CdS/Cu2S co-sensitized TiO2 branched nanorod arrays of enhanced photoelectrochemical properties by forming nanoscale heterostructure

This paper described a facile method for the design and utilization of three-dimensional TiO 2 branched nanorod arrays with CdS and Cu 2 S quantum dots co-sensitized photoelectrode for photoelectrochemical water splitting . CdS and Cu 2 S quantum dots were attached on the surface of TiO 2 BNRs by successive ionic layer adsorption and reaction (SILAR). The morphology and element composition of the fabricated samples were characterized by field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and the optical features were measured by UV–vis diffuse reflection spectroscopy (UV–vis DRS) and photocurrent density–voltage (I–V) curves. The photocurrent value can be significantly enhanced due to the introduction of CdS and Cu 2 S quantum dots on the TiO 2 BNRs surface. The 9 cycles of CdS and 6 cycles of Cu 2 S presented the best performance and reached a high photocurrent density to 13.65 mA at 0 V versus Ag/AgCl and hydrogen generation efficiency of 7.74% at −0.467 V versus Ag/AgCl. This enhancement can be attributed to the improved light absorption and the heterojunction formed between CdS and Cu 2 S, which can greatly promote the introduction and transportation of the photo electrons. This work provided a facile way for the synthesis of high performance photoelectrode for photoelectrochemical water splitting.