No abstract

No abstract

No abstract

LaFexNi1−xO3 perovskite oxides were prepared by the sol–gel method under various conditions, including different pH values (pH 0 and pH 7) and different calcination temperatures (500–800 °C) as well as different Fe/Ni ratios (1/9, 3/7, 5/5, 7/3, 9/1). The samples were examined by XRD, DRS, BET, and SEM to reveal their crystallinity, light-absorption ability, specific surface area, and surface features, respectively. The photocatalytic Fenton reaction was conducted using various LaFexNi1−xO3 perovskite oxides to decompose the methylene blue molecules. Accordingly, the synthesis condition of pH 0, calcination temperature at 700 °C, and Fe/Ni ratio = 7/3 could form LaFe0.7Ni0.3O3 perovskite oxides as highly efficient photocatalysts. Moreover, various conditions during the photocatalytic degradation were verified, such as pH value, catalyst dosage, and the additional amount of H2O2. LaFe0.7Ni0.3O3 perovskite oxides could operate efficiently under pH 3.5, catalyst dosage of 50 mg/150 mL, and H2O2 concentration of 133 ppm to decompose the MB dye in the 1st order kinetic rate constant of 0.0506 s−1.

Photocatalytic water splitting is a promising approach to converting solar energy into green hydrogen. As an effective photocatalyst, Rh x Cr2–x O3/SrTiO3 has been widely studied for water splitting, mainly synthesized using SrCl2 molten salt as the reaction media. This research systematically studied the effect of molten salts and Al doping in order to test and integrate the combinatorial effect of the modifications of SrTiO3-based catalysts. A series of SrTiO3 and Al-doped SrTiO3 (Al:SrTiO3) were synthesized by the flux method with three molten salts (NaCl, KCl, and SrCl2·6H2O) at different annealing temperatures (900 and 1000 °C). Cocatalyst, Rh x Cr2–x O3, was loaded on the surface of Al-doped SrTiO3 by impregnation and photodeposition methods for comparison. The photocatalytic performance of overall water splitting was evaluated in pure water under UV and AM 1.5G simulated sunlight. A significant improvement in photocatalytic activity was observed in Al-doped Rh x Cr2–x O3/SrTiO3. Especially Al-doped Rh x Cr2–x O3/SrTiO3 synthesized by KCl molten salt showed the highest hydrogen evolution rate with the synergy effect of molten salt and Al doping. Furthermore, hydrogen evolution rates were further enhanced by loading core–shell Rh x Cr2–x O3 using in situ photodeposition instead of impregnation, reaching 784 and 431 μmol h–1 g–1 H2 under 365 nm UV light and AM 1.5G irradiation, respectively.