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

Abstract

The low solubility of CO2 molecules and the competition of the hydrogen evolution reaction (HER) in aqueous electrolytes pose significant challenges to the current photoelectrochemical (PEC) CO2 reduction reaction. In this study, inspired by the bilayer phospholipid molecular structure of cell membranes, we developed a Cu2O/Sn photocathode that was modified with the bilayer surfactant DHAB for achieving high CO2 permeability and suppressed HER. The Cu2O/Sn/DHAB photocathode stabilizes the *OCHO intermediate and facilitates the production of HCOOH. Our findings show that the Faradaic efficiency (FE) of HCOOH by the Cu2O/Sn/DHAB photoelectrode is 83.3%, significantly higher than that 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 vs RHE. The generation rate of HCOOH by the Cu2O/Sn/DHAB photoelectrode reaches 1.52 mmol·cm–2·h–1·L–1 at −0.7 V vs RHE. Our study provides a novel approach for the design of efficient photocathodes for CO2 reduction.

Built-in Electric Field-Induced Work Function Reduction in C–Co3O4 for Efficient Electrochemical Nitrogen Reduction

“…The diffraction peaks located at 17.23°, 31.80°, 34.61°, 37.10°, and 44.47° were assigned to the (111), (220), (311), (222), and (400) facets of the pure Co 3 O 4 , respectively (Figure f), which were identical to the simulation results obtained from Materials Studios . The magnified view distinctly showed peak shifting toward a lower angle at the position of (311) (Figure f), indicating a slight increase in the lattice parameter of C–Co 3 O 4 compared to Co 3 O 4 . , X-ray photoelectron spectroscopy (XPS) was applied to point out the chemical compositions and binding conditions for C–Co 3 O 4 (Figure S5), and the corresponding element content is shown in Table S1. The doping amount of C atoms is determined to be 2.56%.…”

“…17 The magnified view distinctly showed peak shifting toward a lower angle at the position of (311) (Figure 1f), indicating a slight increase in the lattice parameter of C−Co 3 O 4 compared to Co 3 O 4 . 18,19 X-ray photoelectron spectroscopy (XPS) was applied to point out the chemical compositions and binding conditions for C− Co 3 O 4 (Figure S5), and the corresponding element content is shown in Table S1. The doping amount of C atoms is determined to be 2.56%.…”

Efficient Cu2O Photocathodes for Aqueous Photoelectrochemical CO2 Reduction to Formate and Syngas

“…Considerable efforts have been made in integrating Sn-based catalysts with various photocathodes, such as Si/TiO 2, Si/GaN, and Si nanowires. , However, previous works involving Si photocathodes generally required a large external potential (< −0.33 V vs RHE) to improve the activity for PEC–CO 2 R. Latest reports on Cu 2 O-based photocathodes with Sn catalysts have encountered similar challenges, accompanied with significant dark current that surpassed the photocurrent by 10 times. , Therefore, developing energy-efficient photocathodes with considerable photocurrent densities for PEC–CO 2 R is an urgent research goal for advancing the field.…”

Single-atom nickel sites boosting Si nanowires for photoelectrocatalytic CO2 conversion with nearly 100% selectivity

“…2,3 In this process, p-type semiconductors are used as photocathodes during the CO 2 reduction process. 4 However, the p-type semiconductors are still restricted by various factors, such as low selectivity and poor stability. Therefore, it is of great significance to develop efficient and stable p-type semiconductor materials.…”