WB crystals with oxidized surface as counter electrode in dye-sensitized solar cells

Tungsten boride (WB) crystals, whose surface tends to be oxidized when exposed to air, were demonstrated to have a comparable activity to platinum as counter electrode material in dye-sensitized solar cells. The synergistic effect of both catalytically active surface layer WOx and electronically conductive internal WB is considered to be responsible for the high activity of the WB crystals.