Light Illuminated α−Fe2O3/Pt Nanoparticles as Water Activation Agent for Photoelectrochemical Water Splitting

The photoelectrochemical (PEC) water splitting is hampered by strong bonds of H 2 O molecules and low ionic conductivity of pure water. The photocatalysts dispersed in pure water can serve as a water activation agent, which provides an alternative pathway to overcome such limitations. Here we report that the light illuminated α−Fe 2 O 3 /Pt nanoparticles may produce a reservoir of reactive intermediates including H 2 O 2 , ·OH, OH − and H + capable of promoting the pure water reduction/oxidation half−reactions at cathode and highly photocatalytic−active TiO 2 /In 2 S 3 /AgInS 2 photoanode, respectively. Remarkable photocurrent enhancement has been obtained with α−Fe 2 O 3 /Pt as water activation agent. The use of α−Fe 2 O 3 /Pt to promote the reactivity of pure water represents a new paradigm for reproducible hydrogen fuel provision by PEC water splitting, allowing efficient splitting of pure water without adding of corrosive chemicals or sacrificial agent.