In:
Journal of Materials Chemistry A, Royal Society of Chemistry (RSC), Vol. 10, No. 45 ( 2022), p. 24247-24257
Kurzfassung:
Oxysulfide photocatalyst Y 2 Ti 2 O 5 S 2 is a narrow bandgap semiconductor that achieves overall water splitting via one-step photoexcitation under a wide range of solar spectrum ( 〈 640 nm). However, the photophysical properties that enable the visible-light-driven overall water splitting in Y 2 Ti 2 O 5 S 2 are not fully understood. Here, temperature/power-dependent and time-resolved photoluminescence spectroscopies reveal the transition of luminescence mechanism from exciton and free carrier recombination at low temperature to band-tail recombination at room temperature. Importantly, the band-tail states help to sustain a long carrier lifetime in Y 2 Ti 2 O 5 S 2 , which is beneficial to achieving overall water splitting. Meanwhile, a high density of band-tail states may negatively affect photocatalytic activity due to the trap of photocarriers. Density function theory calculations reveal possible origins of the band-tail states, i.e. , spatial potential fluctuations resulting from the random distribution of O S and S O antisites. Our findings reveal a new carrier management mechanism for photocatalysis that could guide the design of more efficient Y 2 Ti 2 O 5 S 2 photocatalyst.
Materialart:
Online-Ressource
ISSN:
2050-7488
,
2050-7496
Sprache:
Englisch
Verlag:
Royal Society of Chemistry (RSC)
Publikationsdatum:
2022
ZDB Id:
2702232-8
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