Ambient Aqueous Growth of Cu 2 Te Nanostructures with Excellent Electrocatalytic Activity toward Sulfide Redox Shuttles

A new aqueous and scalable strategy to synthesize surfactant‐free Cu 2 Te nanotubes and nanosheets at room temperature has been developed. In aqueous solution, Cu 2 E (E = O, S, Se) nanoparticles can be easily transformed into Cu 2 Te nanosheets and nanotubes via a simple anion exchange reaction under ambient conditions. The formation of Cu 2 Te nanosheets is ascribed to a novel exchange‐peeling growth mechanism instead of simple Kirkendall effect; and the resultant nanosheets can be further rolled into nanotubes with assistance of stirring. The morphologies of Cu 2 Te nanosheets and nanotubes can be easily controlled by changing the synthesis parameters, such as the concentration of precursors, the size of nanoparticle precursor, and the amount of NaBH 4 , as well as the stirring speed. Thus‐formed Cu 2 Te nanostructures exhibit excellent catalytic activity toward sulfide redox shuttles and are exploited as counter electrodes catalysts for quantum dot sensitized solar cells. The performance of Cu 2 Te nanostructures strongly depends on their morphology, and the solar cells made with counter electrodes from Cu 2 Te nanosheets show the maximum power conversion efficiency of 5.35%.