Durable and Efficient Solar CO2-to-CO Conversion Enabled by Single-Atom Ag on Zn3(PO4)2 Cathode Coupled With a GaAs/PtSA@NiOOH Photoanode

초록

The increasing necessity to reduce human-caused carbon dioxide (CO2) emissions and shift to renewable fuels underscores the significance of innovative carbon-conversion methods, with photoanode-assisted CO2 reduction (photoanode-CO2RR) recently emerging as a promising strategy. This study introduces a novel interface-engineered catalyst—AgSA@Zn3(PO4)2–comprising isolated Ag single atoms (SAs) are uniformly doped onto zinc phosphate(Zn3(PO4)2) nanocubes, promoting efficient charge transfer and delivering highly selective CO production in CO2RR. Density functional theory (DFT) calculations further demonstrate that the doping of Ag SAs alters the electronic structure of Zn3(PO4)2, optimizing the adsorption of reaction intermediates. A photoelectrochemcial (PEC) flow-cell integrating a GaAs/PtSA@NiOOH photoanode and an AgSA@Zn3(PO4)2 cathode achieve carbon monoxide (CO) production with a solar-to-fuel efficiency (STF) of 4.7% and a Faradaic efficiency (FE) of 94%, demonstrating significantly improved CO2 reduction kinetics. Moreover, the integrated AgSA@Zn3(PO4)2||PtSA@NiOOH standalone photo-assisted system, powered by a photovoltaic (PV) module, operate continuously under zero external bias, achieving an average CO FECO of 90%. This outstanding performance corresponds to a solar-to-CO conversion efficiency (ηSTFco) of 8.8% under AM 1.5G illumination, showcasing its potential as an effective and durable solution for CO2 reduction.

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