Modulating the Cu2O Photoelectrode/Electrolyte Interface with Bilayer Surfactant Simulating Cell Membranes for Boosting Photoelectrochemical CO2 Reduction

The low solubility of CO2 molecules and thecompetitionof the hydrogen evolution reaction (HER) in aqueous electrolytes posesignificant challenges to the current photoelectrochemical (PEC) CO2 reduction reaction. In this study, inspired by the bilayerphospholipid molecular structure of cell membranes, we developed aCu(2)O/Sn photocathode that was modified with the bilayersurfactant DHAB for achieving high CO2 permeability andsuppressed HER. The Cu2O/Sn/DHAB photocathode stabilizesthe *OCHO intermediate and facilitates the production of HCOOH. Ourfindings show that the Faradaic efficiency (FE) of HCOOH by the Cu2O/Sn/DHAB photoelectrode is 83.3%, significantly higher thanthat achieved with the Cu2O photoelectrode (FEHCOOH = 30.1%). Furthermore, the FEH2 produced by the Cu2O/Sn/DHAB photoelectrode is only 2.95% at -0.6 V vsRHE. The generation rate of HCOOH by the Cu2O/Sn/DHAB photoelectrodereaches 1.52 mmol & BULL;cm(-2)& BULL;h(-1)& BULL;L-1 at -0.7 V vs RHE. Our study providesa novel approach for the design of efficient photocathodes for CO2 reduction.

Automated summary

Inspired by the bilayer phospholipid molecular structure of cell membranes, a Cu(2)O/Sn photocathode modified with the bilayer surfactant DHAB was developed to achieve high CO2 permeability and suppress HER. The Cu2O/Sn/DHAB photocathode stabilizes the *OCHO intermediate and facilitates the production of HCOOH.