Valorizing BananaPeel Waste into Mesoporous BiogenicNanosilica and Novel Nano-biofertilizer Formulation Thereof via Nano-bioprimingInspired Tripartite Interaction Studies

The present study attempts to valorize banana peel waste (BPW) into high-value precipitated nanosilica-based agri-input. XRD analysis revealed smaller-sized biogenic nanosilica (BNS) with an increase (without heating) or decrease (with heating) in the duration of acid pretreatment during the pre-calcination step. The highest BNS yield was recorded in post-calcinated BPW ash involving simultaneous acid and heat treatment (1 h) (SA-3). FTIR analysis displayed an intense peak at 1078.3 cm^–1, indicating “Si–O–Si bond” asymmetric vibrations. FESEM-EDX micrographs revealed high-purity BNS of predominantly spheroid morphology. The BJH plot exhibited mesoporous nanosilica with a median pore diameter of ∼33.82 nm. The bipartite interaction of 0.001 g mL^–1 BNS signifies growth-promoting effects on <i>Bacillus subtilis</i> (BS) and <i>Raphanus sativus</i> (RS). The nano-primed RS seeds showed higher germination indices over non-primed seeds at 0.001 g of BNS mL^–1. Further, the nano-biopriming studies showed the synergistic response of BNS and BS interaction on RS seeds in terms of higher seedling growth, biomass content, and stress tolerance index. The findings open new avenues for developing nano-biofertilizer formulations that serve multifaceted functions such as waste management and biomass valorization into value-added products and fulfill sustainable development goals.