Nb–TiO2 nanomaterials with hierarchical porosity (macro, meso and micropores) have been successfully synthesized using a simple self-assembly method without the need for a surfactant. Improved textural and structural properties were obtained after incorporation of Nb within a TiO2 framework. High Nb dispersion and Nb–Ti interaction were achieved at the Nb–TiO2 nanomaterial surface. With Nb addition to TiO2, the balance of Lewis to Brønsted acid sites was maintained however the acidity increased in strength. The catalytic transformation of 2-propanol and n-butanol was favoured at very low temperatures with a change in selectivity; the dehydration reaction of alcohols into alkenes was promoted by the increase in acidity of the Nb–TiO2 nanomaterials.