Adlayers of 5,10,15,20-tetraphenyl-21H,23H-porphine cobalt(II) and copper(II) (CoTPP and CuTPP) formed on a Au(111) electrode by immersion into a benzene solution containing either CoTPP or CuTPP were investigated in 0.1 M HClO4 by cyclic voltammetry and in situ scanning tunneling microscopy (STM). Highly ordered arrays of CoTPP and CuTPP molecules were observed on the Au(111) surface. Highresolution STM images revealed the characteristic shape, internal molecular structure, and molecular orientation of individual CoTPP and CuTPP molecules in ordered arrays. The adlayers of CoTPP and CuTPP formed on Au(111) were in an identical packing arrangement with the same orientation. The center cobalt ion in CoTPP appeared as the brightest spot in the STM image, whereas the copper ion in CuTPP was dark. On the adlayers of highly ordered CoTPP and CuTPP molecules, O 2 reduction was carried out in 0.1 M HClO4 saturated with O2. Voltammetric results indicated that CuTPP did not catalyze the reaction, whereas the highly ordered CoTPP adlayer on Au(111) enhanced the two-electron reduction of O2 to H2O2.
Adlayers of cobalt(II) and copper(II) phthalocyanines (CoPc and CuPc) prepared on Au(111) from CoPc-
and CuPc-saturated benzene solutions were investigated in 0.1 M HClO4 by using cyclic voltammetry and in
situ scanning tunneling microscopy (STM). The CoPc-modified Au(111) electrode was found to enhance the
electrochemical reduction of O2 to H2O2, whereas the CuPc-modified Au(111) electrode showed no
electrocatalytic activity for O2 reduction. High-resolution STM images revealed the characteristic shape, internal
structure, and orientation of each CoPc and CuPc molecule in ordered domains. Both CoPc and CuPc molecules
formed three packing arrangements on Au(111) surface, i.e., one rectangular arrangement on reconstructed
Au(111) and two hexagonal arrangements on Au(111)−(1 × 1), depending on the surface coverage. The
center cobalt ion in CoPc appeared as the brightest spot in the STM image, whereas the copper ion in CuPc
appeared as a dark spot.
By immersing Au substrate into a benzene solution containing both cobalt(II) phthalocyanine (CoPc) and copper(II) tetraphenyl-21H,23H-porphine (CuTPP), a two-dimensional alternate bimolecular structure was formed on the reconstructed Au(100)-(hex) surface.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.