biostudies-literatureUnknown147(38)Wilson AAPhotocatalytic water splitting offers a scalable and potentially low-cost route for the production of renewable hydrogen. Recently, a state-of-the-art system based on flux-mediated Al³⁺-doped SrTiO₃, modified with Rh-Cr-based proton reduction and CoOOH water oxidation cocatalysts, achieved apparent quantum yields for unassisted water splitting of up to 93%. Herein, we focus on the role of Al³⁺ doping and Rh-Cr-based cocatalyst deposition on the accumulation and reaction dynamics of the long-lived holes required to drive water oxidation. We employ in situ and operando photoinduced absorption spectroscopy (PIAS) under water splitting conditions complemented by X-ray photoelectron spectroscopy (XPS). XPS data indicate that Al³⁺ doping suppresses surJournal of the American Chemical Society34438-34448https://www.ebi.ac.uk/biostudies/studies/S-EPMC12464978biostudies-literatureLong-Lived Hole Accumulation in Al:SrTiO<sub>3</sub>/Rh-Cr Photocatalyst Systems under Continuous Irradiation and Its Correlation with Overall Water Splitting Efficiency.PMC12464978Wilson AALee TLMoss BRegoutz AHisatomi TThakur PKTakata TDomen KRiaz AADurrant JRKalha CfalseLong-Lived Hole Accumulation in Al:SrTiO<sub>3</sub>/Rh-Cr Photocatalyst Systems under Continuous Irradiation and Its Correlation with Overall Water Splitting Efficiency.Photocatalytic water splitting offers a scalable and potentially low-cost route for the production of renewable hydrogen. Recently, a state-of-the-art system based on flux-mediated Al³⁺-doped SrTiO₃, modified with Rh-Cr-based proton reduction and CoOOH water oxidation cocatalysts, achieved apparent quantum yields for unassisted water splitting of up to 93%. Herein, we focus on the role of Al³⁺ doping and Rh-Cr-based cocatalyst deposition on the accumulation and reaction dynamics of the long-lived holes required to drive water oxidation. We employ in situ and operando photoinduced absorption spectroscopy (PIAS) under water splitting conditions complemented by X-ray photoelectron spectroscopy (XPS). XPS data indicate that Al³⁺ doping suppresses sur2025-01-01T00:00:00Z2025 Sep2026-06-03T21:23:19.258Z2026-05-01T03:11:04.299ZS-EPMC124649784093486410.1021/jacs.5c07521