Fig. 1: Bias-induced polymerization and depolymerization at the solution–solid interface.

a Schematic showing the 2D polymerization TPBA. STM images depicting the bias-dependent polymerization and depolymerization of TPBA at the OA–graphite interface. At positive substrate bias, a SAMN is formed (b, 11 nm × 11 nm) whereas at negative bias, the formation of boroxine-linked 2D polymer (c, 11 nm × 11 nm) is observed. The bias-induced (de)polymerization also depends on the choice of the solvent and the concentration of monomers in the solution. Corresponding molecular models for SAMN (d) and 2DP (e).