title: Aluminum Titania Nanoparticle Composites as Nonprecious Catalysts for Efficient Electrochemical Generation of H2.
abstract: In this paper, we demonstrated, for the first time, aluminum titania nanoparticle (Al-TiO2 NP) composites with variable amounts of TiO2 NPs as nonprecious active catalysts for the electrochemical generation of H2. These materials were synthesized by mixing desired amounts of hydrogen titanate nanotubes (TNTs), fabricated here by a cost-effective approach at moderate hydrothermal conditions, with aluminum powder (purity 99.7%; size 35 μm). The mixture was compacted under an applied uniaxial stress of 300 MPa followed by sintering at 500 °C for 1 h. After sintering had been completed, all TNTs were found to convert to TiO2 NPs (average particle size 15 nm). Finally, Al-xTiO2 NP nanocomposites (x = 1, 3, 5, and 10) were obtained and characterized by scanning electron microscopy/energy-dispersive X-ray, X-ray diffraction, and X-ray photoelectron spectroscopy. The hydrogen evolution reaction (HER) activity of these materials was studied in 0.5 M H2SO4 at 298 K using polarization and impedance measurements. The nanocomposite of chemical composition Al-5% TiO2 NPs showed the best catalytic performance for the HER, with an onset potential (EHER), a Tafel slope (βc), and an exchange current density (j0) of -100 mV (RHE), 59.8 mV decade(-1), and 0.14 mA cm(-2), respectively. This HER activity is not far from that of the commercial platinum/carbon catalyst (EHER = 0.0 mV, βc = 31 mV dec(-1), and j0 = 0.78 mA cm(-2)). The best catalyst also exhibited good stability after 10000 repetitive cycles with negligible loss in current.
authors.affiliation: Materials Science and Engineering Group, Department of Chemistry, Faculty of Science, Taif University , 888 Hawiya, Taif, Saudi Arabia.|Department of Chemistry, Faculty of Science, Ain Shams University , 11566 Abbassia, Cairo, Egypt.
authors.forename: Mohammed A
authors.initials: MA
authors.lastname: Amin
authors.affiliation: Materials Science and Engineering Group, Physics Department, Faculty of Science, Taif University , 888 Hawiya, Taif, Saudi Arabia.|Solid State Physics Department, National Research Center , Dokki, Giza 12311, Egypt.
authors.forename: Emad M
authors.initials: EM
authors.lastname: Ahmed
authors.affiliation: Materials Science and Engineering Group, Department of Chemistry, Faculty of Science, Taif University , 888 Hawiya, Taif, Saudi Arabia.|Chemistry Department, Faculty of Science, Suez Canal University , Ismailia, Egypt.
authors.forename: Nasser Y
authors.initials: NY
authors.lastname: Mostafa
authors.affiliation: Materials Science and Engineering Group, Physics Department, Faculty of Science, Taif University , 888 Hawiya, Taif, Saudi Arabia.
authors.forename: Mona M
authors.initials: MM
authors.lastname: Alotibi
authors.affiliation: Materials Sciences and Technology Division, CSIR-North East Institute of Science and Technology , Jorhat 785006, Assam, India.|Academy of Scientific and Innovative Research, CSIR-NEIST Campus , India.
authors.forename: Gitashree
authors.initials: G
authors.lastname: Darabdhara
authors.affiliation: Materials Sciences and Technology Division, CSIR-North East Institute of Science and Technology , Jorhat 785006, Assam, India.|Academy of Scientific and Innovative Research, CSIR-NEIST Campus , India.
authors.forename: Manash R
authors.initials: MR
authors.lastname: Das
authors.affiliation: Department of Electrochemistry, Corrosion and Materials Engineering, Chemical Faculty, Gdańsk University of Technology , Narutowicza 11/12, 80-233 Gdańsk. Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Wysocka
authors.affiliation: Department of Electrochemistry, Corrosion and Materials Engineering, Chemical Faculty, Gdańsk University of Technology , Narutowicza 11/12, 80-233 Gdańsk. Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Ryl
authors.affiliation: Department of Chemistry, Faculty of Science, Ain Shams University , 11566 Abbassia, Cairo, Egypt.
authors.forename: Sayed S
authors.initials: SS
authors.lastname: Abd El-Rehim
keywords: aluminum; electrocatalysis; hydrogen evolution reaction; nanocomposites; titania nanoparticles