Efficient Approaches on Photochemical CO2 Reduction to Alcohol by Solar Light with Functional Multi-layered Membrane Catalysts

Simple and efficient approach for artificial photosynthesis of CO2 reduction into ethanol with flexible functional multi-layered membrane catalysts is suggested. The g-C3N4 and BiVO4 particle were synthesized by self-condensation and hydrothermal method. g-C3N4 membrane catalyst and g-C3N4/BiVO4 layered membrane catalyst were fabricated by casting and shaping of Nafion polymer mixture. XRD, FT-IR and XPS analyses proved that the intrinsic properties of g-C3N4 and BiVO4 were maintained after fabricating flexible functional multi-layered membrane catalyst. The interfacial contact between g-C3N4 and BiVO4 particles in flexible membrane catalyst for efficient transport of photogenerated electron was revealed by TEM and photoelectrochemical analysis. Finally, photochemical CO2 reduction reaction was performed with flexible functional multi-layered membrane catalysts. The g-C3N4 membrane catalysts produced 147 mu M of ethanol during 12 hrs of CO2 reduction reaction while the g-C3N4/BiVO4 layered membrane catalysts produced 256 mu M of ethanol during 12 hrs of CO2 reduction reaction. This is due to the higher solar light harvesting and efficient hole-charge separation from functional multi-layered BiVO4 membrane catalyst leading to the higher electron transport rate to g-C3N4 membrane catalysts, promoting the CO2 reduction reaction on the surface of g-C3N4 membrane catalyst.