Synthesis of AMoO4 (A = Ca, Sr, Ba) photocatalysts and their potential application for hydrogen evolution and the degradation of tetracycline in water

Alkaline earth metal molybdates AMoO(4) (A = Ca, Sr, Ba) were synthesized by the traditional solid-state reaction. The structural, morphological, textural and optical properties of metal molybdates were obtained by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmet-Teller (BET) method, diffuse reflectance UV-vis spectroscopy (UV-vis DRS), and photoluminescence spectroscopy (PL). Electrochemical characterization through OCP and EIS measurements was performed to elucidate the photoresponse and electrical properties of metal molybdates. Energy band diagrams obtained by theoretical calculations and experimental data revealed that the synthesized molybdates present convenient band positions to be used in photocatalytic processes. For this reason, these compounds were tested as catalysts in photoinduced processes such as hydrogen production and tetracycline degradation. Accordingly to results, the studied molybdates were able to produce hydrogen (similar to 240 mu mol g(-1) h(-1)) under UV light irradiation and also these materials provoked the degradation of tetracycline (85% in pure water and 97% with the addition of H2O2). In conclusion, CaMoO4, SrMoO4, and BaMoO4 are suitable photocatalysts for water splitting and degradation of organic compounds. (C) 2017 Elsevier B.V. All rights reserved.