Bioinspired NiCoO2 nanocomposites derived from Moringa oleifera as a recyclable catalyst for multicomponent reactions with potent antimicrobial efficiency

A green synthetic approach was developed to produce NiCoO2 nanocomposite using an aqueous extract of Moringa oleifera which acts as both a reducing and stabilizing agent. The fabrication of NiCoO2 nanocomposites have shown successful crystalline synthesis with effective antimicrobial performance. These nanocomposites were extensively characterized using techniques such as UV–visible, FTIR,XRD,SEM, EDS, BET and fluorescence spectroscopy. These analyses confirmed their crystalline structure, elemental composition, thermal stability, and distinct surface functional groups. The synthesized materials were used for antimicrobial study against bacterial strains such as S. aureus, B. cereus, P. vulgaris, and S. typhimurium. The results demonstrated strong antimicrobial efficacy of the prepared materials. As heterogeneous catalysts, the NiCoO2 nanocomposites were deployed in a one pot multicomponent condensation reaction involving aldehyde, hydrazine hydrate, barbituric acid and ethyl acetoacetate under ultrasonicator. This protocol yielded pyrazolopyrano[2,3-d]pyrimidinederivatives with up to 98% efficiency within remarkably short reaction times. The catalyst retained its activity over five consecutive cycles, indicative of excellent recyclability. Additionally, the final products exhibited excellent antimicrobial efficacy against Gram-positive and Gram-negative microorganisms. Such antimicrobial efficacy is in line with established findings on NiCoO2 nanocomposite, which typically exhibit greater bacteriostatic effects than other metal oxides. This methodology embodies the principles of green chemistry by using renewable plant-derived extracts, mild reaction conditions, ultrasonic assistance, and recycle nanocatalysts. It provides a sustainable, cost-effective strategy for nanocomposite production and heterocyclic compound synthesis, reinforcing eco-friendly advancements in nanotechnology and catalysis.