Efficient photoelectrochemical reduction of carbon dioxide into alcohols assisted by photoanode driven water oxidation with gold nanoparticles decorated titania nanotubes

Production of small molecule alcohol via photoelectrochemical (PEC) conversion of carbon dioxide (CO2) is one of the most prominent way to reduce the atmospheric CO2 into emission freeway. In this work, a gold nanoparticle incorporated titanium dioxide nanotubes (Au@TNT) were used as a photoanode along with platinum cathode for the photoelectrochemical conversion of CO2 into methanol and ethanol with high product yield rate of 5.1 and 1.4 mM, respectively, for 2 h under AM 1.5 G illumination at the applied potential of +1 V vs. Ag/AgCl. The Au@TNTs were prepared by facile one step electrodeposition method, the introduction of Au nanoparticles on the TNT surface improve the conductivity, charge separation efficiency, improved the interfacial charge transfer process thereby reduced the recombination rate. The charge transfer mechanism in Au@TNT and the possible reaction at the electrode surface were investigated in detail.

Automated summary

In this study, a gold nanoparticle incorporated titanium dioxide nanotubes (Au@TNT) were used as a photoanode along with platinum cathode for the photoelectrochemical conversion of CO2 into methanol and ethanol with high product yield rate. The Au@TNTs were prepared by a facile one-step electrodeposition method, which improved the conductivity and charge separation efficiency on the surface of TNT, enhancing interfacial charge transfer process and reducing recombination rate. Further investigation was conducted on the charge transfer mechanism in Au@TNT and the possible reactions at the electrode surface.