Mild ultrasound-assisted synthesis of TiO 2 supported on magnetic nanocomposites for selective photo-oxidation of benzyl alcohol

Abstract

Mild ultrasound-assisted synthesis of TiO2 supported on magnetic nanocomposites for selective photo-oxidation of benzyl alcohol, Applied Catalysis B, Environmental http://dx.doi.org/10. 1016/j.apcatb.2015.10.034 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Photoxidation of Benzyl Alcohol with Heterogeneous Photocatalysts in the UV Range: The Complex Interplay with the Autoxidative Reaction

“…Photocatalysis is a fast and economically attractive option for oxidation reactions. The use of semiconductor photocatalysts for selective organic synthesis has been steadily growing in interest in the last years . TiO 2 , CeO 2 , CdS and their related hybrid materials have been proven as very efficient catalysts for oxidation reactions of alkanes and alcohols .…”

Wheat bran valorisation: Towards photocatalytic nanomaterials for benzyl alcohol photo-oxidation

“…20% at 33% conversion of benzyl alcohol) was achieved for 10%Ti-Bran catalyst with a selectivity of over 60%. Comparatively, the P-25 Evonik titania photocatalyst provided a maximum of 33% yield, with quantitative conversion of starting material (mostly mineralization of benzyl alcohol takes place under the investigated conditions) (Colmenares et al, 2016). Taking into account the titania content in both materials, we can conclude that the designed titania-wheat bran nanocomposites outperform commercial titania nanomaterials in the investigated selective photo-oxidation.…”

“…Among various semiconductorbased photocatalysts, TiO 2 is one of the most attractive photocatalysts owing to its outstanding photocatalytic activity, high thermal and chemical stability, non-toxicity, cost effectiveness and the strong oxidizing power of the photogenerated holes. Massive investigations related to TiO 2 photocatalysts have been reported in different applications in the last decades, including chemicals and fuels production from CO 2 reduction (Adachi et al, 1994;Chen et al, 2015;Yu et al, 2014), decontamination of water (Herrmann et al, 1999;Hoffmann et al, 1995;Yang et al, 2008), organic synthesis (Colmenares et al, 2016;Higashimoto et al, 2009;Hubert et al, 2010;Ohno et al, 2003b) and production of H 2 from water splitting (Chen et al, 2010;Ni et al, 2007). However, the use of pure TiO 2 photocatalyst is limited by its large band gap (3.2eV, anatase crystalline phase) which requires light with wavelength l < 387 nm for the excitation of electrons from the valence to the conduction band, resulting that only 5% of the solar irradiation can be utilized for the photocatalytic process.…”

“…lignin). Photocatalytic oxidation of benzyl alcohol towards benzaldehyde with high selectivity has been reported in recent years (Colmenares et al, 2016;Higashimoto et al, 2009;Li et al, 2012;Marotta et al, 2011;Spasiano et al, 2013), which provide a possible substitution to the traditional synthetic routes -either by benzyl chloride hydrolysis or through oxidation of toluene. A review on the transformation of biomass-derived compounds with heterogeneous photocatalytic nanomaterials was also recently reported .…”

Mechanochemical Synthesis of TiO2 Nanocomposites as Photocatalysts for Benzyl Alcohol Photo-Oxidation

“…In recent years, photocatalysts with TiO 2 coated on magnetic particles have been reported by many researchers [27,28,29], which showed enhanced photocatalytic activities and feasible separation by applying external magnetic field. Ojeda et al reported a maghemite/silica nanocomposites, which were also magnetically separable [30], followed by a report on the incorporation of TiO 2 on maghemite/silica nanocomposites under ultrasounds which exhibited excellent photocatalytic performance in the selective oxidation of benzyl alcohol [31]. …”