Facile synthesis of Cu2O nanocages and gas sensing performance towards gasoline

Abstract

Facile synthesis of uniform cubic cuprous oxide (Cu₂O) nanocages has been realized via an acidic etching method without any surfactant at 35 °C. The edge length of the Cu₂O nanocages was 80–90 nm, and the thickness of the walls was about 5 nm. Moreover, the wall thickness of these nanocages could be adjusted by changing the reaction temperature. The formation mechanism of the Cu₂O nanocages was investigated. Ascorbic acid played an important role in this experiment. Owing to its reducing action, Cu(OH)₂ was first reduced to solid Cu₂O nanocubes in an aqueous solution. Almost immediately these nanocubes were etched into hollow ones through the acidic etching effect. Eventually, Cu₂O nanocages which had thinner walls and more complete structures than those previously mentioned were produced in the presence of hydrazine hydrate (N₂H₄·H₂O). The as-prepared Cu₂O nanocages have superior gas sensing performance toward gasoline comparing with the solid Cu₂O nanocubes.