Study of the deposition of a cobalt(II)tetrasulfophthalocyanine layer at gold surfaces in alkaline solution

Study of the deposition and characterisation of a 5,10,15,20-tetrakis-(4-sulphonatophenyl)porphyrin Co(II) layer at gold surfaces in alkaline solution

“…2. The voltammetric behaviour is similar, but not identical, to the behaviour of a gold electrode in a CoTSPc (cobalt(II) tetrasulphonated phthalocyanine sodium salt) solution [9]. In what follows, the differences between both molecules concerning their electrochemistry will be explained.…”

“…3 shows curves obtained after scan 19, from scan 19 (curve 1) to scan 100 (curve 4). It is remarkable that oxidation Similar to the CoTSPc study [9], scan 19 can be considered as the scan of maximum coverage. Before scan 19, peaks C a and C c , as well as processes D a and D c , can be attributed to the ring reduction and oxidation of CoTSPor in solution.…”

Non-destructive characterization of CoTSPc electrochemically deposited on gold electrodes by means of synchrotron X-ray microfluorescence

“…2 shows some of the 100 cyclic voltammetric scans subsequently and continuously recorded at a gold electrode in order to create an electrochemically modified CoTSPc gold electrode. A detailed explanation of all electrochemical processes can be found in the literature [12,13]. Only the reduction peak at À0.38 V vs. SCE (Co(III)TSPc ads /Co(II)TSPc ads ) is relevant for this study.…”

“…Once the saturation of deposited CoTSPc is obtained (scan 17), a reorganization of the chaotic multilayer takes place towards a more stable and ordered multilayer structure of CoTSPc molecules (columnar aggregates) [12,13]. Table 1 shows the derived charges related to the Co(III) ads /Co(II) ads reduction, after a background correction, indicating the increase of the charge with growing number of voltammetric scans before the breaking point and the stabilization after scan 17.…”

“…By measuring the current as a function of potential and applied number of cycles, it is possible to follow the adsorption process in situ. In previous articles of the authors, the deposition of cobalt(II) tetrasulphonated phthalocyanine (CoTSPc) on gold surfaces in alkaline solution is well described [12,13]. According to the authors, a detailed study of the morphology and heterogeneity of the deposited phthalocyanine layer as a function of scan number has not yet been described.…”