A theoretical/experimental probe to locate hydrogen(s) while constructing hierarchically structured cellulose–zinc oxide composite

To advance biomass-metal oxide composite synthesis, develop its interfacial chemistry and raise its performance in applications, specifying local structures and their effects are of great importance. Herein, a facile hydrothermal route was utilized to prepare a composite of renewable cellulose and zinc oxide. Microstructures from nanoscale to atomic level were examined with electron microscopy, spectroscopic technique and relativistic density functional theory. ZnO nanoparticles uniformly grow on linear cellulose nanofiber, affording an orderly hierarchical structure in general. Chemical interfacial coupling is computationally borne out. Three types of local structures with different hydrogen locations are energetically favored; notably the hydrogen-transfer one is most possibly occurring in the composite, whose interfacial interaction is dominated by orbital attractions and interfacial strength reaches − 5.06 eV. Electronic structures of the composite rationalized experimental diffuse reflectance spectra. The influence of different hydrogen positions in composite on various properties was discussed in detail. Graphic abstract Experimental and computational characterizations unravel local structures of a typical cellulose–ZnO composite, which show different hydrogen positions. Hydrogen-transfer isomers are found the most possibly occurring, resembling the photoanode in dye-sensitized solar cells. The interfacial nature and interaction strength as well as electronic structures are determined by hydrogen locations.