Development of Na2Ti6O13/CuO/Cu2O heterostructures for solar photocatalytic production of low-carbon fuels

• Published in: Materials research bulletin Vol. 122; p. 110679
• Main Authors: Ibarra-Rodríguez, Luz I., Huerta-Flores, Ali M., Torres-Martínez, Leticia M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-02-2020
• Subjects: CO2photoreduction; CuO/Cu2O; Na2Ti6O13; Photocatalytic hydrogen production; Tunnel structure; Tunnel structure; CO2photoreduction; Na2Ti6O13; Photocatalytic hydrogen production; CuO/Cu2O
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2019.110679

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•Na2Ti6O13/CuO/Cu2O materials were prepared by an impregnation method.•Different proportions of CuO/Cu2O (CC) were obtained.•Cu2O favored H2 evolution while CuO enhanced CO2 photoreduction.•Na2Ti6O13-0.1% CC exhibited the best H2 production (33 μmolg-1 h-1).•Na2Ti6O13-5% CC showed the highest yield of HCHO (25 μmolg-1 h-1).
Na2Ti6O13/CuO/Cu2O materials were prepared by solid-state and impregnation method, using copper oxide as cocatalyst (CC, 0.1%–5%). The catalytic activity was evaluated for H2 evolution and CO2 reduction. XPS analysis revealed the presence of Cu2O and CuO in different proportions. Na2Ti6O13 impregnated with 0.1% of cocatalyst exhibits majoritary the Cu2O phase; while Na2Ti6O13 with 5% of cocatalyst shows mainly CuO. Electrochemical measurements showed higher photocurrent and lower resistance to charge transference in Na2Ti6O13-0.1% CC, associated with better a charge flow. Na2Ti6O13-0.1% CC exhibited the highest H2 production (33 μmol g-1 h-1) and Na2Ti6O13-5% CC showed the best CO2 conversion to CH2O (25 μmol g-1 h-1) and CH3OH (4.6 μmol g-1 h-1). A major content of Cu2O phase favored the H2 evolution by the formation of a Z-scheme, where the strong negative character of the CB of Cu2O enhances the kinetics of H2O reduction, while a higher content of CuO improved CO2 adsorption and reduction.