1. Chromate Reduction on the Novel Hetero-system La2NiO4/TiO2 under Solar Light
- Author
-
H. Lahmar and M. Benamira
- Subjects
Aqueous solution ,Materials science ,Chromate conversion coating ,business.industry ,Non-blocking I/O ,Oxalic acid ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,010309 optics ,chemistry.chemical_compound ,Semiconductor ,Adsorption ,chemistry ,0103 physical sciences ,Direct and indirect band gaps ,Hexavalent chromium ,0210 nano-technology ,business - Abstract
The removal of hexavalent chromium Cr(VI) from aqueous solutions is successfully achieved over the new hetero-system La 2 NiO 4 /TiO 2 at pH~4 under solar light. La 2 NiO 4 was found to be a direct band gap semiconductor with an optical transition of 1.30 eV. The photo-electrochemical characterization of the sensitizer La 2 NiO 4 is undertaken to predict the electrons injection in TiO 2 which acts as electrons Bridge to adsorbed HCrO 4 โ. This compound presents a p-type semiconductor with a flat band potential of 0.18 V SCE - more cathodic than that of TiO 2 . The photoactivity is strongly enhanced in the presence of oxalic acid as hole scavenger. The saturation is due to Cr3+ oxidation by photoholes and the competitive water reduction. The reutilization shows a negligible deactivation effect and the hetero-system could be promising for increasing the quality of water.
- Published
- 2017