Three types of TiO-compound-based nanobelts (Na2Ti3O7, H2Ti3O7, TiO2) are prepared from commercial TiO2 powders via an alkaline hydrothermal process. Nanostructured sheets based on the as-synthesized nanobelts are prepared using a paper-making process. The nanobelts are connected with hydrogen bonds or/and bridge oxygen atoms and packed together, forming a paperlike porous network structure, with an average pore size of ∼500 nm. The electrical properties and gas sensing of the nanostructured sheets are demonstrated to display sensitivity down to sub-ppb levels. H2Ti3O7 nanobelts decorated with Ag nanoparticles have also been applied as an antibacterial agent.