Toward CO2 utilization for direct power generation using an integrated system consisting of CO2 photoreduction with 3D TiO2/Ni-foam and a photocatalytic fuel cell

Abstract

Carbon dioxide (CO2) significantly contributes to global warming. To effectively remedy the CO2 emission and simultaneously meet the global energy demand, CO2 photoreduction to solar fuels has been considered as one of the promising approaches. However, the post-use of the hydrocarbons generated by the CO2 photoreduction usually suffers from low yield and poor selectivity. In this work, therefore, we develop an integrated system consisting of CO2 photoreduction with 3D TiO2/Ni-foam and a photocatalytic fuel cell for direct power generation. Such an integration allows the generated hydrocarbons by the CO2 photoreduction to be directly used as fuels for the photocatalytic fuel cell, realizing direct power by generation using CO2. Moreover, the 3D TiO2/Ni-foam as the photocatalyst for the CO2 photoreduction can provide a large surface area for loading the photocatalyst and its highly porous structure can significantly enhance mass transport and avail light scattering, both of which facilitate the photocatalytic reaction of CO2 and thereby enhance power output. The results confirm that the use of CO2 for direct power generation is successfully enabled by this integrated system. This work not only demonstrates the feasibility of the integrated system for direct power generation but also provides a new avenue for effective CO2 utilization.