Vermiculture-based molybdenum oxide nanoparticles synthesis, optimization, characterization and its impact on seed germination and seedling characteristics in green gram (Vigna radiata)

Abstract

Here, we report the biosynthesis of molybdenum oxide (Mo5O14) nanoparticles (NPs) by co-precipitation methods using various vermiculture-based extracts and their impact on seed germination in Vigna radiata. The synthesis of Mo5O14 NPs was initially characterized by a color change from yellow to white and a surface plasmon resonance (SPR) peak at 360 nm in UV–visible spectroscopic analysis. In addition, X-ray diffraction (XRD) data revealed that the Mo5O14 NPs were crystalline with a tetragonal structure and a size of 35.32–41.86 nm. Furthermore, fourier transform infrared (FTIR) analysis of NPs absorption bands revealed the presence of unique functional groups, such as -OH stretching, CH2 stretching, and primary amide groups, providing strong evidence that the native protein served to a reduce, cap, and stabilize Mo5O14 NPs. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images revealed that the ultrastructural profile of Mo5O14 NPs formed rod particles with an average particle length of 102 nm and width of 33 nm. The energy dispersive X-ray (EDX) pattern analysis confirmed the presence of Mo and O ions. Finally, the effects of Mo5O14 NPs on Vigna radiata seed fresh and dry biomass characteristics, root and shoot length, and seed germination were investigated, and it was found that a significant increase in the seed germination rate of all seven vermiculture-based Mo5O14 NPs was observed at 200 ppm. Consequently, our work provides a step forward in the development of vermiculture-based Mo5O14 NPs as a promising green agrochemical nano-fertilizer.