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Metal–organic frameworks (MOFs) are the more desirable electrode materials in the recent development of electrocatalyts. Still, the electrocatalytic behavior as well as the stability of the prepared MOFs were diminished by its poor conductance. In this work, Cobalt hydroxide (Co (OH)2) functionalized multi-walled carbon nanotubes (MWCNTs) with enhanced electro activity has been prepared using Co-based metal−organic framework (Co MOF, ZIF-67) templates through room temperature electrochemical synthesis. The as synthesized composite has been utilized in the construction of MWCNTs-Co(OH)2 modified glassy carbon electrode (GCE) for the determination of hydrazine (N2H4) and hydrogen peroxide (H2O2). The higher electrochemical performance of MWCNTs-Co(OH)2/GCE compared to individual MWCNTs/GCE and Co(OH)2/GCE was evident from the cyclic voltammetric studies. The characterizations of the composite have been carried out using various techniques. The electrochemical parameters such as linear range, limits of detection and sensitivity of MWCNTs-Co(OH)2/GCE were found to be more comparable with the previous N2H4 and H2O2 amperometric sensors reported in the literatures. The outcomes of practicability inspections were adequate with the recovery results of conventional methods. The high selectivity of MWCNTs-Co(OH)2 modified GCE towards N2H4 and H2O2 has been further demonstrated in the presence of several biologically interfering molecules.

Hydrogen peroxide (H2O2) sensing and oxygen reduction reaction (ORR) has considered to be a highly desirable in the areas of sensing and energy production. In recent years, researchers focus on the replacement of noble metal-based electrocatalyst used for the ORR and H2O2 sensing by low-cost materials. In this current work, we have synthesized carbon black supported LaMnO3 (LMO@C) via dry particle coating method and studied its electrocatalytic activity towards ORR and H2O2 sensing. The characterization of synthesized LMO@C was performed by using field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) spectroscopy, X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy techniques. Furthermore, the synergistic effect between LMO and carbon was established through electrochemical measurements. In case of ORR, our prepared LMO@C composite possess longer life-time (89.8%) than 20 wt% Pt/C (77.6%). In another case, this electrocatalyst (LMO@C) owns wide working range, low limits of detection and high sensitivity for the determination of H2O2. The experimental data of LMO@C towards the electrochemical sensing of H2O2 and ORR demonstrates its potential applications in the construction of sensors and energy generation devices.

We have synthesized the hierarchical mesoporous graphite oxide (HMGO) through simple single step carbonization method by using MIL-100(Al) metal-organic framework as a template. To study the influence of temperature in the synthesis of HMGO, various carbonization temperatures (700, 800, and 900 °C) were fixed without any additional carbon sources. The newly prepared HMGO showed uniform morphology, pore-size distribution centered on 10 nm with high surface area (370–470 m2/g) and excellent electrochemical ability. Hence, we have constructed an amperometric sensor for the trace level detection of caffeic acid (CA) by using HMGO as a modifier in glassy carbon electrode (GCE). The good electro catalytic activity of HMGO film modified GCE can be explained from the low over potential and high redox peak current obtained toward the detection of CA. Our demonstrated sensor works in a wide linear range (0.01–608 µM) with low limits of detection (0.004 µM) and high sensitivity (429 µA/mM/cm2). In addition, the selective determination of CA even in presence of other interfering molecules, reveals the good selectivity of HMGO/GCE. The commercially available wine samples were further utilized to demonstrate the practical feasibility of HMGO modified GCE. The acceptable values of stability, repeatability and reproducibility also support the practical applications of our fabricated electrode.