The great performance of TiO2nanotubes electrodes modified by copper(II)porphyrin in the reduction of carbon dioxide to alcohol

Abstract

This work describes the magnifique performance of Ti/TiO2 nanotubes coated by a complex of copper (II) porphyrin ([Cu(T4H3MPP)]), assigned as (Ti/TiO2NT-CuP), applied in CO2 reduction to methanol formation by photoelectrocatalysis technique (PEC). The electrochemical behavior of the Ti/TiO2NT-CuP indicates that CO2 is preconcentrated at the electrode surface under the potential of -0.8 V amplify its reduction over the semiconductor in relation to the bare electrode. The system conditions were optimized in order to form methanol and ethanol as products, resulting in 0.35 mmol L-1 of methanol and 0.033 mmol L-1 of ethanol formation after 2 h of PEC under -0.8 V and UV-vis light incidence using 0.1 mol L-1 Na2SO4 as supporting electrolyte. That was the first time that methanol formation is identified under porphyrin-based catalysts and PEC system, while ethanol was never reported before using PEC, PC, or even EC techniques. The PEC technique was compared with photocatalysis and electrocatalysis in the same conditions proving that the synergic effect generated by the coupling of light incidence and bias potential on the semiconductor drives to high chemical fuels generation.