Surface-modified, dye-sensitized niobate nanosheets enabling an efficient solar-driven Z-scheme for overall water splitting.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35947708.
- Also identified by DOI 10.1126/sciadv.adc9115 and PMC identifier 9365272.
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Abstract
While dye-sensitized metal oxides are good candidates as H<sub>2</sub> evolution photocatalysts for solar-driven Z-scheme water splitting, their solar-to-hydrogen (STH) energy conversion efficiencies remain low because of uncontrolled charge recombination reactions. Here, we show that modification of Ru dye-sensitized, Pt-intercalated HCa<sub>2</sub>Nb<sub>3</sub>O<sub>10</sub> nanosheets (<b>Ru</b>/Pt/HCa<sub>2</sub>Nb<sub>3</sub>O<sub>10</sub>) with both amorphous Al<sub>2</sub>O<sub>3</sub> and poly(styrenesulfonate) (PSS) improves the STH efficiency of Z-scheme overall water splitting by a factor of ~100, when the nanosheets are used in combination with a WO<sub>3</sub>-based O<sub>2</sub> evolution photocatalyst and an I<sub>3</sub><sup>-</sup>/I<sup>-</sup> redox mediator, relative to an analogous system that uses unmodified <b>Ru</b>/Pt/HCa<sub>2</sub>Nb<sub>3</sub>O<sub>10</sub>. By using the optimized photocatalyst, PSS/<b>Ru</b>/Al<sub>2</sub>O<sub>3</sub>/Pt/HCa<sub>2</sub>Nb<sub>3</sub>O<sub>10</sub>, a maximum STH of 0.12% and an apparent quantum yield of 4.1% at 420 nm were obtained, by far the highest among dye-sensitized water splitting systems and comparable to conventional semiconductor-based suspended particulate photocatalyst systems.