with the addition of H2O2 was observed and analyzed under UV light to eliminate CR dye. The UV light caused the decomposition of H2O2, which produced ·OH radicals. The results revealed a significant increment in dye degradation during the presence of H2O2. The effect of concentration on the degradation of the CR dye was also studied. The degradation pathway of organic pollutants was reputable from the hydroxy radical medicated degradation of CR. Advanced Oxidation Treatment depends on the in situ production of reactive ·OH species and is presented as the most effective procedure for decontamination. The biological activity of CuONPs was evaluated against Escherichia coli Bacillus subtillis, Staphylococcus aureus, Shigella flexenari, Acinetobacter Klebsiella pneumonia, Salmonella typhi and Micrococcus luteus. The newly synthesised nanomaterials showed strong inhibition activity against Escherichia coli (45%), Bacillus subtilis (42%) and Acinetobacter species (25%). The activity of CuONPs was also investigated against different fungus species such as: Aspergillus flavus, A. niger, Candida glabrata, T. longifusus, M. Canis, C. glabrata and showed a good inhibition zone against Candida glabrata 75%, Aspergillus flavus 68%, T. longifusus 60%. The materials showed good activity against C. glaberata, A. flavus and T. longifusus. Furthermore, CuONPs were tested for antioxidant properties using 2, 2 diphenyl-1-picrylhydrazyl) (DPPH).

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