Thioacetamide-induced CeOS nanostructures with tunable morphology for supercapacitors in wide pH range.

Here, Rare-earth metal oxysulfide CeOS nanostructures with tunable morphology are successfully grown on carbon cloth (CC) for supercapacitors (SCs) via a facile hydrothermal process followed by pyrolysis treatment for the first time. The feeding amount of sulfur source thioacetamide (TAA) plays an important role in the formation of CeOS nanostructures with tunable morphology. Adjusting TAA feeding amount from 0.5 to 1.0, 1.5, and 2.0 g, the morphology of the resulted CeOS nanostructure can change from pine bark-like agglomerated nanoparticles to fan-shaped nanosheets with edged branches, cuttlefish-like nanostructure with long terminal whiskers and polygon prism with spikes. Among them, CeOS/CC-1.0 g TAA nanostructure with largest specific surface area and abundant mesopores exhibits a high specific capacitance of 670, 321.5 or 588.3 mF cm at 1 mA cm in an acid, neutral or alkaline electrolyte, respectively. Moreover, CeOS/CC-1.0 g TAA electrode delivers excellent cycling stability with high capacitance retention of 93% after 5000 cycles in alkaline electrolyte. Our findings present a new strategy to fabricate rare-earth metal oxysulfide CeOS nanostructures with controllable morphology and systematically reveal their electrochemical performance for SCs, moreover, provide new perspectives for boosting the preparation and application of metal oxysulfides in energy storage.