Controllable synthesis of graphitic C₃N₄/ultrathin MoS₂ nanosheet hybrid nanostructures with enhanced photocatalytic performance

Abstract

Graphitic C₃N₄/ultrathin MoS₂ (MoS₂/g-C₃N₄) hybrids were synthesized via a facile bathing and ultrasound method. In this process, a well-bonded interface structure was formed between ultrathin MoS₂ nanosheets and g-C₃N₄ through adjusting the amount of MoS₂ in the MoS₂/g-C₃N₄ hybrids. The MoS₂/g-C₃N₄ hybrids were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (Raman), transmission electron microscopy (TEM) and UV-vis spectroscopy (UV-vis). The MoS₂/g-C₃N₄ photocatalyst showed excellent photocatalytic activity in the photodegradation of organic pollutants. In this work, methyl orange (MO) was used as the simulative pollutant; the highest photodegradation rate (92.4%) was obtained when the amount of MoS₂ was 5 wt% in the MoS₂/g-C₃N₄ hybrids (0.05-MC), with a kinetic constant of 0.0189 min^-1 after being irradiated under visible light for 2 h. Besides, 0.05-MC also showed excellent recyclability and chemical stability, and a photodegradation rate of 79.93% was reached after being reused 10 times. For practical pollutants, the photocatalytic degradation rates of ciprofloxacin (CIP) and tetracycline hydrochloride (TC) have been increased dramatically under the visible light irradiation. The excellent photocatalytic properties of MoS₂/g-C₃N₄ hybrids can be ascribed to the enhanced separation rate and accelerated mobility of photogenerated charges through ultrathin MoS₂ nanosheets' modification.