Search

MoS2/rGO composites were synthesized by hydrothermal method from the precursors of MoS2 and reduced graphene oxide (rGO) prepared in the former steps. The influence of the synthesis conditions including hydrothermal temperature and mass ratio of MoS2 to rGO on the structure, morphology, and optical absorption capacity of the MoS2/rGO composites was systematically investigated using physicochemical characterizations. The photocatalytic performance of as-prepared samples was investigated on the degradation of Rhodamine B under visible light, in which, the composites obtained at hydrothermal temperature of 180°C and MoS2/rGO mass ratio of 4/1 exhibited the highest photodegradation efficiency of approx. 80% after 4 hours of reaction. This enhancement in photocatalytic behaviour of composites could be assigned to the positive effect of rGO in life time expansion of photoinduced electrons—holes. [ABSTRACT FROM AUTHOR]

g-C3N4/BaTiO3 composite was hydrothermally synthesized at 200°C for 24 h from a dispersed mixture of g-C3N4 and BaTiO3 in water, in which BaTiO3 was hydrothermally synthesized at 200°C for 48 h using barium nitrate, isopropanol, titanium tetrachloride and sodium hydroxide as precursors without assistance of any surfactant; and graphitic carbon nitride (g-C3N4) was prepared by pyrolysis of melamine at 520°C. The obtained materials were characterized by X-ray diffraction, infrared spectra, scanning electron microscopy, elemental mapping, X-ray photoelectron spectroscopy and ultraviolet–visible diffuse reflectance spectroscopy. The photocatalytic activity of the materials was assessed by degradation of methylene blue (MB) under visible light. The enhancement of photocatalytic activity of the g-C3N4/BaTiO3 composite compared to the single components, g-C3N4 and BaTiO3 was observed, which is attributed to the reduction of combination rate of photogenerated electron–hole pairs in the composite. The MB degradation over the composite was mainly attributed to the photoreduction process induced by the superoxide radical anions (•O2−) and hydroxyl radicals (•OH); and a mechanism was also proposed based on the heterojunction model from the two semiconductor components. [ABSTRACT FROM AUTHOR]

The n%Mn-MoS2/rGO (labeled as n%MMS/rGO, where n% = Mn/(Mn + Mo) in mol) composites were successfully prepared by a facile hydrothermal method from the Mn-MoS2 (MMS) and rGO precursors, in which the MMS was obtained by a facile one-step calcination of (NH4)6Mo7O24·4H2O, (NH2)2CS, and Mn(CH3COO)2·4H2O as precursors in N2 gas at 650°C. The samples were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron paramagnetic resonance spectroscopy (EPR), UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), and X-ray photoelectron spectroscopy (XPS), which indicates the composites containing nanosheets of Mn-MoS2 and rGO components. The photocatalytic activities of the n%MMS/rGO composite photocatalysts were evaluated through the photodegradation of rhodamine B (RhB) under the visible light irradiation. The enhancement in the photocatalytic performance of the achieved composites was attributed to the synergic effect of Mn doping and rGO matrix. The investigation of photocatalytic mechanism was also conducted. [ABSTRACT FROM AUTHOR]

Visible‐light‐driven photocatalysis has received considerable attention in the environmental treatment in recent years. In this paper, WS2/g‐C3N4 composite photocatalysts with various contents of WS2 and g‐C3N4 were synthesized by a facile method via heating the mixtures of tungstic acid and thiourea, and denoted as nWCN, where n is weight ratio of thiourea to tungstic acid. The composites were characterized by XRD, SEM, EDS, TEM, IR, Raman spectroscopy, XPS, TGA, and UV–vis DRS. The characterizations reveal that the composites contain WS2 nanosheets coated by g‐C3N4 and the relative content of WS2 in the composites decreases with increasing amount of thiourea in the reaction mixtures. All the composites exhibited the better photocatalytic activity in degradation of methylene blue in aqueous solution than the single components, WS2, and g‐C3N4. Among them, 7WCN sample performed the highest activity. A synergistic effect between WS2 and g‐C3N4 in photocatalytic activity for the composites was observed. [ABSTRACT FROM AUTHOR]