Search results for "photocatalysi"
showing 10 items of 626 documents
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.
Photocatalytic Nanofiltration Reactors
2021
ChemInform Abstract: Inorganic Materials Acting as Heterogeneous Photocatalysts and Catalysts in the Same Reactions
2016
General considerations on the differences and similarities between heterogeneous photocatalysis and thermal catalysis are presented. Some research papers are reviewed where a reaction has been carried out in the presence of an inorganic material used both as catalyst and photocatalyst. The existing literature often compares catalytic reactions undertaken with the contemporaneous presence of radiation, showing only that photocatalytic reactions can occur under milder experimental conditions and at much lower temperatures. Nevertheless, differences in mechanistic aspects, conversions and selectivities between catalytic and photocatalytic reactions should also be highlighted. These are due to …
2020 Roadmap on two-dimensional nanomaterials for environmental catalysis
2019
Abstract Environmental catalysis has drawn a great deal of attention due to its clean ways to produce useful chemicals or carry out some chemical processes. Photocatalysis and electrocatalysis play important roles in these fields. They can decompose and remove organic pollutants from the aqueous environment, and prepare some fine chemicals. Moreover, they also can carry out some important reactions, such as O2 reduction reaction (ORR), O2 evolution reaction (OER), H2 evolution reaction (HER), CO2 reduction reaction (CO2RR), and N2 fixation (NRR). For catalytic reactions, it is the key to develop high-performance catalysts to meet the demand for targeted reactions. In recent years, two-dimen…
ChemInform Abstract: Coupled Semiconductor Systems for Photocatalysis. Preparation and Characterization of Polycrystalline Mixed WO3/WS2 Powders.
2010
Mixed WO3/WS2 powders were prepared by oxidation of WS2. The physical properties of the samples were characterized by X-ray diffraction, diffuse reflectance spectroscopy, and scanning electron microscopy; they were strongly dependent upon the time and temperature of oxidation. The chemical state and the elemental distribution of the sample surface were investigated by X-ray photoelectron spectroscopy. The photocatalytic results have showed that the aqueous suspensions of the mixed WO3/WS2 systems have significantly higher activities than pure WS2 and WO3 for the photodegradation of phenol. The enhanced performance can be related to the presence of heterojunctions WO3/WS2 on the single parti…
ChemInform Abstract: Green Oxidation of Alcohols to Carbonyl Compounds by Heterogeneous Photocatalysis
2011
High activity of brookite TiO2 nanoparticles in the photocatalytic abatement of ammonia in water
2015
Abstract The effects of the TiO 2 crystal structure and its surface modification with Pt nanoparticles on the photocatalytic oxidation of NH 3 in the aqueous phase were studied with home-made TiO 2 photocatalyst powders synthesized by a thermo-hydrolysis approach that allowed a fine control of the crystallographic phase composition. Ammonia conversion and the selectivity toward mildly oxidized N 2 and highly oxidized nitrite and nitrate anions were monitored during the runs. Pure brookite powders modified by Pt nanoparticles, deposited either from a colloidal suspension or by deposition–precipitation, were found to be the most efficient photocatalysts in NH 3 degradation, with a desired goo…
Photocatalytic degradation of 4-Nitrophenol by g-C3N4-MCy: Mechanism study and kinetic modeling
2021
Abstract A graphitic carbon nitride (g-C3N4-MCy) photocatalyst was prepared by thermal condensation of melamine and cyanuric acid with equal proportions. The photocatalyst was characterized by Fourier transform infrared spectroscopy (FTIR), Specific surface area (SSA), X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), Transmission electron microscope (TEM), and DRS–UV–Vis spectroscopic methods. We studied the photo-degradation kinetics of 4-nitrophenol using a g-C3N4-MCy. Four parameters were applied including initial concentration of 4-nitrophenol, amount of catalyst, dissolved oxygen content, and photon flux. The reaction rate constant was shown to be correlate…
ChemInform Abstract: Advances in Selective Conversions by Heterogeneous Photocatalysis
2010
Selective photocatalytic conversions are offering an alternative green route for replacing environmentally hazardous processes with safe and energy efficient routes. This paper reports the most recent advances in the application of heterogeneous photocatalysis to synthesize valuable compounds by selective oxidation and reduction.