Effective biomass utilization for the generation of functional molecules used for green materials is paramount for the realization of a sustainable society. In the present review, phenolic compounds derived from plants represent significant resources for green technologies of adsorbents and future tools. Since existing phenolic compounds are distributed worldwide, namely condensed tannins and hydrolyzable tannic acid. In particular, recent studies on their interactions with metal ions are summarized and analyzed for the utilization of adsorbents. In addition, the preparation methods of adsorbents and recovery/separation agents were outlined for the removal of hazardous, radioactive, precious, and rare metals along with their performance. Finally, the self-assembly technology of the emerging metal-polyphenol network (MPN) was described, as well as the research and development of new electronic devices were also discussed.