In recent years, nanofibrous materials derived from biopolymers have attracted more interest due to their numerous applications. In our study, a simple composite of cellulose nanocrystals, and cobalt oxide nanoparticles was elaborated using sodium borohydride as a chemical reducer. It has been shown that Co3O4 nanoparticles were grown on the surface of cellulose nanocrystals. An important quantity of cobalt oxide nanoparticles was detected using ICP-OES (13.5 g contained in 100 mg of the composite). The si…