The synthesis of ZnO/SrTiO3 composite for high-efficiency photocatalytic hydrogen and electricity conversion

Heterogeneous ZnO–SrTiO₃ nanocomposites were synthesized via a facile hydrothermal method. The highest H₂ production rate, 1317.44 μmol g^?1 within 5 h under solar-light irradiation was achieved for the Zn/Sr ratio of 9:1 of the ZnO–SrTiO₃. More interestingly though the ZnO–SrTiO₃ is a semiconducting system, it could be used as an electrolyte in the low temperature solid oxide fuel cell without electronic conducting short circuiting problem. This device displayed an open circuit voltage of 1.14 V and reached the maximum power density of 564 mW cm^?2 at 550 °C. These results are attributed to the enhanced separation of the charge-hole pairs by the heterogeneous structure of ZnO–SrTiO₃ nanocomposites, which possess obvious both heterogeneously ionic and semiconduction. This new discovery indicates a good promising candidate for both solar and hydrogen energy conversions.