Freestanding mesoporous quasi-single-crystalline CO3O4 nanowire arrays.

We report a facile template-free method for the large-area growth of freestanding hollow Co3O4 nanowire arrays on a variety of substrates including transparent conducting glass, Si wafer, and copper foil, et al. These nanowires have the interesting combined properties of mesoporosity and quasi-single-crystallinity. With their high surface area and crystallinity, and their direct growth on conductive substrate, these Co3O4 nanowire arrays will have promising applications in lithium-ion batteries, chemical sensing, and field-emission and electrochromic devices. Using the prepared nanowire arrays as electrode, an electrochemical sensor for hydrogen peroxide sensing has been demonstrated.