PHOTOELECTROCATALYTIC CONVERSION OF CO₂ AND BIOGAS INTO PRODUCTS OF ENERGY INTEREST USING Ti/TiO₂ NANOSTRUCTURED SEMICONDUCTORS MODIFIED WITH COPPER

This work describes the superficial modification of Ti/TiO₂ nanotubes by copper oxide electrochemical deposition, in different temperatures (25 and 65 ºC), and its application on the photoelectrocatalytic conversion of CO₂ and biogas in products of energy interest. The different temperatures deposition resulted in the formation of different geometric forms on the surface of Ti/TiO₂ nanotubes and in different photoelectrocatalytic activities. The photoelectrocatalytic conversion in 0.1 mol L^-1 Na₂SO₄ with application of -0.1 V and UV irradiation resulted in the formation of acetone and methanol from CO₂ and acetone and ethanol from biogas, being that the acetone production was higher for the semiconductor synthesized at 65 ºC, while the methanol and ethanol production was higher for the semiconductor at 25 ºC. The different characteristics observed, as well as the preferential formation of different products of photoelectrocatalytic reactions for semiconductors synthesized with different electrochemical deposition temperatures are discussed.

Keywords:
photoelectrocatalysis; conversion of CO₂ and biogas; modification of Ti/TiO₂ nanotubes; copper oxide