Robust Deposition of Silver Nanoparticles on Paper Assisted by Polydopamine for Green and Flexible Electrodes

Technology advances in flexible and wearable electronics have promoted the booming development for high-performance flexible electrodes. In this work, we fabricated a highly conducive paper-based electrode by coating silver nanoparticles (AgNPs) on common cellulose paper using a polymer-assisted metal deposition strategy, where the mussel-inspired polydopamine (PDA) layer was applied as an interface to facilitate the bonding between paper substrates and AgNPs. Dense AgNPs can directly grow on the surface of PDA-coated paper at mild conditions, forming a highly conductive layer. The as-fabricated flexible paper electrode displays a high electrical conductivity of 4058.1 S/m and low sheet resistance of 6.5 Ω/sq, which outperforms many reported counterparts. Moreover, with the strong interfacial reinforcement by PDA, the AgNPs adhere to the paper tightly and the electrode presents a notable stability under sonication and mechanical bending. The used paper is low cost and environmentally friendly, and the preparation process is simple and green without the need of extreme conditions or strong solvents, which can be scaled up to large-scale fabrication.