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In this study, mesoporous Cu Fe/silicate catalysts were obtained from a simultaneously mixing the NaOH and metal-ion solution to sodium silicate solution and a hydrothermal treatment under alkaline condition without using any organic template. During hydrothermally reaction, the amorphous metal-silicate would reconstruct and formation of the mesostructured Cu Fe/silicate. At appropriate pH values, the silicate species can strongly bind with the Cu2+ ions to form the stable Cu Fe/silicate, and the [Cu2+] in the final filtrated solution is lower than the effluent standard in Taiwan (1.0 ppm). To find the appropriate synthetic parameters, the effects of the pH value, metal to silicate ratio, and the hydrothermal treatment time on the surface areas and mesostructure of the resulted Cu Fe/silicates were discussed in detail. In practice, the mesoporous Cu Fe/silicate catalyst with high surface area of 547 m2g-1 demonstrated a high methanol conversion within 1 h up to >99% at 180 °C to be used as high-performance catalysts for steam reformer of methanol. • Mesoporous Cu Fe/silicate catalysts with high surface area of 547 m2g-1 were obtained. • The [Cu2+] in the final filtrated solution is lower than 1.0 ppm. • The Cu Fe/silicate catalysts demonstrate high methanol conversion up to >99% at 180 °C. [ABSTRACT FROM AUTHOR]

The electronic and optical properties of Fe or/and Ni (co)doped anatase and rutile TiO 2 were investigated using the spin-polarized density functional theory. Our calculated results indicate that the synergistic effect of (Fe + Ni) codoping can lead to a band gap narrowing and the hybridized states of Fe 3 d and Ni 3 d appearing in the forbidden gap, which enhances greatly the optical absorption of TiO 2 nanomaterials from the ultraviolet-light to the infrared-light region and reduces the recombination of photogenerated electron–hole pairs. In particular, (Fe + Ni) codoping can improve greatly the infrared-light absorption of TiO 2 nanomaterials. Furthermore, the researches of electronegativity show that (Fe + Ni)-codoped TiO 2 system has a stronger redox power for hydrogen generation by photocatalytic water splitting compared with pure, Fe-doped, and Ni-doped TiO 2 systems. These results lead to an outstanding solar energy photocatalytic water splitting for hydrogen generation in (Fe + Ni)-codoped TiO 2 photocatalyst. [ABSTRACT FROM AUTHOR]

Abstract: The electronic and optical properties are studied using the density functional theory in (Si,Fe)-codoped anatase TiO2. The calculated results suggest that the synergistic effects of (Si,Fe) codoping can effectively induce the redshift of optical absorption edge, which leads to higher visible-light photocatalytic activity for hydrogen production by water splitting than pure anatase TiO2. To verify the reliability of our calculated results, nanocrystalline (Si,Fe)-codoped TiO2 is synthesized by a sol-gel-solvothermal method, and excellent absorption performance and photocatalytic activity for hydrogen production by water splitting are observed in our experiments. [Copyright &y& Elsevier]