Dual-functional paired photoelectrocatalytic system for the photocathodic reduction of CO2 to fuels and the anodic oxidation of furfural to value-added chemicals.

[Display omitted] • Novel Au/α-Fe 2 O 3 /RGO photocathode and Ru/RGO anode were synthesized and characterized. • Investigated half-cell PEC CO 2 reduction over Au/α-Fe 2 O 3 /RGO photocathode • Results on paired PEC CO 2 reduction efficiency coupled with the anodic oxidation of furfural were presented • Paired PEC electrolyzer enables a cost-effective process for CO 2 reduction and conversion of biomass compounds. The global warming and energy requirement have accentuated the need to convert atmospheric CO 2 into fuels through a highly efficient photoelectrochemical cell (PEC) process. Typically, CO 2 reduction at the cathode is accompanied by water oxidation at the anode to produce O 2 , which is not of significant value. Herein, we report the design of paired PEC to reduce CO 2 to CH 3 OH and the oxidation of furfural (FF) to 2-furoic acid (2-FA) and 5-hydroxyfuroic acid (5-HFA). The paired PEC electrolyzer was constructed with Au/α-Fe 2 O 3 /RGO and Ru/RGO/Pt based asymmetric electrodes. The photocathode-driven PEC CO 2 conversion test showed a high CH 3 OH yield of 63 μmol L−1 cm−2 at 21.5 % quantum efficiency with a Faradaic efficiency of 91 % at -0.6 V under visible light. The anodic furfural oxidation test demonstrated a higher FF conversion (82 %) with higher yields of 2-FA and 5-HFA. This study showed the potential of the paired PEC process to produce valuable products at both electrodes. [ABSTRACT FROM AUTHOR]