Core–Shell In/Cu₂O Nanowires Schottky Junction for Enhanced Photoelectrochemical CO₂Reduction under Visible Light

Abstract

Photoelectrochemical (PEC) CO2 reduction into chemical fuels is a promising strategy to alleviate the energy and environmental crisis. However, it remains a challenge to design efficient photocathodes for PEC CO2 reduction. Here, we constructed Cu2O-indium (In) core–shell nanowires Schottky junction assisted by physical vapor deposition to boost PEC CO2 reduction. The research of charge transport kinetics shows that the construction of Schottky junction effectively promotes the transfer and separation of photogenerated electrons. In addition, the introduction of In improves the catalytic activity of the Cu2O, and the CO yield reaches 75.94 μmol cm–2 h–1 at −0.7 V vs RHE. The In/Cu2O photocathode exhibits consistent Faradaic efficiency for CO (82%) over 12 h. In situ Fourier transformed infrared spectroscopy spectra results indicate that the introduction of In promotes the absorption and accumulation of COOH* intermediate, thereby promoting the release of CO. The study proposes a feasible strategy for designing and fabricating PEC CO2 reduction photocathodes with high catalytic activity to treat atmospheric CO2.

Controllable Preparation, Working Mechanisms, and Actual Application of Various One-Dimensional Nanomaterials as Catalysts for CO2RR: A Review

“…The traditional electrolytic cell can mainly be divided into three main components: Cathode workroom, anode workroom, and ion exchange membrane. Specifically, a cathode workroom is a place where CO 2 is reduced to expected products, such as CH 4 , C 2 H 5 OH, and so on, which are usually composed of conductive materials, catalysts, and so on. − With the role of providing electron transport pathways, some functional materials of outstanding cathode workroom should have some advantages, such as high electron conductivity, good stability, and excellent selectivity for products. ,, In the cathode workroom, it also undergoes H + electrochemical reduction (HER) to H 2 as a side reaction slightly, which can reduce the catalytic efficiency of CO 2 RR. The anode workroom is located on the other side of the cell, which also usually includes conductive material such as graphite or Ni foam.…”

“…18−21 With the role of providing electron transport pathways, some functional materials of outstanding cathode workroom should have some advantages, such as high electron conductivity, good stability, and excellent selectivity for products. 15,22,23 In the cathode workroom, it also undergoes H + electrochemical reduction (HER) to H 2 as a side reaction slightly, which can reduce the catalytic efficiency of CO 2 RR. The anode workroom is located on the other side of the cell, which also usually includes conductive material such as graphite or Ni foam.…”

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

“…Previous reports on Cu 2 O photocathodes have demonstrated selective CO 2 R in organic solvents, e.g., acetonitrile, using silver catalysts, rhenium-based molecular catalysts, or metal–organic framework (MOF) catalysts. − Using water, an abundant molecule, as the proton source for CO 2 R on the Cu 2 O photocathode is more appealing . However, many issues such as poor stability, low efficiency, , limited photocurrent and/or significant dark current − have not been solved. Energy-efficient CO 2 R on Cu 2 O-based photocathodes in an aqueous electrolyte is yet to be achieved.…”