The main scientific objective of performed studies was development of methodology for electrochemical synthesis of ternary composite materials in the Cu-Cu₂O-CNT/CNF systems (CNT – carbon nanotubes, CNF – carbon nanofibers). Copper is the only metal that exhibits very high selectivity for electrochemical conversion of CO₂ to ethylene (1). Ren et al. observed similar effect in case of p-type Cu₂O (2). Reported effects allows on assumption that combination of both materials can be great solution in the frame of light supported electrochemical conversion of carbon dioxide to ethylene. Additionally application of carbon structures: CNT or CNF as charge transfer mediators can limit photodegradation of Cu₂O, improving simultaneously its chemical stability (3) and catalytic activity as well as selectivity for electrochemical conversion of CO₂ to ethylene (2). Presence of highly hydrophobic CNT/CNF phase in Cu matrix may significantly improve selectivity through limiting adsorption of polar water molecules favoring simultaneously adsorption of nonpolar CO₂ molecules.

Present studies describing optimization of electrochemical synthesis process towards synthesis of composite coatings of wide composition range. Synthesis conditions were investigated starting from thermodynamic analysis of the electrolyte. In next step, based on zeta potentials values stability of colloidal electrolyte containing carbon nanotubes was analyzed. Current-voltage conditions allowing on deposition of Cu with Cu₂O with simultaneous incorporation of CNT/CNF structures were determined based on voltammetric and elctrogravimetric tests. Synthesized coatings were characterized towards their composition, structure and morphology.

References

1. Y. Kwon, Y. Lum, E. L. Clark, J. W. Ager and A. T. Bell, ChemElectroChem, 3, 1012 (2016).
2. D. Ren, Y. Deng, A. D. Handoko, C. S. Chen, S. Malkhandi and B. S. Yeo, ACS Catalysis, 5, 2814 (2015).
3. P. D. Tran, S. K. Batabyal, S. S. Pramana, J. Barber, L. H. Wong and S. C. J. Loo, Nanoscale, 4, 3875 (2012).