Enhanced oxygen evolution on visible light responsive TaON photocatalysts co-loaded with highly active Ru species for IO₃⁻ reduction and Co species for water oxidation

Abstract

Loading an appropriate cocatalyst significantly enhances the activity of semiconductor photocatalysts in both conventional one-step water splitting and Z-scheme-type water splitting with a redox couple.

Mimicking Natural Photosynthesis: Solar to Renewable H2 Fuel Synthesis by Z-Scheme Water Splitting Systems

“… 33 It was recently revealed that the Ru(OH) x Cl y species obtained by the calcination of RuCl 3 · n H 2 O at or below 200 °C showed a much higher activity for IO 3 – reduction than conventional RuO 2 , while the Ru(OH) x Cl y species rarely catalyzed water oxidation. 137 Figure 52 shows current–potential curves for the TaON electrodes loaded with Ru species at various temperatures ( x ) in a Na 2 SO 4 aqueous solution containing IO 3 – (1.0 mM) under dark conditions. XPS analysis indicated that the partially hydroxylated Ru species, e.g., Ru(OH) x Cl y , were loaded onto TaON by the wet-impregnation process followed by calcination at relatively low temperatures (∼200 °C), whereas the calcination at higher temperatures resulted in the formation of conventional RuO 2 .…”

Enhanced water splitting through two-step photoexcitation by sunlight using tantalum/nitrogen-codoped rutile titania as a water oxidation photocatalyst

“…This is because the cocatalyst improves the selectivity for forward reactions while suppressing undesirable backward reactions. 5,6,[32][33][34] As an example, Domen et al reported that a RuO 2 cocatalyst on TaON promotes both the reduction of IO 3…”

“…33 Abe et al developed a RuO 2 cocatalyst that is active during the selective reduction of IO 3 À and also improves O 2 evolution when used as a co-modier for a cobalt-based water oxidation cocatalyst. 34 Because the effects of loading cocatalysts on rutile TiO 2 : Ta,N photocatalysts have not yet been investigated in detail, the activity increases provided by such cocatalysts can likely still be signicantly improved.…”

Photoelectrochemical CO2 Reduction to Formate with the Sacrificial Reagent Free System of Semiconductor Photocatalysts and Formate Dehydrogenase

“…To develop the effective light‐driven CO 2 reduction to formate with the coupling the photoreduction of BP with dye and FDH, development and exploration of photocatalytic materials with highly photosensitizing function and tolerance against irradiation are necessary factors. Among various photocatalytic materials, metal oxide based semiconductor photocatalysts such as TiO 2 are widely used in the hydrogen production due to the light‐driven water splitting . Some studies on light‐driven hydrogen production with the system of semiconductor photocatalyst (TiO 2 , CdS, CdSe quantum dots and so on) and hydrogenase have been reported.…”