Hydrogen photogeneration using ternary CuGaS2-TiO2-Pt nanocomposites

Abstract

In this contribution we synthesized ternary CuGaS 2-TiO 2-Pt materials. The semiconductor components were surface functionalized with mercapto-alifatic acids to drive their linking and were platinized prior to or after contact between the semiconductors. The corresponding samples were utilized in the photo-production of hydrogen using methanol as a sacrificial agent. The testing under UV and visible illumination conditions together with the calculation of the true quantum efficiency of the process demonstrate the outstanding performance of these ternary materials under sunlight operation. Optimum activity was achieved for samples having a 3 to 5 wt % of the chalcogenide and a selective interaction of the noble metal with the major oxide component. The physico-chemical characterization and particularly the use of photoluminescence spectroscopy showed that photo-activity is controlled by charge separation under illumination, which drives to charge location of electrons and holes in different components of the powders and the efficient use of charge carriers in the chemical reaction.

Effect of Pluronic P103 Concentration on the Simple Synthesis of Ag and Au Nanoparticles and Their Application in Anatase-TiO2 Decoration for Its Use in Photocatalysis

“…The physical-chemical properties of the photocatalysts were also analyzed using XPS. As expected, analysis of the Ti 2p signal ( Figure 11 a) in all samples provides evidence of a Ti(IV) chemical state (Ti 2p3/2 and Ti 2p1/2 binding energy peaking at 458.4 and 464.1 eV for all samples) characteristic of titanium oxides [ 60 , 61 ]. Following the analysis carried out in this work, three characteristic peaks are observed in the O 1s spectra ( Figure 11 b) for all samples.…”

Sunlight-Operated TiO2-Based Photocatalysts

“…A clear comparison has been presented showing that this is the case, for example, for hydrogen photoproduction. In this case, the quantum efficiency values under a 1.5AM solar-type illumination can have a significant contribution from the UV part in several highly-active TiO 2 -based composite photocatalysts [ 12 ], in spite of the fact that the UV part of the sunlight intensity is only around ca. 4%.…”

Photodegradation of Congo Red by Modified P25-Titanium Dioxide with Cobalt-Carbon Supported on SiO2 Matrix, DFT Studies of Chemical Reactivity

“…New photocatalytic materials make use of visible or near infrared light which correspond roughly to 40-45% and 50-55% of the solar light intensity at sea level. For hydrogen photo production, the quantum efficiency values under a solar-type illumination can have a significant contribution from the UV part in several highly-active TiO 2 -based composite photocatalysts [12]. In spite of the fact that the UV part of the sunlight intensity is only ca.…”