Fig. 5: The demonstration and performance of photocatalysis-electrocatalysis relay water splitting.
From: Tunable multi-electron redox polyoxometalates for decoupled water splitting driven by sunlight
a Schematic diagram showing the role of POMs as redox mediators in the constructed photocatalysis-electrocatalysis relay system using BiVO4 photocatalyst. CB represents conduction band. VB represents valence band. ∆E represents potential difference between the redox medium and conduction band of semiconductor. Esolar represents storage of solar energy. PEM represents proton exchange membrane. Ox-POM represents oxidation states polyoxometalates. Re-POM[H] represents reducetion states polyoxometalates with coupled protons. b Investigation of photocatalytic O2 evolution and electrons transfer numbers of 1 mM {P2W17V} and {P2W15V3} in 1 M Na2SO4 solutions (pH = 3, 150 mL; BiVO4: 100 mg, stirring speed: 500 rpm) under 300 W Xe lamp with cut filter (λ ≧ 420 nm). c Long-term photocatalysis-electrocatalysis relay testing of 5 mM {P2W17V} and {P2W15V3} redox mediators in 1 M Na2SO4 solutions (pH = 3, 100 mL; BiVO4: 300 mg) and the related H2 collection over 12 hours (electrochemical cell resistance value: 125 ± 5 mΩ).
