Morphostructural study of some graphene-based aerogels for sensors fabrication

This paper presents a detailed study of the feature-rich essential properties of the family of two-dimensional graphene flakes, as well as the preparation and properties of graphenebased aerogels. The usefulness of Raman spectroscopy, a versatile tool used to identify and characterize the chemical and physical properties of these graphene flakes and their composites is clearly stated. Furthermore, strategies for the preparation of bulk graphene-based aerogels are also discussed. The properties of nanocomposites were analyzed using XRD and SEM combined with micro Raman spectroscopy, which provides structural and optical information

Preliminary water splitting studies on Ag and graphite modified porous structures, as such or decorated with Pt particles

Porous materials were obtained using polyether foam modified with Ag nanowires and graphite paste. Some of those modified porous structures were decorated with Pt particles via double step chronoamperometry. All porous materials were investigated in terms of their electrocatalytic activity for the oxygen and hydrogen evolution reactions (OER and HER) in alkaline medium, after they were inserted into supports made from sintered graphite (for the OER experiments) or Ag wire (for the HER experiments). Electrochemical stability tests were also performed. The results of the OER and HER experiments show that the most catalytically active porous structure is the one modified with graphite paste and Pt particles. Stability tests data show that the porous electrode based on this structure is very stable

COMPARATIVE STUDY REGARDING THE CHEMICAL COMPOSITION OF CRAFT BEER

Since the Middle Ages, after the settlement of the Saxons in Transylvania, the beer arrives first timidly and later by force in the Romanian countries. This paper`s aim is to presenta study on how to prepare homemade beer and its chemical composition

The influence of cadmium precursors upon PdS/Zn1-XCXS photocatalysts efficiency in watersplitting reaction

Photocatalysts based on hexagonal cadmium sulfide have been hydrothermally synthesized using crystalline zinc sulfide as sulfide source, and metal nitrates, acetates, chlorides and sulfatesas cadmium sources. The powders have been characterized by X-Ray Diffraction (XRD), UV-VIS Diffuse Reflectance Spectroscopy (DSR)and Energy-Dispersive X-ray Spectroscopy (EDX). Further experiments of photocatalysis in aqueous solution of sulfide and sulfite for hydrogen evolution, were conducted. The samples were irradiated by monochromatic blue light, generated by an LED. From these experiments it was concluded that the presence of sulfate and acetate anions in the system results in more performantphotocatalysts than the presence of nitrate and especially chlorideanions

A low cost linear parabolic concentrator system-photoreactor for photocatalytic processes that uses natural solar light

PdS/CdS based photocatalysts exhibit high efficiency in water splitting reaction. Due to the fact that the band gap value of CdS is 2.4 eV, the photocatalytic process may be performed using visible light at temperatures between 20 and 80°C. From our previous work we noticed that the yield of water splitting process, using this type of photocatalysts increases with the increase of temperature from 20 to 60°C. To increase the temperature of the photocatalystsuspension at higher values than the environment temperature, an irradiance greater than 1000 W/m2 is needed. In this paper we present the design and construction of an inexpensive solar collector –photoreactorassembly, by which the optimal temperature of photocatalystsuspension can be maintained,even in low solar irradiance conditions