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In this study, the electrocatalytic characteristics of nitrogen‐doped carbon (NDC) prepared from Clerodendrum Infortunatum L leaves on a glassy carbon electrode (GCE) surface was evaluated with regards to its ability to detect the electroactive drug ketoconazole (KCZ). The NDC was prepared by carrying out a simple pyrolysis of dry powder of the leaves at 850 °C. The prepared NDC was characterized using field‐emission scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy, X‐ray photoelectron spectroscopy and Brunauer‐Emmett‐Teller analysis, and was then used as an electrode material. The performance of the electrochemical KCZ sensor with the NDC‐modified glassy carbon electrode (NDC/GCE) was found to be optimal when using PBS buffer at pH 3 and a concentration of 0.1 mg/ml of NDC in the conjugate with Nafion polymer. Under these conditions, the NDC/GCE displayed a KCZ detection limit of 3 μM and a linear dependence of its response on KCZ concentration over a wide range of KCZ concentrations from 47 μM to 752 μM (R2=0.9742). These results confirmed the potential of NDC as an electrocatalyst.

Despite the growing popularity and promising properties of aluminum-doped zinc oxide (AZO) among other transparent conducting oxides (TCOs), modification of AZO with a suitable nano-catalyst can help to enhance its electrocatalytic properties. In this study, the surface of AZO is decorated with palladium nanoparticles (PdNPs) by simply Pd ion capturing on bare AZO from an aqueous solution of K 2 PdCl 4 and successive reduction with NaBH 4 to enhance the electrocatalytic properties toward water oxidation. The effect of K 2 PdCl 4 concentration is optimized for optimum PdNPs-modified AZO (PdNPs-AZO) electrodes for electrochemical water oxidation. The surface morphology, elemental composition, and electrical properties of the prepared PdNPs-AZO were examined by field emission scanning electron microscopy, energy dispersive spectroscopy, and four-in-line probe, respectively. The PdNPs-AZO electrodes, prepared with various concentrations of Pd precursors, exhibited a significant change in terms of electrode sheet resistance and resistivity from each other. The electrochemical impedance spectroscopy and cyclic voltammetry were conducted in a 0.1 M NaOH (aq.) solution to achieve quantitative information about the electrodes and electrochemical reactions toward water oxidation. The PdNPs-AZO prepared with 5.0 mM K 2 PdCl 4 exhibited optimum behavior toward water oxidation with the starting oxidation potential of 625.7 mV vs. Ag/AgCl and current density of 13.8 mA cm -2 at 1.5 V vs. Ag/AgCl.

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