Investigation of solar-induced photoelectrochemical water splitting and photocatalytic dye removal activities of camphor sulfonic acid doped polyaniline-WO₃-MWCNT ternary nanocomposite

Mir Ghasem Hosseini^1,2，Pariya Yardani Sefidi¹

1. Department of Physical Chemistry, Electrochemistry Research Laboratory, University of Tabriz2. Engineering Faculty, Department of Materials Science and Nanotechnology,Near East University

摘 要：The camphor sulfonic acid doped polyaniline-WO₃-multiwall carbon nanotube（CSA PANI-WO₃-CNT）ternary nanocomposite was synthesized during in-situ oxidative polymerization and characterized by Fourier transform infrared（FTIR） spectroscopy, Raman spectroscopy, X-ray diffraction（XRD）, Field emission scanning electron microscopy（FESEM）, X-ray photoelectron spectroscopy（XPS）, Transmission electron microscopy（TEM）, and Energy-dispersive X-ray spectroscopy（EDS）. The application of CSA PANIWO₃-CNT ternary nanocomposite was investigated as the photocatalyst in the degradation of methylene blue dye（MB） and as the noble metal-free photoanode in photoelectrochemical water splitting under solar light irradiation. The degradation percentage of MB dye after 60 min illumination by CSA PANI-WO₃-CNT ternary nanocomposite reached 91.40% which was higher than that of pure WO₃（43.45%）, pure CSA PANI（48.4%） and CSA PANI-WO₃ binary nanocomposite（85.15%）. The photocurrent density of indium tin oxide（ITO）/CSA PANI-WO₃-CNT photoanode obtained 0.81 m A/cm² at 1.23 V vs. reversible hydrogen electrode under illumination which was 1.27, 2.13, and 4.26 times higher than that of the ITO/CSA PANI-WO₃（0.64 m A/cm²）, ITO/pure CSA PANI（0.38 m A/cm²）, and ITO/pure WO₃（0.19 m A/cm²）. Also,the applied bias photon-to-current efficiency（ABPE） of ITO/CSA PANI-WO₃-CNT was obtained 0.11%which showed two-fold, four-fold, and five-fold enhancements compared to the ITO/CSA PANI-WO₃,ITO/CSA PANI, and ITO/WO₃, respectively. The electrochemical impedance spectroscopy, as well as the Mott-Schottky results, confirmed the better photoelectrocatalytic activity of ITO/CSA PANI-WO₃-CNT in comparison with ITO/WO₃, ITO/CSA PANI, and ITO/CSA PANI-WO₃. The observed improvement in the photocatalytic and photoelectrocatalytic performances of WO₃ in the presence of CSA PANI is due to the formation of type-II heterojunction between WO₃ and CSA PANI which allows the separation of charge carriers easier and faster. On the other hand, MWCNT addition to the CSA PANI-WO₃ nanocomposite provided the conducting substrate for efficient interfacial charge separation as well as transferring.

关键词：