Photoelectrochemical Performance of Composition Tuned BiOCl Nanosheet Arrays

BiOCl nanosheet arrays were successfully synthesized by successive ionic layer adsorption and reaction method onto transparent conducting electrode (TCO). The composition and band structure have been controlled by vacuum assisted annealing. The as-prepared materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, UV-Vis spectroscopy, Cyclic Voltammetry (CV) and Electrochemical Impedance spectroscopy (EIS). Our result indicate that 30 cycle deposited BiOCl nanosheet arrays have effectively covered surface of TCO electrode. Their composition and band structures were gradually changed from BiOCl to Bi₁₂O₁₅Cl₆ with band gap range 3.5 eV to 2.7 eV by increasing annealing temperature. We investigated their phoelectrochemical performance and the photoelectrodes have an optimum photocurrent density of 100 μA/cm² when annealed at 500 ^oC. The excellent photoelectrochemical properties of our photoelectrodes suggest that the BiOCl nanosheet arrays have potential applications in Solar energy harvesting.