Catalysts are decisive for the reduction of overpotentials at the photoelectrode/electrolyte interface, since they significantly improve the charge carrier transport across the semiconductor/electrolyte interface (SEI). Platinum is the catalyst mostly used for the hydrogen evolution reaction (HER) because it has moderate binding and absorption energies for protons and hydrogen, respectively, which leads to a high turnover frequency in the HER. However, the high cost of Pt limits its widespread application. In order to reduce the costs, expensive noble metal catalysts must be replaced by cheap, environmentally uncritical and earth abundant catalysts.