Transformation of multilayer WS2 nanosheets to 1D luminescent WS2 nanostructures by one-pot supercritical fluid processing for hydrogen evolution reaction

Abstract

Here, we report the transformation of the manifold layers of bulk WS2 into one-dimensional (1D) WS2 nanostructures using one-pot and energy efficient supercritical fluid (SCF) processing with a short reaction time of 30 min at 400 °C. The exfoliation of few layer WS2 nanosheets followed by self-scrolling into 1D WS2 nanostructures under the SCF processing was confirmed by XRD, Raman, UV–Visible, FE-SEM, HR-TEM, and AFM analysis. Moreover, the as-synthesized 1D WS2 nanostructures emitted a strong blue colour and exhibited the excitation-dependent photoluminescence behaviour owing to the formation of polydisperse size distribution of the WS2 nanostructures. Remarkably, a substantial electrochemical hydrogen evolution reaction has been found in the as-synthesized 1D WS2 nanostructures with the onset potential of ~230 mV vs RHE and a Tafel slope of 112 mV/dec. Consequently, the prepared 1D WS2 nanostructures can be considered to be a promising candidate for photoluminescence and electrochemical hydrogen evolution.