Electrochemical behavior of three biologically important triazole and phenol containing Schiff bases (E)-3-((4H-1,2,4 triazol-4ylimino) methyl)benzene-1,2-diol (TMB), (E)-3-((4H-1,2,4 triazol-4-ylimino) methyl)para-phenol (p-TMP) and (E)-3-((4H-1,2,4 triazol-4-ylimino) methyl)ortho-phenol (o-TMP) were investigated by electrochemical, spectroscopic and computational methods. The peak potential of all the three compounds showed a linear dependence on pH under acidic conditions, but under alkaline conditions, electron transfer was not coupled to proton transfer. The acid-base dissociation constant (pKa) values of the compounds were evaluated both by electrochemical and UV-Vis spectroscopic techniques. On the basis of experimental and theoretical findings, redox mechanisms of the compounds were proposed and certain important kinetic and thermodynamic parameters were determined from their temperature and pH responsive redox response. Our studies showed a) low cytotoxicity for all three triazoles and b) antioxidant properties of these triazoles. TMB was found as the most promising antioxidant, which makes this compound interesting as a basis for further development as food supplement.

Over the past decade, layered double hydroxides (LDH) have been the subject of extensive investigations owing to their remarkable water splitting catalytic activity. Stability and porosity are several of the features of LDH which help them to serve as efficient oxygen evolution reaction (OER) catalysts. Based on these considerations, we synthesized NiCo(OH)2 LDH and probed its OER electrocatalytic performance. The synthesized catalyst was subjected to X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy for structural analysis and investigation of its surface morphology, surface composition, and oxidation states. The LDH-NiCo(OH)2 was anchored over the FTO surface and the fabricated electrode was found to exhibit a much lower OER onset potential of 265 mV, a much higher current density of 300 mAcm−2 and a smaller Tafel slope of 41 mVdec−1. Moreover, the designed catalyst was found to be stable up to 2500 repeated voltametric scans. These figures of merit regarding the structure and performance of the designed LDH are expected to provide useful insights into the fundamental understanding of the OER catalysts and their mechanisms of action, thus enabling the more rational design of cost effective and highly efficient electrocatalysts for use in water splitting.

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