An Electrochemical Investigation of Methanol Oxidation on Thin Films of Nickel Oxide and Its Composites with Zirconium and Yttrium Oxides

Crystals

Asim Jilani¹  Javed Iqbal¹  Muhammad Adil Mansoor²  Karishma Mahmood²  Mudassir Iqbal²  S. Wageh³  Abul Kalam⁴ 

[1] Centre of Nanotechnology, King Abdulaziz University, Jeddah 21589, Saudi Arabia;Department of Chemistry, School of Natural Sciences, National University of Sciences and Technology (NUST), Islamabad 44000, Pakistan;Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia;Research Center for Advanced Materials Science (RCAMS), King Khalid University, Abha 61514, Saudi Arabia;

关键词: nickel–zirconium–yttrium oxide;    thin films;    XPS;    XRD;    methanol oxidation;   

DOI  :  10.3390/cryst12040534

来源: DOAJ

【 摘 要 】

The present work is focused on the fabrication of NiO-ZrO₂/FTO and NiO-Y₂O₃/FTO thin films via a simple dip-coating method. The films are deposited from precursor solutions of Ni(CH₃COO)₂·2H₂O, Zr(CH₃COO)₄, Y(CH₃COO)₃·H₂O in methanol. The synthesized films, after proper characterization, are employed for electrochemical oxidation of methanol. The analytical techniques such as X-ray diffraction (XRD), Raman, and Infrared (IR) spectroscopy reveal the successful formation of crystalline thin films of mixed metal oxide without any additional impurities. Further, X-ray photoelectron spectroscopy (XPS) results, confirm the composition and oxidation state of all the elements present in thin films. The field emission scanning electron microscopy (FESEM) further aided to identify the uniformity and porous nature of composite thin films while the energy-dispersive X-ray spectroscopy (EDS) confirms the targeted elemental composition of the prepared thin films is in good agreement with precursors. The electrochemical oxidation of methanol results reveals that NiO-Y₂O₃/FTO and NiO-ZrO₂/FTO thin films showed current densities of 6.2 mA/cm² and 10 mA/cm² at 0.65 V, respectively, against Ag/AgCl/3M KCl using 0.6 M methanol solution. Furthermore, Chronoamperometric (CA) results show good stability of NiO-ZrO₂/FTO and NiO-Y₂O₃/FTO thin films with observed current decay of 10% and 6.8% of the initial current density, respectively. Moreover, the effect of scan rate and concentration of metals in a catalyst was also investigated. The Electrochemical impedance studies (EIS) further support electrochemical results, where the lower charge transfer resistance (R_ct) values are recorded for composite thin films as compared to the pure metal oxide thin films (NiO/FTO, ZrO₂/FTO, and Y₂O₃/FTO).

【 授权许可】

Unknown