Epitaxial grown [hk1] oriented 2D/1D Bi2O2S/Sb2S3 heterostructure with significantly enhanced photoelectrochemical performance.

[Display omitted] • Bi 2 O 2 S 2D nanosheets films were prepared in-situ by one-step hydrothermal method. • [hk1] oriented Sb 2 S 3 NRs were epitaxially grown on Bi 2 S 3 transformed from Bi 2 O 2 S. • 2D/1D Bi 2 O 2 S/Sb 2 S 3 heterojunction constructed a rapid electron migration channel. • The TiO 2 /Bi 2 O 2 S/Sb 2 S 3 -annealed photoelectrode showed 4.37 mA/cm2 at 1.23 V RHE. Bismuth oxysulfide (Bi 2 O 2 S) is a layered material with high carrier mobility, excellent light absorption characteristic and good stability. However, there are few reports about the use of Bi 2 O 2 S in photoelectrochemical (PEC) water splitting. In this paper, Bi 2 O 2 S nanosheets (NSs) films were prepared on FTO substrates by one-step hydrothermal method, which broke the traditional powder state of Bi 2 O 2 S prepared. Based on the high lattice matching between antimony sulfide (Sb 2 S 3) and bismuth sulfide (Bi 2 S 3) obtained from the topological transformation of partial Bi 2 O 2 S, Sb 2 S 3 nanorods (NRs) with [hk1] predominant orientation were epitaxially grown on the surface of Bi 2 O 2 S to establish a transport channel for rapid carrier migration. Titanium dioxide (TiO 2) electron transport layer with oxygen vacancies was introduced into the back to capture and release electrons, further reducing the recombination rate. The photocurrent density of TiO 2 /Bi 2 O 2 S/Sb 2 S 3 -annealed photoelectrode at 1.23 V vs. RHE was 4.37 mA/cm2, which was 13.7 times that of monomer Bi 2 O 2 S. In addition, the TiO 2 /Bi 2 O 2 S/Sb 2 S 3 -annealed photoelectrode had lower charge transfer resistance and the IPCE value up to 48.22%. This study is of great significance for the application of Bi 2 O 2 S based photoelectrodes in the field of PEC water splitting. [ABSTRACT FROM AUTHOR]