TiO2ZnO photocatalysts synthesized by sol–gel auto-ignition technique for hydrogen production

• Published in: International journal of hydrogen energy 2017-02, Vol.42 (8), p.5016-5025
• Main Authors: Al-Mayman, Sulaiman I., Al-Johani, Meshal S., Mohamed, Mohamed Mokhtar, Al-Zeghayer, Yousef S., Ramay, Shahid M., Al-Awadi, Abdulrahman S., Soliman, Moustafa A.
• Format: Article
• Language: English
• Subjects: Hydrogen production; Photo-catalysts; TiO2–ZnO; Water splitting
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2016.11.149

The present work investigates Zn doped TiO2 (1.0, 5.0, 10.0, 12.0 and 30.0 wt.% Zn) photo-catalysts; prepared by sol–gel auto-ignition method, which were systematically investigated to configure their structural, surface, optical and morphological properties via using X-ray diffractometer (XRD), Scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX), Fourier Transform Infrared spectrometer (FTIR), and UV–Vis spectrophotometer. The photocatalytic H2 evolution using the TiO2ZnO suspensions was evaluated in a 25 vol.% aqueous ethanol medium using UV illumination (Hg lamp λ = 254 nm, 2.2 mW/cm2). The Zn+2 concentrations utilized to prepare TiO2ZnO nanocomposites were found to have significant effects on specific surface areas, energy band gaps (Eg), efficient separation of charged pairs and thus affected the photocatalytic performances. The photocatalytic activity of the TiO2–10 wt.% ZnO composite has reached an optimal H2 production of 1048 μmol h−1 exceeding those of the pure TiO2 (151 μmol h−1) and TiO2 P25 (595 μmol h−1) photocatalysts. [Display omitted] •Synthesizing Zn doped TiO2 via sol–gel auto-ignition method.•10%ZnTiO2 has indicated the highest H2 production of 1048 μmol h−1.•Eg, SBET and light absorption are main factors affected the photoactivity.•Increasing the Zn conc. over 10% induces defects in TiO2 structure.