Accurate and precise control of the transition-metal ions in the docking sites of porous functional materials especially covalent-organic frameworks (COFs) is a challenging task in the synthesis of hybrid materials. In this work, we demonstrate the successful synthesis, characterization, and utilization of two stable vanadium docked COFs, namely VO-TAPT-2,3-DHTA and VO-PyTTA-2,3-DHTA as efficient heterogeneous catalysts for Mannich-type reactions. The obtained results revealed that the as-prepared vanadium-decorated COFs are robust and maintain framework crystallinity, reusability, and efficiency under the sway of electronic and steric effects. Significantly, this work opens up the opportunity for docking other metals and exploring practically and industrially important catalytic reactions.

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In this work, CdS/ZnO composite nanofibers (NFs) were prepared by the electrospinning of a sol–gel comprised of poly(caprolactone), zinc acetate dihydrate, cadmium acetate dihydrate, and ammonium sulfide. The electrospun NF mats were calcined under vacuum in an argon (Ar) atmosphere at 200 °C for 1 h. Standard physiochemical analysis techniques demonstrated the formation of the crystalline hexagonal phase of CdS and ZnO. Composite NFs showed good photocatalytic degradation of methylene blue (MB) dye under visible light irradiation compared to their counterparts. CdS nanoparticles, ZnO nanofibers, and composite NFs photodegraded 35.5%, 47.3%, and 90% of the MB dye, respectively, within 100 min. The reaction kinetics of MB photodegradation using the composite NFs followed the pseudo-first-order relation. Owing to their facile preparation and good photodegradation ability, the proposed method can be used to prepare various photocatalysts for wastewater treatment.

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Nanobiotechnology has offered great attention in drug delivery and the development of various medicines used to treat microorganism infections. The present investigation deals with antimycobacterial activity, in-vitro hemolysis assay, and antioxidant activity of nickel oxide nanoparticles (NiO NPs). NiO NPs, with controlled size and shape, prepared by a simple and inexpensive successive ionic layer adsorption and reaction (SILAR) method was scanned using field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM) digital images for surface morphology confirmation. Spherical irregular island-type NPs of about 24 nm diameter are obtained. The X-ray diffraction pattern demonstrates the synthesis of polycrystalline and cubic in phase NiO NPs. The Raman spectrum has revealed the presence of two vibration bands cantered at 550 and 1095 cm−1 for one photon longitudinal optical, and two longitudinal optical modes, respectively. The as-prepared NiO NPs endow 10 µg/mL against Mycobacterium tuberculosis (M. tuberculosis, MTCC-300) and 10 µg/mL against Mycobacterium phlei (M. phlei, MTCC-1723) inhibitory concentrations. The hemolytic activity of NiO NPs has also been explored. The antioxidant result demonstrates 63.44% for NiO NPs over 88.23% for standard, i.e., di(phenyl)-(2, 4, 6-trinitrophenyl) viminoazaniun antioxidant. Taken together, NiO NPs act as a potential candidate against mycobacteria.