3D Bi2S3 salix leaf-like nanosheet/TiO2 nanorod branched heterostructure arrays for improving photoelectrochemical properties

Abstract

We firstly fabricated a peculiar 3D structure of Bi₂S₃ salix leaf-like nanosheet/TiO₂ nanorod branched heterostructure arrays by a convenient hydrothermal method and discussed their mechanism of improving photoelectrochemical cell (PEC) properties. The salix leaf-like Bi₂S₃ nanosheets (NSs) were grown on TiO₂ nanorod arrays through controlling the molar ratio of EDTA-Na₂/Bi³⁺ and the reaction time. The morphology, crystal structure, microstructure and optical performance of the 3D Bi₂S₃ NS/TiO₂ NRs at different reaction times were investigated. The results show that the branched heterostructure of 3D Bi₂S₃ NS/TiO₂ NR arrays exhibits enhanced photocurrent density and optical absorption, which were attributed to the larger Bi₂S₃ surface area, as well as a direct electron path within the salix leaf-like Bi₂S₃ NS and TiO₂ NR heterojunctions, resulting from more excitation sites of incident light. The photocurrent density of the 3D Bi₂S₃ NS/TiO₂ NR arrays was almost 9 times greater than that of pristine TiO₂ without a branching structure. The results of the present work demonstrate that fabrication of the branched Bi₂S₃ NS/TiO₂ NR heterogeneous structure is a significant fabrication technology with great promise in PECs.