Streamlining CO₂ photoelectrocatalytic conversion to C2+ products using CuMg-based LDH: A single-material photocathode strategy

The photoelectrocatalytic reduction of CO2 to valuable products using renewable energy is a promising approach to address decarbonization. PEC systems rely on photocathodes composed of a photoactive phase and a catalytically active one. The integration of such heterogeneous surfaces is difficult to achieve. Herein, we propose for the first time the use of Cu-containing Layered Double Hydroxide as single-phase photocathode material for light-assisted CO2 conversion providing simultaneous light-absorption and CO2 electroreduction. Exploiting the variability in composition and CO2 affinity of LDHs CO2 conversion into C2 and C3 oxygenates have been performed in a PEC system under low applied voltage. Taking advantage of reproducible and scalable procedures single-phase materials for photoelectrodes (Cu/Mg/Al and Cu/Mg/Fe) were obtained. Characterization of structure/morphology, photoelectrochemical, and catalytic properties allowed deep understanding of the role of metal elements within LDH structure on photocathodes performances. Iron provided strong benefits to light-harvesting and electrocatalytic activity.