Feng Li

Oxidative etching of plasmonic nanoparticles provides an effective approach to the variation of their morphology and optical properties, yet polymer ligands are generally treated as passive steric barriers. Here, we show that polymer molecules end‐grafted to the surface of penta‐twinned gold nanorods (AuNRs) perform as active interfacial regulators controlling defect‐selective oxidative metal etching. Through a combination of experiments and simulations, we show that polymer brushes localize etchant ions on the AuNR surface, lowering the energetic barrier for Au atom removal at defect‐rich regions. This defect–ligand interplay leads to the emergence of surface corrugations along the AuNR longitudinal facets, in stark contrast to the etching behavior of single‐crystal AuNR counterparts. By varying polymer molecular weight and grafting density, we achieve precise control of the plasmonic properties of etched AuNRs. These findings establish polymer brushes as active modulators of nanoscale interfacial reaction pathways, providing a strategy for defect‐directed nanoengineering with applications in catalysis, sensing, and photonics.

Oxidative etching of plasmonic nanoparticles provides an effective approach to the variation of their morphology and optical properties, yet polymer ligands are generally treated as passive steric barriers. Here, we show that polymer molecules end‐grafted to the surface of penta‐twinned gold nanorods (AuNRs) perform as active interfacial regulators controlling defect‐selective oxidative metal etching. Through a combination of experiments and simulations, we show that polymer brushes localize etchant ions on the AuNR surface, lowering the energetic barrier for Au atom removal at defect‐rich regions. This defect–ligand interplay leads to the emergence of surface corrugations along the AuNR longitudinal facets, in stark contrast to the etching behavior of single‐crystal AuNR counterparts. By varying polymer molecular weight and grafting density, we achieve precise control of the plasmonic properties of etched AuNRs. These findings establish polymer brushes as active modulators of nanoscale interfacial reaction pathways, providing a strategy for defect‐directed nanoengineering with applications in catalysis, sensing, and photonics.

Reactive capture integrates CO₂ capture and electrochemical conversion into CO - a key building block in the synthesis of industrial chemicals and fuels - avoiding costly regeneration steps and improving efficiency. Amino acid salt solutions, which offer rapid CO₂ capture, facile CO₂ release, O₂ tolerance, and low toxicity, are promising sorbents for reactive capture. However, we find that amino acids can adsorb to common CO-producing catalysts, covering the active sites and deactivating the catalyst, and that they bind less to nickel phthalocyanine (NiPc). Still, when tested for reactive capture systems - where CO₂ supply is inherently limited - NiPc's performance is constrained by its weak CO₂ adsorption and activation. Here we develop a nickel molecular catalyst supported on carbon nanotubes with a conjugated NiPc framework that resists amino acid adsorption and a coordinatively unsaturated Ni-N₃ structure that promotes CO₂ adsorption and enhances CO selectivity. As a result, we achieve 94% CO Faradaic efficiency at 100 mA cm^-2 with an energy efficiency of 42% and an energy cost of 25 GJ t_CO^-1.