Solvothermal synthesis and characterization of monoclinic WO 3 nanoplatelets. Investigation of their photocatalytic performance

Abstract

An original, facile way based on a non-aqueous sol–gel solvothermal process has been developed to synthesize 2D tungsten trioxide (WO3) nanoplatelets in one pot. The reaction between Tungstic acid (H2WO4) and 1-hexanol was a simple process, which resulted in the formation of highly crystalline metal oxide based on WO3 with an average size ranging between 30 and 50 nm, and with a correspondingly high surface area. The structural, morphological, functional group, optical qualities of the materials and the properties of the adsorption surfaces were all examined, and the degree of surface hydroxyls (– OH groups) has been examined. The products of the reaction were characterized by X-ray Powder Diffraction, Scanning Electron Microscopy, Transmission Electron Microscopy, Nitrogen adsorption, and pore-size distribution Brunauer-Emmett-Teller, Fourier Transform Infrared Spectroscopy and Nuclear Magnetic Resonance Spectroscopy techniques. which indicated the formation of di-hexyl ether as a result of the solvothermal reaction. The optical absorption, measured using UV–Vis Diffuse Reflectance Spectroscopy, revealed a narrow bandgap (Eg = 2.18 and 2.48 eV for WO3-24 and WO3-48, respectively) compared to that of for bulk WO3 (2.7 eV), attributable to oxygen vacancies. Upon increasing dwell time from 24 to 48 h, a blue-shift was observed, highlighting a quantum size effect. The as-prepared WO3 nanoplatelets displayed excellent photocatalytic performance for degrading Rhodamine B under visible light-emitting diode light with up 99 % degradation rate was achieved in 120 min. Thus, the enhanced Rhodamine B photodegradation in the presence WO3-24 along with H2O2 was assigned to the reactive oxygen species (ROS) such as ; OH and RhB *+ , involving in the strong synergistic effect between WO3 and H2O2, effectively separating of photocarriers and, as a consequence, boosting the photocatalytic efficiency.

Degradation of Methylparaben Using Optimal WO3 Nanostructures: Influence of the Annealing Conditions and Complexing Agent

“…Figure S1 (see Supplementary Material) shows the XRD pattern of WO 3 nanostructures, where all peaks (002), (020), (200), (112), (022), (220), and (221) can be associated to the monoclinic WO 3 phase. For both electrolytes, the sharper peaks were (002), (020) and (220), indicating that both synthesized nanostructures belong to the monoclinic phase of WO 3 [ 21 , 54 , 55 , 56 , 57 , 58 ].…”