Surface self-assembly of functional molecules or nanoscale building blocks is an effective strategy for the syntheses of advanced materials. Natural cellulose-rich substances have unique macro-to-nano hierarchical structural features. The fabrication of nanoarchitectures, employing specific guest species on the surfaces of the fine structures of such substances, results in corresponding artificial nanomaterials that possess the chemical functionalities and physical properties of both sides. Metal oxide thin film coatings with nanometer precision on the nanofibers of bulk cellulose-rich substances not only yield replicas of nanostructured materials, but also make it possible for further assemblies of functional units on the surfaces. Hence, nanostructured metal oxides and further composites, as well as surface-functionalized cellulose-based composites are fabricated by employing cellulose-rich substances as templates or scaffolds. The three-dimensional cross-linked porous structures, with the high surface area of the resultant nanomaterials or composites, lead to superior performance when employed as photocatalysts, electrode materials, and sensing matrices, on which this report is focused.