Developing the most straightforward, cheapest, and eco-friendly approaches for synthesizing nanostructures with well-defined morphology having the highest possible surface area to volume ratio is challenging for design and process. In the present work, nanosheets of NiO and β-Ni(OH) 2 /Co 3 O 4 , and nanorods of Co 3 O 4 have been synthesized at a large scale via the microwave-assisted chemical coprecipitation method under low temperature and atmospheric pressure. X-ray absorption spectroscopy (XAS) measurements, which comprises both X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) techniques, have been carried out at Co and Ni K-edges to probe the electronic structure of the samples. Also, the local atomic structural, chemical bonding, morphological, and optical properties of the sample were systematically investigated using XAS, synchrotron X-ray diffraction (SXRD), Raman spectroscopy, FTIR, transmission electron microscopy (TEM), and UV–visible spectroscopy. The normalized XANES spectra of the β-Ni(OH) 2 /Co 3 O 4 nanosheets show the presence of Ni 2+ and a mixed oxidation state of Co. The disorder factor decreases from β-Ni(OH) 2 /Co 3 O 4 to Co 3 O 4 with increasing Co–O bond length. The SXRD pattern analyzed using Rietveld refinement reveals that NiO has a face-centered cubic phase, Co 3 O 4 has the standard spinal structure, and β-Ni(OH) 2 /Co 3 O 4 has a mixed phase of hexagonal and cubic structures. TEM images revealed the formation of nanosheets for NiO and β-Ni(OH) 2 /Co 3 O 4 samples and nanorods for Co 3 O 4 samples. FTIR and Raman spectra show the formation of β-Ni(OH) 2 /Co 3 O 4 , which reveals the fingerprints of Ni–O and Co–O.

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The orthorhombic MoO3 micro-strips sample was synthesized using microwave assisted chemical co-precipitation technique. Synchrotron X-ray Diffraction (SXRD) pattern and Rietveld Refinement was used to estimate structural parameter, crystallite size of sample. It reveals that the synthesized sample MoO3 crystallized as an orthorhombic phase. X-ray Absorption Spectroscopy (XAS) measurement, which comprises both X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) techniques, have been carried out on Mo K-edge to probe the local structure of samples. Local structure is also confirmed from the SXRD and Raman spectra of sample. XAS measurement reveals that the first bond length of Mo-O and Mo-Mo is 1.69 and 3.42 Å in orthorhombic MoO3 respectively. Transmission electron microscopy and SAED patterns showed stripe-like structure and single-crystal formation of MoO3 respectively.