Urchin-like TiO2 structures decorated with lanthanide-doped Bi2S3 quantum dots to boost hydrogen photogeneration performance.

• XPS and theoretical studies confirmed the doping of the Bi 2 S 3 QDs by Yb and Er ions. • TiO 2 decorated by 10 wt.% of Yb-Bi 2 S 3 QDS allows to produce 1576.7 μmol H 2 /g cat. • Stability of Yb-Bi 2 S 3 QDs/TiO 2 composite in Na 2 S/Na 2 SO 3 electrolyte was proven. The formation of heterojunctions between wide- and narrow-bandgap photocatalysts is commonly employed to boost the efficiency of photocatalytic hydrogen generation. Herein, the photoactivity of urchin-like rutile particles is increased by decorating with pristine as well as Er- or Yb-doped Bi 2 S 3 quantum dots (QDs) at varied QD loadings (1–20 wt%) and doping degrees (1–15 mol%), and the best hydrogen evolution performance is achieved at Er and Yb contents of 10 mol%. Specifically, a hydrogen productivity of 1576.7 μmol g cat −1 is achieved after 20-h irradiation for TiO 2 decorated by 10 mol% Yb-doped Bi 2 S 3 QDs. Theoretical calculations show that the introduction of defects into the Bi 2 S 3 lattice through Er/Yb doping promotes the creation of new energy levels and facilitates the transport of photogenerated charges during photocatalysis. [ABSTRACT FROM AUTHOR]