Cobalt hydroxide colloidal particles precipitation on nanoclay layers for the formation of novel nanocomposites of carbon nanotubes/nanoclay

摘要

Here we demonstrated the formation of Co(OH) 2 colloidal particles on the surface of nanoclay layers with pH-controlled ion precipitation. The brucite-like phase of Co(OH) 2 colloidal particles obtained exhibited a tendency for irregular growth with increasing pH. The precipitation of Co(OH) 2 colloidal particles on the nanoclay surface led to the formation of a weakly ordered layered structure in the nanoclay as evidenced by the change of (0 0 1) reflections in the nanoclay structure. Two processes, physical adsorption and chemical adsorption, should be involved in the precipitation of Co(OH) 2 particles on the nanoclay surface. The catalysis of the produced Co(OH) 2-nanoclay hybrid was proved by the growth of CNTs with chemical vapor deposition. Under the pH value of 9.5, the resulting CNTs created a network-like structure connecting the nanoclay flakes while the nanoclay structure displayed signs of degradation after the growth of CNTs within its interlayer space. The novel CNTs-nanoclay composite structure holds high potentials for application as advanced polymer reinforcements.