Photoassisted CO2 Conversion to Fuels

Abstract

AbstractIn the context of the on‐going change from fossil fuels to renewable energy sources, there is much interest in decreasing atmospheric CO2 emissions. One of the possibilities is to use CO2 as feedstock of fuels and chemicals. While some catalytic CO2 transformations are well known processes, they consume a considerable amount of energy to occur at significant rates and in the classical processes this energy is again produced by burning fossil fuels. For this reason, there is much current interest in developing light assisted CO2 transformations, including, but not limited to, artificial photosynthesis. Rather than a comprehensive review, the present article describes a range of approaches for CO2 activation based either on the direct CO2 excitation with deep UV light or on the use of solar photocatalysts. Due to the extension of the field, this article is focused on two photocatalyst types, namely, TiO2 containing plasmonic Au nanoparticles and graphene‐semiconductor heterojunctions. It will be emphasized the opportunities that bimetallic plasmonic nanoparticles offer to implement on commercial TiO2 visible light photoresponse and selectivity towards CO2 reduction. It will also be commented that adsorption of Cu2O onto defective graphene increases the photocatalytic activity of the copper semiconductor over one order of magnitude for CO2 photomethanation. The last section includes some comments about possible alternatives to go beyond the current efficiencies in light assisted CO2 conversion with the aim of triggering new research in the area.