Formation of uniform mesoporous TiO2@C-Ni hollow hybrid composites.

Highly efficient bifunctional metallic nickel nanoparticles (NPs) are highly desired for practical applications in catalysis and adsorption. However, the low surface area and the aggregation often lead to their poor activities during catalysis and adsorption. Here, we have developed a facile strategy to synthesize monodisperse magnetic mesoporous TiO2(mTiO2)@C-Ni hollow spheres using carboxyl-functionalized polystyrene (CPS) spheres as sacrificial templates, which exhibit excellent performance during both catalysis of 4-nitrophenol (4-NP) and good affinity towards His-rich proteins. The enhanced activity of hybrid mTiO2@C-Ni composites could be related to their hollow structure, large surface area, high density of nickel NPs, and the monodisperse morphology. The results reported here may open a new avenue for the construction of advanced nanostructures for promising applications in catalysis, adsorption, energy storage, etc.