Photoelectrochemical CO₂ Reduction via Cu₂O/CuFeO₂ Hierarchical nanorods photocatalyst

Abstract

Although cuprous oxide, Cu 2 O, has attracted attention as a promising p-type semiconductor material for carbon dioxide reduction (CO 2 RR) photocatalysts, serious stability problems have always occurred due to photocorrosion. In this work, we fabricated hierarchical-structured photocathodes with CuFeO 2 on Cu 2 O nanorods by spray pyrolysis and oxygen-controlled heat treatment to improve the stability of Cu 2 O from a thermodynamic perspective. Field-emission scanning electron microscopy, field-emission transmission electron microscopy and X-ray diffraction confirmed that the Cu 2 O/CuFeO 2 hierarchical nanorod structure was successfully fabricated. It was observed that the photocathodes show enhanced stability as the Fe content increases. Therefore, we report that the CuFeO 2 layer enhances the stability of the Cu 2 O nanorod photocathode. A photocathode with a Cu : Fe atomic ratio of 1.52 : 1 has a current density of 1.1 mA/cm 2 at 0.35 V RHE even after 10 linear voltage sweep repetitions, a decrease of only 8 % compared to the current density at the first sweep. Additionally, formate and acetate were produced during the CO 2 RR, exhibiting faradaic efficiencies (FEs) of 21.6 % and 68.6 %, respectively.

Aminopolysiloxane as Cu2O Photocathode Overlayer: Photocorrosion Inhibitor and Low Overpotential CO2‐to‐formate Selectivity Promoter

“…The origin of both photoactivity/photoinstability of cuprous oxide, as well as, strategies for stabilization can be found in the literature [6] and includes the association with different semiconductors [7,8] or the deposition of protective layers [9] . These strategies provide higher photocurrent and extend the lifetime of Cu 2 O electrodes when submitted to cathodic polarization and visible light irradiation.…”

Porous framework-based hybrid materials for solar-to-chemical energy conversion: from powder photocatalysts to photoelectrodes

“…While CdS can allow photocatalytic OER and HER (or CO2RR) at the same time, 149 Si and Cu 2 O can only allow photocatalytic HER (or CO2RR). 150,151 Unfortunately, these materials are highly unstable in aqueous solution. For example, CdS and Cu 2 O are easily photocorroded and deactivated.…”

Enhancement of Cocatalyst‐Coated ZnFe2O4 Photoanode Grown In Situ on a Metallic Iron Substrate

“…[3] Typically, the vital chemical substance NH 3 and high value-added carbon-containing compound can be synthesized by using PEC cell fixation of N 2 and CO 2 , or oxidation of glycerol under solar irradiation. [4][5][6] Among different PEC processes, the solar-driven water splitting is an encouraging approach to generate the renewable energy carrier hydrogen. [7] The semiconducting photoelectrodes as the core component of PEC cell play decisive roles to achieve high solar-tohydrogen conversion efficiency.…”

“…[8,9] Enormous attempts have been made to investigate the semiconducting oxides owing to their stability, abundance and narrow band gap for harvesting visible light to develop prospective photoelectrode materials. [10,11] TiO 2 , Fe 2 O 3 , CuWO 4 and BiVO 4 are some typical n-type semiconducting photoanodes. [12][13][14] Despite the dazzling advancement of many oxides, it remains challenging to identify a suitable material fulfill the operational requirements.…”

“…A PEC cell not only produces useful chemicals but also stores the energy into chemical bonds by absorbing sunlight [3] . Typically, the vital chemical substance NH 3 and high value‐added carbon‐containing compound can be synthesized by using PEC cell fixation of N 2 and CO 2 , or oxidation of glycerol under solar irradiation [4–6] . Among different PEC processes, the solar‐driven water splitting is an encouraging approach to generate the renewable energy carrier hydrogen [7] …”