Z-scheme group-11-chalcogenides heterostructures for solar-driven photocatalytic water splitting.

Z-scheme photocatalysts for solar-driven overall water splitting have attracted tremendous attention due to their strong redox abilities and enhanced solar-light absorptions. This study focuses on the theoretical design of XAu 2 Y (X, Y S, Se, Te) heterostructures for solar-driven photocatalytic water splitting based on first-principles calculations. The band edges and internal electric fields indicate that SAu 2 S/TeAu 2 Te, SeAu 2 Se/TeAu 2 Te, TeAu 2 Te/SAu 2 Se and TeAu 2 Te/SeAu 2 S are highly efficient Z-scheme photocatalysts for solar-driven overall water splitting, with enhanced optical absorbances by 1.5–2 times and high solar-to-hydrogen energy conversion efficiencies of 20.47%, 19.94%, 16.50% and 22.81%. Furthermore, taking TeAu 2 Te/SeAu 2 S as an example, HER (Δ G H * = 0.16 e V) and OER (U = 2.25 V) reactions show excellent photocatalytic performances. These results extend the scope of solar-driven overall-water-splitting photocatalysts to group-11 chalcogenides heterostructures, which is expected to inspire the experimental fabrications and relative investigations. Z-scheme heterostructures based on XAu 2 Y (X, Y S, Se, Te) are theoretically screened for solar-driven overall water splitting, which exhibit enhanced optical absorbances, high solar-to-hydrogen energy conversion efficiencies and excellent redox reactions. [Display omitted] • The Z-scheme heterostructures are designed to effectively separate photogenerated carriers. • Constructing heterostructures promote the excellent optical absorbances. • The Z-scheme heterostructures possess high solar-to-hydrogen energy conversion efficiencies. • High catalytic activities for HER and OER are confirmed by the Gibbs free energies. [ABSTRACT FROM AUTHOR]