A novel alpha-Fe2O3@MoS(2)QDs heterostructure for enhanced visible-light photocatalytic performance using ultrasonication approach

摘要

Constructing excellent heterojunction to improve the photocatalytic performance of materials is critically important. Herein, we report an effective simple, easy preparation method for alpha-Fe2O3@MoS2 QDs nanocomposite via two two-step process, including hydrothermal and ultrasonication approaches. The as-prepared materials were characterized using X-ray diffraction (XRD), Transmission electron microscope (TEM), TGA, X-ray fluorescence (XRF) and photoluminescence spectra (PL). The refined PXRD patterns of alpha-Fe2O3 photocatalyst confirm the formation of a single trigonal phase of Fe2O3 without another phase impurities. When the MoS(2)QDs were coupled with alpha-Fe2O3, the phase was changed to a single monoclinic phase with C 2/C space group and no peaks observed for MoS2 QDs. Morphological analyses reveal the successful formation of Fe2O3@MoS2 QDs nano-composites with uniform distribution of MoS(2)QDs on the Fe2O3 surface. The XRF analysis confirmed the presence of Mo, S, and Fe elements indicating the nanocomposite formation. The Uv-vis results revealed the enhancement of absorption capability of the alpha-Fe2O3@MoS2 QDs material, particularly in the white light region. Very noticeably, the as-prepared alpha-Fe2O3@MoS2 QDs exhibit high photocatalytic activity performance (84%) toward methylene blue (MB) in 1 min under visible light irradiation. The superior photocatalytic performance of the prepared material can be attributed to the enhancement of the light absorption and the high separation efficiency of photogenerated electron-hole pair in Fe2O3@MoS2 QDs structure, which confirmed by PL analysis. The mechanism of photocatalytic degradation of MB over Fe2O3@MoS2 QDs nanocomposite was suggested. This work provides a new, low-cost and straightforward idea for enhancement of the degradation performance of organic pollutants in water.