A novel, facile, and efficient two-step hydrothermal route for WS2 nanosheets and its optimistic exposure as competent industrial-level sonocatalyst

Abstract

The present work reports a fast and efficient two-step hydrothermal route that can deliver both WO3 nanoparticles and WS2 nanosheets. Prepared samples were characterized using X-ray diffraction, Raman analysis, Fourier transform infrared spectroscopy, and UV–Vis–NIR absorption. Scanning electron microscopy analysis reveals that WS2 powder is composed of nanosheets having layered structures. WO3 nanoparticles and WS2 nanosheets synthesized were found to be efficient sonocatalyst and exhibited good removal efficiency (RE) in the case of water containing methylene blue (MB), which is the most commonly used dye in textile and wood industries. Under same catalyst dosage (1 g/L) and MB concentration (10 mg/L), WO3 nanoparticles showed 61.2% of RE within 90 min, whereas WS2 nanosheets showed a remarkable RE of 85.4% within 30 min. Brunauer–Emmett–Teller surface area analysis and some quantitative explanations are furnished for better sonocatalytic performance of WS2 nanosheets compared to WO3 nanoparticles. It was also established that sonolysis and adsorption, performing separately, do not have significant role in dye degradation. Reusability of WS2 nanosheets is also checked for five consecutive runs and they showed excellent cavitation erosion resistance and hence reproducibility that are very important to be established as a method for industrial dye-contaminated wastewater treatment. Finally yet importantly, capability of suggested sonocatalytic process for industrial-level wastewater treatment was illustrated by calculating electric energy in kilowatt hours (kWh) required to degrade 1 kg of MB (8.3 × 103 kWh/Kg). The lower value energy consumption profile for present sonocatalytic process offers incredible future prospects.