MoO3-templated synthesis of TiO2@C-Ni microtubes for efficient catalysis and protein adsorption

The hybrid structure of metallic Ni nanoparticles (NPs)-decorated micro/nanotubes has the merits of both unique property of Ni NPs and tubular structure of micro/nanotubes, which is highly desired for many applications. In this study, Ni NPs decorated porous TiO2 microtubes with N-doped carbon layer from polydopamine (PDA) are directly synthesized by an extend stöber method, mussel chemistry and subsequent annealing treatment for the first time. In the synthetic process, a shell layer of nickel ion-embedded in polydopamine (PDA-Ni2+) was covered on the MoO3@TiO2 microcables by nickel ion mediated dopamine polymerization in ammonia solution, resulting in the formation of amorphous TiO2@PDA-Ni2+ microtubes. Notably, the coating of PDA-Ni2+ layer and the dissolution of the MoO3 cores were easily achieved within one-step reaction, greatly facilitating the synthetic progress. After being annealed in nitrogen atmosphere at different temperature, the TiO2@C-Ni microtubes with anatase, rutile phase of TiO2 can be obtained. Benefiting from the high coverage of Ni NPs, large specific surface area as well as one dimensional tubular structure, the as-prepared TiO2@C-Ni microtubes exhibited excellent performance on adsorption for histidine-rich proteins as well as the reduction of 4-nitrophenol. These results may pave a new avenue on constructing 1D TiO2-based microtubes for potential applications in energy storage, photocatalysis etc.