Robust tungsten oxide nanostructure for efficient photoelectric conversion and hydrogen evolution

Solar energy is sustainable and much more abundant than other energy sources, which is considered as the most promising energy source for the future. The conversion of solar energy directly into hydrogen is an effective and promising solution to intermittency of solar energy, simultaneously addressing effective storage and transport problem. Here, we present W18O49 nanowires (WO-NWs) tailored carbon electrodes to enhance hole extraction of CsPbBr3 perovskite solar cells (PSCs) and finally achieve a champion efficiency of 9.17% with open circuit voltage (Voc) of 1.592 V. Meanwhile, we use Ru doped W18O49 (Ru-WO) for robust hydrogen evolution reaction (HER) catalysts, yielding an onset overpotential of 32 mV, Tafel slope of 34 mV dec-1 and exchange current density up to 1.93×10-2 mA cm-2. Moreover, Ru-WO demonstrates excellent operation stability and steady current density up to 500 mA cm-2 over 50 h. The rapid development of CsPbBr3 PSCs with ultra-high Voc and robust HER catalysts makes them highly promising for single-junction solar cell-driven water splitting.