Scalable Synthesis of Tungsten Disulfide Nanosheets for Alkali-Acid Electrocatalytic Sulfion Recycling and H2 Generation.

WS2 nanosheets hold great promise for a variety of applications yet faces a grand challenge in terms of large-scale synthesis. We report a reliable, scalable, and high-yield (>93 %) synthetic strategy to fabricate WS2 nanosheets, which exhibit highly desirable electrocatalytic properties toward both the alkaline sulfion (S2- ) oxidation reaction (SOR) and the acidic hydrogen evolution reaction (HER). The findings prompted us to develop a hybrid alkali-acid electrochemical cell with the WS2 nanosheets as bifunctional electrode catalysts of alkaline anodic SOR and acidic cathodic HER. The proof-of-concept device holds promise for self-power or low-electricity electrolytic H2 generation and environmentally friendly recycling of sulfion with enhanced electron utilization efficiency.