Multiple carrier-transfer pathways in a flower-like In2S3/CdIn2S4/In2O3 ternary heterostructure for enhanced photocatalytic hydrogen production

Abstract

A novel flower-like In₂S₃/CdIn₂S₄/In₂O₃ (ICS) ternary heterostructure (HS) is rationally constructed for the first time by a series of carefully designed procedures. In₂O₃ nanoflakes are the main constituent units which assemble into a flower-like skeleton structure, and CdIn₂S₄ nanoparticles are in situ generated on the surface of In₂O₃ nanoflakes through the transformation of CdS quantum dots (QDs) while In₂S₃ nanoparticles are in situ produced at the region between CdIn₂S₄ nanoparticles and In₂O₃ nanoflakes resulting from a synchronous sulfuration procedure. As expected, the rationally designed ICS ternary HSs display significantly enhanced photocatalytic H₂ production, especially ICS₅ (sulfurized for 5 h) with the highest H₂ evolution rate of 20.04 μmol h⁻¹ (10 mg catalyst is used for photocatalytic reaction), which is 26.7 times and 2.6 times higher than that of pure In₂O₃ (0.75 μmol h⁻¹) and In₂S₃/In₂O₃ binary HS (7.88 μmol h⁻¹), respectively. The enhanced photocatalytic activity can be attributed to the multiple interfaces formed in the ICS HSs, including the CdIn₂S₄–In₂O₃ interface, the In₂S₃–In₂O₃ interface, and the CdIn₂S₄–In₂O₃–In₂S₃ interface, which construct multiple pathways for the transfer of photogenerated charge carriers, effectively promoting the photocatalytic hydrogen production.