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Über dieses Buch

Karl Striegler investigates novel materials for photocatalytic hydrogen evolution from water. Graphitic Carbon Nitrides are an interesting class of materials with a structure close to graphite. For overcoming certain limitations, the author used different approaches to functionalize the basic material. He deposited nanoparticles to enhance the catalytic activity and used copolymerization as well as sensitizing to increase the amount of harvested light.

Inhaltsverzeichnis

Frontmatter

1. Introduction and Objective

Abstract
Hydrogen is an important basic chemical. It is widely used in industry for example methanol synthesis, the Haber-Bosch process, hydrogenation reactions or the Fischer-Tropsch process. Furthermore, over the last decades it has become evident that CO2 is a greenhouse gas, which is presumably responsible for global warming. Thus and due to its limited availability, humankind will have to change from fossil fuels as primary energy sources to regenerative energy sources. H2 is promising candidate as an energy carrier. Lately, research is focusing on pollution free hydrogen generation by photocatalytic water splitting or photoelectrolysis of water. These methods provide sustainable energy.
Karl Striegler

2. Literature Overview

Abstract
Hydrogen is required for several applications. Besides classic chemical use like the Haber-Bosch process, coal liquefaction or for hydrogenation, it is to be considered as an energy carrier.[1,2] Ever since hydrogen has been used on a large scale, there has been the need for an efficient, cheap hydrogen production.[3] In the past, numerous ways of hydrogen production were developed. Still, fossil fuels are regarded to be the prerequisite for steam reforming.[4] Furthermore, partial oxidation or coal gasification are also depending on fossil fuels.
Karl Striegler

3. Experimental Section

Without Abstract
Karl Striegler

4. Results and Discussion

Abstract
For a modification of graphitic carbon nitrides there are two starting compounds which are suitable for a sufficient synthesis of the semiconductor. One aim of the work was to analyze and improve the graphitic carbon nitride described and investigated by several groups so far. Pure g-C3N4 was synthesized according to well-known procedures as described in section 3.3.1 from melamine (MA) or dicyandiamide (DCA) and differences in physical and chemical properties as well as their catalytic activity were studied. XRD pattern and UV/Vis spectra are depicted in Figure 4-1 and Figure 4-2 indicate that the catalysts derived from two different precursors do not vary strongly.
Karl Striegler

5. Conclusion and Outlook

Abstract
In the presented thesis several modification of the semiconductor graphitic carbon nitride were realized. The aim of this thesis was the analysis of the activity of modified photocatalyst towards photocatalytic hydrogen evolution from water. Different characterization techniques were used to clarify the nature of the resulting changes. In order to modify the basic material, several synthesis routes were chosen to establish a sufficient in-situ and post-synthesis functionalization. Thus, three different approaches were examined.
Karl Striegler

Backmatter

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