Spray-drying of milk for oxygen evolution electrocatalyst and solar water splitting.

The development of efficient and robust electrocatalyst has been the central of the solar water splitting-based hydrogen fuel acquisition. In this work, we reported the use of cow milk, with addition of tetraethyl orthosilicate (TEOS) and melamine, for the synthesis of nitrogen-doped mesoporous carbon microspheres. Due to the large surface and enhanced charge transport behavior, the obtained samples enabled low overpotentials and a small Tafel slope toward oxygen evolution reaction, which were close or comparable to the best OER catalysts of carbon materials reported previously. Further incorporation of this catalyst and a Pt wire to a commercial solar cell, the direct solar-to-hydrogen conversion was realized, with a stability of over 30h.