Photocatalytic hydrogen peroxide production with an external quantum yield of almost 500.

From the perspective of energy and environmental issues, the development of green methods for H2O2 production is demanded as an alternative to the conventional energy-intensive anthraquinone method. Among the candidates, photocatalytic H2O2 production has recently attracted much interest. To withstand the use under harsh conditions, it is desirable that the photocatalyst be composed of robust inorganic materials. However, the external quantum yield (ϕ ex) of H2O2 production by inorganic photocatalysts remains below 20% in most studies. Here we demonstrate that a nanohybrid photocatalyst consisting of antimony-doped SnO2 and ZnO can produce H2O2 with a ϕ ex of ∼500% from O2-saturated ethanol aqueous solution under UV-light irradiation. In the photochemical reactions, the quantum yield is usually far below unity (<100%) due to the rapid recombination of photogenerated charge carriers. Breaking through this limit will pave the way for innovative photochemical reactions with the photocatalytic H2O2 synthesis brought closer to practical application.