Artificial photosynthesis: development of Tandem systems for hydrogen production from water and sunlight

Abstract

Solar energy is the most abundant, clean and renewable source with real prospects for global energy maintenance. Among the possibilities of using solar energy, the reaction of artificial photosynthesis to the generation of H2 fuel is considered the most promising strategy. However, most semiconductors with suitable band structures to split water into H2 e O2 absorb only UV light (~4%) and the development of efficient and robust semiconductor based-photocatalysts with suitable band structures to absorb visible light (~44%) for the artificial photosynthesis remains a great challenge and a remarkable task. Recently, Tandem junction of two semiconductor materials, with adequate electronic and structural properties for the reaction of artificial photosynthesis, has been considered a promising strategy to overcome the challenges of the reaction. In this way, this project aims to develop semiconductor materials with adequate electronic properties to absorb visible light and high stability in aqueous medium for the formation of Tandem junctions for the artificial photosynthesis reaction. Tandem junctions system will be prepared by a modified magnetron sputtering deposition method. The magnetron sputtering is a physical vapor deposition method, which does not use reducing agents, surfactants or stabilizers to form the junctions, which is highly desired. The morphological, electronic and structural properties of the materials will be investigated using advanced techniques such as X-ray Absorption Spectroscopy (XAS), X-ray Emission Spectroscopy (XES), X-Ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Electrochemical Impedance spectroscopy (EIS), UV-Vis spectroscopy, Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). (AU)