Physical and photoelectrochemical properties of the ilmenite NiTiO3 prepared by wet chemical method and its application for O2 evolution under visible light. (1st March 2018)

• Record Type: Journal Article
• Authors: Boudjellal, L.; Belhadi, A.; Brahimi, R.; Boumaza, S.; Trari, M.
• Is Part Of: Materials science in semiconductor processing. Volume 75(2018)
• Page Start: 247
• Page End: 252
• Publication Date: 2018-03-01
• Subjects: Ilmenite -- NiTiO3 -- Semiconductor -- Photo-electrochemistry -- Oxygen evolution; Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2017.10.043
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: The ilmenite NiTiO3 prepared by wet chemical method is characterized by thermal gravimetry (TG), X-ray diffraction (XRD), FTIR and Scanning Electron Microscopy (SEM). The oxide crystallizes in the hexagonal symmetry with grains size in the range [200–300 nm]. The BET analysis gives a specific surface area of ~ 4 m 2 g −1 . The UV–vis diffuse reflectance analysis gives a direct transition at 2.57 eV well matched to the solar spectrum. The transport properties exhibit n -type semiconductor with an activation energy of 0.11 eV and an electron mobility of 5.82 × 10 −4 cm 2 V −1 s −1 . The physical and chemical characterizations are correlated for the construction of the energy diagram in order to assess the photoelectrochemical properties for the oxygen evolution. The valence band, deriving from O 2- : 2p orbital (2.19 V SCE ), is located above the O2 /H2 O potential (~ 1.5 VSCE ), allowing O2 -evolution upon visible light (15 mW cm −2 ) and the oxide is photocathodically protected against corrosion. An evolution rate of 0.046 mL mg −1 h −1 is obtained within 20 min upon visible light and under optimal conditions (200 mg of catalyst, pH ~ 3 and 50 °C).