Hydrogen and Oxygen Evolution Photocatalysts Synthesized from Strontium Titanate by Controlled Doping and Their Performance in Two-Step Overall Water Splitting under Visible Light

Abstract

A visible-light-induced two-step overall water splitting was achieved by combining two types of photocatalysts prepared by introducing foreign elements into the identical mother structure with a controlled electronic band structure. Strontium titanate (SrTiO 3 ) was selected as the mother structure and was doped with either vanadium (and sodium) or rhodium to introduce visible light sensitivity. By utilizing these two types of SrTiO 3 -based photocatalysts, simultaneous liberation of hydrogen (H 2 ) and oxygen (O 2 ) with a molar ratio of ∼2:1 was achieved in the presence of iodate ion (IO 3 − )/iodide ion (I −

Enhanced Visible-Light-Sensitive Two-Step Overall Water-Splitting Based on Band Structure Controls of Titanium Dioxide and Strontium Titanate

“…Konda et al reported the existence of two different doped Rh species as mentioned above is responsible for this spectral pattern [23]. The absorption with a peak occurring at ~600 nm ) and O 2p orbitals to form the VB, resulting in a negative-potential shift of the VB top, which we confirmed in our previous study [19]. After depositing either Pt or Ru onto Cr,Ta-TiO 2 or Rh-SrTiO 3 , respectively, the absorption over a wider wavelength region (>400 nm) clearly increased, indicating the successful deposition of Pt or Ru.…”

“…We repeatedly deaerated this system to a final pressure of 2.5 Pa and then introduced argon gas into the system in the same way. For these reasons, we considered that the detection of N 2 originated from the intruded air from outside, and the effect of residual O 2 (and N 2 ) in water was possibly excluded [19] …”

Hydrogenated TiO2/SrTiO3 porous microspheres with tunable band structure for solar-light photocatalytic H2 and O2 evolution

“…The apparent quantum yield decreases with increasing incident light wavelength. This indicates that the water-splitting reaction over the samples is associated with the DRS absorption spectra [44]. Compared with other typical TiO2/SrTiO3 nanostructures with different morphologies [26,[30][31][32][33][34], the H-TiO2/SrTiO3 heterostructured porous microspheres present much higher photocatalytic activity.…”

Hydrogen Generation through Solar Photocatalytic Processes: A Review of the Configuration and the Properties of Effective Metal-Based Semiconductor Nanomaterials

“…Nevertheless, "metal-semiconductor" heterojunctions mostly provide photoactivation under light irradiation with wavelengths shorter than 400 nm. Amongst recently-developed "metal-semiconductor" heterojunctions with a narrow band gap and band edges suitable for water photosplitting, Pt/PbBi 2 Nb 2 O 9 [42], (V,Rh)/SrTiO 3 [43], (Zn,Rh,Cr)/Ga 2 O 3 [41], (La,Rh,Au)/SrTiO 3 [44], Au/CeO 2 [45], (Mo,Au)/BiVO 4 [46], sulfide-based materials [22], CoO [47] and cadmium chalcogenides [48] have to be noted.…”