Project Details
Projekt
Zn-doped Gallium Oxynitride Nanoparticles as Efficient Photocatalyst for Water Splitting
Subject Area
Solid State and Surface Chemistry, Material Synthesis
Synthesis and Properties of Functional Materials
Synthesis and Properties of Functional Materials
Term
from 2015 to 2020
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 279227197
We want to produce inorganic materials based on zinc-doped gallium oxynitride with improved photocatalytic activity in the visible regime and extended lifetime. The only rare element in the materials system, Ga, is as abundant as Li, and a byproduct of the aluminum metal production. The material system has little hazardous potential and is sufficiently stable in aqueous media. In contrast to conventional synthesis routes in the liquid phase, highly crystalline nanoparticles will be synthesized in the gas phase (chemical vapor synthesis, CVS) allowing us to decouple thermal post-treatment to anneal defects from agglomeration. Light absorption and charge carrier generation will be optimized by size effects and doping, charge carrier separation by low defect density and band alignment through microstructural variations. The large surface-to-volume ratio provides sufficient area for active sites for efficient photocatalytic activity. We consider zinc-doped gallium oxynitride a promising system, which belongs to the most active systems reported in literature. As key challenges we have identified the production of GaN from an inexpensive source such as Ga(acac)3, the control of local (dopants) and microstructure (dopants, core-shell, composites), and the development and optimization of efficient noble metal-free co-catalysts. We want to exploit the advantages of the CVS process and the step-wise photodeposition of novel ternary mixed oxides to meet these challenges and use detailed characterization of structure and photocatalytic activities to solve them. Especially, the quantitative determination of crystallinity and agglomeration and the correlation with photocatalytic activity combined with the comprehensive spectroscopic characterization (photoelectron spectroscopy, low-energy ion scattering, photocurrent spectroscopy) will allow us to assess the role of defects and to generate quantitative structure-property correlations.
DFG Programme
Priority Programmes
