Comparative investigation of binary and ternary hybrid nanocomposites synthesized from a nanoporous organic matrix

A nanoporous organic matrix (NPOM) based on pyrogallol-formaldehyde (PF) resin, a binary hybrid nanocomposite (BHyNC) obtained by incorporation of nickel oxide (NiO) nanoparticles into the PF network, and a ternary hybrid nanocomposite (THyNC), resulting from the co-integration of NiO and silica (SiO₂) nanoparticles within the same network structure were synthesized via the sol-gel process. The resulting materials were subsequently subjected to thermal treatment at 650 °C for two hours in a tubular furnace under an inert atmosphere. The XRD diffractograms display broad diffraction peaks characteristic of silica and carbon phases, along with three distinct nickel peaks observed in both BHyNC and THyNC. XPS analysis identifies five prominent peaks in the different samples corresponding to Si 2p, Si 2s, C 1s, O 1s and Ni 2p. SEM micrographs reveal a high density of particles covering the OM, particularly in the THyNC. TEM images reveal a highly porous structure in the organic matrix, a uniform dispersion of nickel nanoparticles in the BHyNC and significant nanoparticle agglomeration in the THyNC. The Raman spectra confirm the presence of a disordered graphitic structure in the various materials, as demonstrated by the D to G band intensity ratio, which ranges between 0.7 and 1. The conductance of the materials is influenced by the pore volume, showing a decrease as the pore volume increases. Electrochemical measurements demonstrate that the sensitivity of the non-enzymatic glucose sensor increases as the specific surface area decreases. According to the properties of the obtained materials, THyNC exhibited the most promising electrochemical performance as a non-enzymatic glucose sensor, whereas NPOM and BHyNC showed favorable properties for low temperature electronic applications.