Heterogeneous doping of visible-light-responsive Y₂Ti₂O₅S₂ for enhanced hydrogen evolution

Abstract

Y2Ti2O5S2, a stable oxysulfide photocatalyst with a bandgap energy of 1.9 eV, has been studied for the purpose of H2 production via sunlight-driven water splitting. Although this material absorbs a...

Nanostructured Tantalum Nitride for Enhanced Solar Water Splitting

“…In addition, the absorption-decay characteristics follows a power law ( At –α , where A and α are the amplitude and exponent, respectively) in the late time range ( t > 1 ns). Such a power-law decay was previously reported by our group for an n-type-doped Y 2 Ti 2 O 5 S 2 photocatalyst, , which was originated from detrapping of holes from exponential tail states (with characteristic energy E 0 ) of the VB in the sub-microsecond time range. The E 0 can be obtained from the relation E 0 = k B T /α, where k B and T are the Boltzmann constant and temperature, respectively.…”

“…In Figure f, the slower decay of the absorption signal is attributed to the high trap density N t for optimized Ta 3 N 5 NRs ( F r = 50 sccm) as compared to un-optimized Ta 3 N 5 NRs ( F r = 90 sccm). The estimated k r / k t (∼10 –9 cm 3 s –1 ) of Ta 3 N 5 NRs is close to the values for direct band-gap semiconductors like perovskites, oxysulfides, , groups III–V, , etc. Moreover, operating under AM1.5G solar light, the estimated lifetimes of minority holes (τ = 1/ k r n d ) are ∼83 ps and 60 ps for Ta 3 N 5 NRs prepared with F r = 50 sccm and 90 sccm, respectively.…”

Flux‐Assisted Synthesis of Y2Ti2O5S2 for Photocatalytic Hydrogen and Oxygen Evolution Reactions

“…This is 67 % of the sample prepared by CaCl 2 flux, due probably to the presence of defects and impurities [15] . The KI, which was used as the surface modification reagent during the doping of Sc for a SSR sample was also applied as a flux to prepare Flux‐Max/3 under the same conditions, which showed much lower H 2 evolution activity of 16 μmol h −1 [23] . In addition, Flux‐1/96 and Flux‐Max/3 exhibited lower activity when the Rh co‐catalyst was loaded using a photodeposition method, as in our previous work, while SSR‐1/96 exhibited similar HER values regardless of the Rh loading method (Figure S20).…”

The multiple roles of rare earth elements in the field of photocatalysis

“…Therefore, to efficiently develop and utilize rare earth oxide photocatalysts, they also need to be rationally photocatalytically modified. [119][120][121][122][123][124][125] Generally speaking, the modification of rare earth oxide photocatalysts is similar to that of other catalysts, which mainly includes two aspects: broadening the light absorption range of photocatalysts and improving the separation efficiency of photogenerated carriers. Among them, broadening the light absorption range of photocatalysts is mainly realized by metal ion doping.…”