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%.