Eco-friendly synthesis of nanocrystalline zirconia with tunable pore size

• Nanoporous zirconia materials with controlled pore structures.
• Eco-friendly synthesis method for the materials without addition of acid or base.
• The average pore diameters range from 1.2 to 4.2 nm.

Microporous/mesoporous zirconia materials have been successfully synthesized by controlling hydrolysis rate without adding acid or base and calcining under mild conditions, and characterized by XRD, TEM and N2 adsorption-desorption. The results show that the as-synthesized materials are super-microporous (pore size in the range of 1–2 nm) as using dimethyl distearyl ammonium chloride as the template, but mesoporous (pore size >2 nm) when didodecyl dimethyl ammonium chloride and bisoctyl dimethyl ammonium chloride are employed. By changing the carbon chain length of the templates, the average pore sizes of the zirconia samples are tailored, and a range of pore sizes from 1.2 to 4.2 nm is obtained.