One-Pot Hydrothermal Synthesis of La-Doped ZnIn(2)S(4) Microspheres with Improved Visible-Light Photocatalytic Performance

Impurity element doping is extensively taken as one of the most efficient strategies to regulate the electronic structure as well as the rate of photogenerated charge separation of photocatalysts. Herein, a one-pot hydrothermal synthesis process was exploited to obtain La-doped ZnIn(2)S(4) microspheres, aiming at gaining insight into the role that doping ions played in the improvement of pollutant photodegradation. Systematical characterization means, comprising of X–ray photoelectron spectroscopy (XPS), ultraviolet–visible (UV–vis) diffuse reflection spectroscopy and Raman spectra, combination with high-resolution transmission electron microscopy (HRTEM), were employed to in depth reveal the concomitancy of La ions and ZnIn(2)S(4) crystal lattice. The results showed that the La-doped ZnIn(2)S(4) samples exhibited a slightly wider and stronger spectral absorption than pristine ZnIn(2)S(4); and the specific surface area of doped ZnIn(2)S(4) samples was a bit larger. The La-doped ZnIn(2)S(4) electrodes showed improved photocurrent response, and the photocurrent density reached a maximum value at La content of 1.5 wt%. As expected, La-doped ZnIn(2)S(4) samples exhibited a remarkable enhancement of photocatalytic behaviour toward the photodegradation of tetracycline hydrochloride (TCH) and methyl orange (MO). The prominently enhanced photoactivity of doped ZnIn(2)S(4) samples was due to the synergistic effect of the elevated visible-light absorption ability and effective photogenerated charge carriers’ separation.