Environment-friendly hydrogen: Utilizing solar energy for water splitting

• Max Planck scientists evaluate the destruction of photo-electrodes for water splitting as well as publish their current lead to ACS Applied Energy Materials

A photo-electrode is a solar cell as well as an electrolyser combined in one material. Solar power is converted to split water right into hydrogen and also oxygen, therefore producing eco-friendly hydrogen useful as gas for various applications. Considering that the initial advancements in the 1970s, the research has gained substantial momentum in the last decade, as record performances were reported in various products systems. "As the efficiency of photo-electrodes remain to boost, the traffic jam has become their minimal stability for sensible use in industry.", describes Dr. Siyuan Zhang, researcher as well as initial author of the current publication. "We created a lit up scanning circulation cell to be able to analyse for the very first time the product's deterioration in operando." Zhang as well as his associates at the Max-Planck-Institut für Eisenforschung, the Helmholtz-Zentrum Berlin für Materialien und Energie (HZB), the Helmholtz-Institut Erlangen-Nürnberg for Renewable Energy and also the University of Freiburg published their current searchings for in the journal ACS Applied Energy Materials.

MPIE has a history of creating scanning circulation cell (SFC) techniques, started from previous group leader Prof. Karl Mayrhofer, currently director at the Helmholtz-Institut Erlangen-Nürnberg for Renewable Energy, that combined SFC to a mass spectrometer to examine corrosion. "Our newest innovation, brightened SFC, incorporates the SFC with a solar simulator, which opens up an entire new measurement to investigate corrosion sensations set off by light, labelled photo-corrosion.", states Prof. Christina Scheu, who heads the independent research study team "Nanoanalytics as well as Interfaces" at the MPIE.

The scientists used extremely reliable BiVO4 photo-electrodes provided by the HZB. The inquiry was which aspect from the binary oxide BiVO4 corrodes much faster, and also how procedure conditions can affect their stability. "Our findings show that the electrolyte plays an essential duty in the stability as well as nanometre-sized collections enhanced in Vanadium discovered within the photo-electrode liquify preferentially.", clarifies Zhang, who partnered with Andrea Mingers from the MPIE group "Electrocatalysis" to do these experiments. The MPIE scientists combined the SFC with the MPIE's transmission electron microscopy and also atom probe tomography centers to associate the structural information with the product's chemistry. In close interaction with Dr. Baptiste Gault, head of the "Atom Probe Tomography" team and Se-Ho Kim, PhD researcher in the group, the researchers were able to use aberration-corrected electron microscopy and also atom probe tomography for the very first time on this beam-sensitive materials.

This mix of different techniques provides a comprehensive view on the corrosion of the photo-electrodes. The scientists are now heading to layout catalyst finishings to shield the photo-electrodes from the electrolyte and hence inhibit their deterioration. Being able to increase the life time of photo-electrodes leads the way for their usage in industry and hence for a sustainable hydrogen manufacturing.