Detail:
Abstract: Recent advance in solution phase synthesis has made it possible to obtain nanoparticles (NPs) with their dimensions controlled at near-atomic precision for catalytic applications. In this talk, I highlight two examples demonstrated in our lab on the synthesis and self-assembly of Co-, and Cu-based NPs for enhanced electrocatalytic reactions. Monodisperse Co NPs were synthesized via thermal decomposition of cobalt carbonyl and assembled at water-air interface on a glass carbon (GC) plate and their catalysis for oxygen evolution reaction.These Co NPs were further stabilized against oxidation via reductive annealing at 600°C. When employed as the catalyst for electrochemical oxidation reaction in 0.1 M KOH, the monolayer Co NPs show 15 times higher turnover frequency (TOF) (2.13 s-1) and mass activity (1949 A/g) than the same NPs deposited on conventional carbon black at the overpotential of 0.4 V. These Co NPs are a promising new class of noble-metal-free catalyst for water-splitting. Monodisperse Cu NPs assembled on pyridinic-N rich graphene (p-NG) show much enhanced catalysis for selective electrochemical reduction of CO2 to ethylene (C2H4). At -0.9 V (vs reversible hydrogen electrode), the C2H4 formation Faradaic efficiency and hydrocarbon selectivity reach 19% and 79% respectively. The work demonstrates a new strategy to improve Cu NP catalytic activity and selectivity for electrochemical reduction of CO2 for sustainable chemistry and energy applications.
