Nowadays, the search to develop sustainable materials using materials from renewable sources to multifunctional applications is a great challenge. In this context, the present research evaluated producing new carboxymethyl cellulose hydrogels with nano-graphene oxide incorporated into potential applications in biomedical and energy areas. Spectroscopies analysis (FTIR, Raman, UV Vis), X-ray diffraction, and morphological (SEM, TEM, BET) were used to characterize these hydrogels. In addition, quantum dots based on cobalt sulfide were made to evaluate the energy application. Moreover, biocompatibility was tested using an MTT assay. The results showed that the nGO changes the structure of hydrogels and their crystalline structure, mainly because of heat treatment and the donation of hydroxyl groups by CMC. In addition, the chemical groups of hydrogels suffer red and blue shifts by the nGO presence. Moreover, the nGO was homogeneously spread into the hydrogel matrix. Furthermore, the MTT assay was performed to analyze the cytotoxicity of hydrogels with nGO (over 90%). In addition, the cell solar production using hydrogels and cobalt quantum dots (size of 3 nm) provided a potential application of these materials to renewable energy sources.