Cu Nanoparticles Modified Step-Scheme Cu2O/WO3 Heterojunction Nanoflakes for Visible-Light-Driven Conversion of CO2 to CH4

Abstract

In this study, Cu and Cu2O hybrid nanoparticles were synthesized onto the WO3 nanoflake film using a one-step electrodeposition method. The critical advance is the use of a heterojunction consisting of WO3 flakes and Cu2O as an innovative stack design, thereby achieving excellent performance for CO2 photoreduction with water vapor under visible light irradiation. Notably, with the modified Cu nanoparticles, the selectivity of CH4 increased from nearly 0% to 96.7%, while that of CO fell down from 94.5% to 0%. The yields of CH4, H2 and O2 reached 2.43, 0.32 and 3.45 mmol/gcat after 24 h of visible light irradiation, respectively. The boosted photocatalytic performance primarily originated from effective charge-transfer in the heterojunction and acceleration of electron-proton transfer in the presence of Cu nanoparticles. The S-scheme charge transfer mode was further proposed by the in situ-XPS measurement. In this regard, the heterojunction construction showed great significance in the design of efficient catalysts for CO2 photoreduction application.

Electrocatalytic and Photocatalytic CO2 Methanation: From Reaction Fundamentals to Catalyst Developments

“…When a semiconductor absorbs the optical energy in the photocatalysis process, the excited electrons generated in the valence band will jump to the conduction band, producing photogenerated electrons and holes for the subsequent CO 2 reduction. Semiconductor oxides such as TiO 2 , [114] WO 3 , [115] and more recently, CeO 2 , [90,108,116] are commonly used for photocatalytic CO 2 methanation. Since strong light absorption and redox ability need a narrow and a wide bandgap for photocatalysts, respectively, two or more components are often combined in one photocatalyst via a series of coupled methods, including precipitation, polyol, hydrothermal, and sol-gel methods.…”

S-Scheme Heterojunction of Cu₂O Polytope-Modified BiOI Sheet for Efficient Visible-Light-Driven CO₂ Conversion under Water Vapor

“…Cu2O was deposited on the BiOI film surface in the similar electrochemical system. The electrolyte solution was composed with 0.02 mol•L −1 copper acetate and 0.02 mol•L −1 acetic acid 54 . In typical experiment, the Cu2O deposition was processed using chronopotentiometry method with cathode current of 0.5 mA for 0.01 s. After deposition with 1500 cycles, the obtained sample was washed by water, which was named as BiOI/Cu2O-1500.…”

Sputtering-Assisted Synthesis of Copper Oxide–Titanium Oxide Nanorods and Their Photoactive Performances

“…The p-n junction generates an internal electric field that can effectively suppress the recombination of photogenerated carriers in the composite system [ 5 , 9 ]. In addition, in terms of charge transport mode, the Z scheme often appears in organic degradation, CO 2 reduction and photoelectric catalytic water splitting in heterostructured systems [ 10 ].…”