Search results for "Solar light"

Rhodamine (B) photocatalysis under solar light on high crystalline ZnO films grown by home-made DC sputtering

2018

Abstract ZnO thin films were deposited by home-made DC sputtering of zinc target under mixed gases (Argon, Oxygen) plasma on glass substrates. Films were deposited by varying oxygen partial pressure (PO2) from 0.09 to 1.3 mbar in the deposition chamber, at a fixed substrate temperature of 100 °C. The samples were characterized by photoluminescence (PL), X-ray diffraction (XRD), optical transmissions (UV–vis), scanning electron microscopy (SEM) and electrical (Hall effect) measurements. The results indicate that by varying the oxygen pressure in the deposition chamber, the films show a precise and well defined photoluminescence emissions for each range of pressure covering almost the entire …

Silver Nanoparticles in Heterogeneous Plasmon Mediated Catalysis

2015

Metallic nanoparticles are considered a new class of heterogeneous photocatalysts due to their ability to absorb solar light and convert it into chemical energy. Here, we focus on the use of silver nanoparticles in light driven catalytic processes. This chapter will start with a brief introduction to the currently available nanocomposites that contain silver nanoparticles. Then, the mechanisms behind the photocatalytic activity of those nanocomposites will be discussed.

GaP/TiO2 Composite Photocatalyst for CO2 Reduction in Gas-Solid Regime under Simulated Solar Light Irradiation

2014

Age‐induced change in the color of the human crystalline lens

2011

Purpose To determine the chromatic coordinates of different human crystalline lenses to analyze the age-induced change in the color of the crystalline. Methods The spectral transmission of nine human crystalline lenses of different ages were measured by using a Perkin-Elmer 800 UV/VIS spectrophotometer. Using these data we calculated the chromatic coordinates of each crystalline lens for both solar and incandescent illumination. The study adheres to the tenets of the Declaration of Helsinki for Research Including Human Subjects and was approved by the Institutional Review Board. Results The results show a greater saturation of color with the increase of age. In principle, the change tends t…

Photocatalytic Solar Light H 2 Production by Aqueous Glucose Reforming

2018

Semiconductor @ sensitizer composites for enhanced photoinduced processes

2021

Abstract This Chapter provides an overview of common procedures used for the preparation, characterization, and exploration of photocatalytic properties of composite materials based on inorganic semiconductors in combination with sensitizers, such as porphyrins, phthalocyanines, and related macrocyclic compounds as promoters of photoinduced processes. In this context the advantage of hybrid photocatalysts, obtained by impregnation of photosensitizers onto the surface of different semiconductors, designed for improving a choice of diverse reactions has been demonstrated, highlighting innovative aspects that contribute to better sustainability of the photocatalytic processes. Mechanistic deta…

Numerical analysis of light soaking phenomenon in Ruthenium based Dye Sensitized Solar Cells

2017

Dye Sensitized Solar Cells (DSSCs) are widely considered one of the most promising third generation photovoltaic devices, especially thanks to their relatively low cost if compared to conventional solar cells. An interesting phenomenon affecting such devices is the so-called light soaking effect, consisting in the increase of cell main electrical parameters after the exposition to solar light. In this work, starting from the experimental characterization carried out on Ruthenium-based DSSCs, we report on a series of numerical analysis performed to better describe the above-mentioned light soaking effect in order to show the relationship between such phenomenon and the main physical paramete…

Facile preparation of CuBi2O4/TiO2 hetero-systems employed for simulated solar-light selective oxidation of 4-methoxybenzyl alcohol model compound

2023

The selective photocatalytic oxidation of organic substances is today considered one of the green techniques to synthesize important starting materials in different technological applications. This work reports an efficient, simple and cheap strategy for the synthesis of a new photocatalytic CuBi2O4-TiO2 (CBO/TiO2) heterosystem at room temperature. The prepared powders were characterized by X-ray diffraction (XRD), UV–Vis diffuse reflectance spectra (DRS), field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and electrochemical measurements. The photocatalytic activity was evaluated by performing a probe reaction, namely the partial oxidation of 4-me…

Selective aqueous oxidation of aromatic alcohols under solar light in the presence of TiO2 modified with different metal species

2022

AbstractA set of metals modified TiO2 photocatalysts were prepared starting from titanium tetraisopropoxyde and different metal precursors to study the influence of the addition of the various foreign agents on the physico-chemical and photocatalytic properties of the catalysts. The powders were characterized by X-ray diffraction, Raman spectroscopy, specific surface area measurements, scanning electron microscopy, energy dispersive X-ray spectroscopy, UV–Vis diffuse reflectance spectroscopy, photoluminescence, temperature programmed desorption after CO2 adsorption. The photocatalytic activity was evaluated using as probe reactions the partial oxidation of three aromatic alcohols: benzyl al…

Efficient H2 production by photocatalytic water splitting under UV or solar light over variously modified TiO2-based catalysts

2019

Abstract This paper focused for the first time on the comparison between three different approach to modify the chemico-physical properties of TiO2-based photocatalysts and their effect in the H2 production by photocatalytic water splitting both under UV and solar light irradiation, under the same experimental conditions. The application of pulsed laser irradiation to aqueous TiO2 suspensions (first approach) induced structural transformations both on the bulk and on the surface of TiO2, boosting the H2 production, under UV light irradiation, of almost three times (20.9 mmol/gcat·h) compared to bare TiO2 (7.7 mmol/gcat·h). The second strategy was based on a templating method to obtain TiO2 …