9 research outputs found
Photocatalytic solar light H2 production by aqueous glucose reforming
A series of tungsten and nitrogen doped Pt-TiO2
samples were prepared with the aim to extend the TiO2 absorption
to the visible light region and to enhance the separation
efficiency of the photogenerated electron/hole pairs. The physicochemical
features of the powders were characterized by Xray
diffraction (XRD), UV/Vis reflectance spectra, specific surface
area (SSA) determinations, and transmission electron microscopy
(TEM) analyses. The influence of the presence of different doping agents was evaluated, under anaerobic conditions, in
the aqueous photo-reforming of glucose to form H2 at ambient
pressure and temperature under a halogen lamp or natural solar
light irradiation. Arabinose, erythrose, and formic acid were
the main glucose partial oxidation products observed in the
liquid phase, whilst H2 and CO2 were measured in the gaseous
phase. The highest H2 production was observed in the presence
of the Pt-TiO2-W0.25 sample
Photocatalytic formation of H2 and value-added chemicals in aqueous glucose (Pt)-TiO2 suspension
Commercial and home prepared bare and Pt-supported TiO2 samples were used as the photocatalysts for the aqueous photo-conversion of glucose at ambient pressure and temperature. Aerobic and anaerobic conditions were used to study the products of glucose degradation both in the liquid (arabinose, erythrose, gluconic acid, glucaric acid, fructose and formic acid) and gaseous (H2 and CO2) phases. The distribution of these molecules was different in the presence of the various powders, depending on the structural and physico-chemical properties of the materials, and Pt resulted essential for the anaerobic production of H2. The home prepared samples resulted more active than the commercial ones. The rutile and brookite polymorphs were the most active samples both for glucose conversion and H2 formation (about 1700 \u3bcmol of H2 were produced over 7 h of irradiation in the presence of Pt-brookite materials)
CO2 Reduction in Photocatalytic Membrane Reactor: Products Selectivity Study
CO2 Reduction in Photocatalytic Membrane Reactor: Products Selectivity Stud
Cu-substituted lanthanum ferrite perovskites: Preparation, characterization and photocatalytic activity in gas-solid regime under simulated solar light irradiation
LaFeO3 perovskites, both bare and containing 5-40 mol% of Cu(II) substituting Fe(III), have been prepared by the citrate autocombustion synthesis method and used as heterogeneous photocatalysts for the degradation of 2-propanol in gas-solid regime under simulated solar light irradiation. Bare LaFeO3 resulted inactive, whereas Cu(II) containing perovskites oxidized 2-propanol to propanone, and eventually to CO2 and H2O. The photocatalytic activity of the Cu containing LaFeO3 perovskites increased by increasing the Cu amount up to 10 mol% and hence slightly decreased for higher copper contents. The samples were fully characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman and diffuse reflectance (DRS) spectroscopies, X-ray photoelectron spectroscopy (XPS) and photocurrent measurements. The photocatalytic activity was correlated with compositional, structural and morphological features
Selective photocatalytic oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxaldehyde by polymeric carbon nitride-hydrogen peroxide adduct
Polymeric carbon nitride-hydrogen peroxide adduct (PCN-H2O2) has been prepared, thoroughly characterised and its application for selective photocatalytic conversion of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxaldehyde (FDC) in aqueous suspension has been studied. The PCN-H2O2adduct is stable in aqueous suspension under UV and solar irradiation up to 100 \uc2\ub0C. It is also stable up to 200 \uc2\ub0C if heated in air, while at temperatures close to 300 \uc2\ub0C its decomposition takes place. Based on the obtained characterisation data it has been proposed that H2O2attaches to the non-polymerised carbon nitride species and to the heptazine nitrogen atoms, thus producing strong hydrogen bonding within the PCN-H2O2adduct. The blockage of the surface amino-groups in PCN-H2O2by H2O2hinders the interaction of HMF with these sites, which are responsible for unselective substrate conversion. PCN-H2O2, although being less active, possesses a superior selectivity in natural solar light assisted oxidation of HMF to FDC reaching 80% with respect to its thermally etched PCN counterpart, which gives rise to a 40\ue2\u80\u9350% selectivity. We believe that the exceptional performance of the applied photocatalyst in the selective photocatalytic conversion of HMF to a high added value FDC in a green solvent under natural illumination makes a significant contribution to the development of environmentally friendly technologies for biomass valorisation
Corrigendum: Whole-genome landscape of pancreatic neuroendocrine tumours
This corrects the article DOI: 10.1038/nature21063