Z-scheme Photocatalytic CO₂ Conversion on Three-Dimensional BiVO₄/Carbon-Coated Cu₂O Nanowire Arrays under Visible Light

Abstract

Cuprous oxide (Cu2O) is one of the most promising materials for photoreduction of CO2 because of its high conduction band and small band gap, which enable the production of high-potential electrons under visible-light irradiation. However, it is difficult to reduce the CO2 using a Cu2O-based photocatalyst due to fast charge recombination and low photostability. In this work, we enhanced the photocatalytic CO2 conversion activity of Cu2O by hybridization of Cu2O NWAs, carbon layers, and BiVO4 nanoparticles. By construction of a Z-scheme charge flow on a 3-D NWA structure, the BiVO4/carbon-coated Cu2O (BVO/C/Cu2O) NWAs show significantly enhanced charge separation and light harvesting property. As a result, CO formation rate of BVO/C/Cu2O was 9.4 and 4.7 times those of Cu2O mesh and Cu2O NWAs, respectively, under visible light irradiation. In addition, the material retained 98% of its initial photocatalytic CO2 conversion performance after five reaction cycles (20 h) because of the protective carbon layer and Z-schematic charge flow. We believe that this work provides a promising photocatalyst system that combines a 3-D NWA structure and a Z-scheme charge flow for efficient and stable CO2 conversion.

Selective Deposition of Cobalt and Copper Oxides on BiVO4 Facets for Enhancement of CO2 Photocatalytic Reduction to Hydrocarbons

“…The valence band (VB) of Cu 2 O is very close to the conduction band (CB) of BiVO 4 . This fact suggests a possibility of construction of the Z‐scheme photocatalysis system for reduction of CO 2 similar to the previous reports . The significant enhancement of photocatalytic CO 2 reduction can be explained by Z‐scheme charge‐transfer mechanism (Figure ).…”

Photocatalysis for Hydrogen Production and CO2 Reduction: The Case of Copper‐Catalysts

“…This was mostly done in order to compensate the fast charge recombination and prevent photocorrosion phenomena ,. A Z‐scheme charge flow system was developed by coating Cu 2 O nanowires with BiVO 4 and conductive carbon . The composites present improved charge separation and light harvesting properties while photogenerated charges maintain their high energy due to the Z‐scheme charge flow.…”

“…The composites present improved charge separation and light harvesting properties while photogenerated charges maintain their high energy due to the Z‐scheme charge flow. BiVO 4 acts as the oxidation site while the carbon layer plays the role of the electron mediator allowing the development of the Z‐scheme charge transfer . Coupling of Cu 2 O with α‐Fe 2 O 3 leads also to the formation of a Z‐scheme heterostructure .…”

Bismuth‐Based Photocatalysts for Solar Photocatalytic Carbon Dioxide Conversion

“…[188] As shown in Figure layers with poor vanadium vacancies. [192][193][194][195][196] 5.4. On the other hand, although such ac atalytic system is extremely attractive for liquid fuel generation, deactivation of BiVO 4 results in low reaction yields.…”

“…The above discussion demonstrates why BiVO 4 is aw idely known photocatalyst for photocatalytic CO 2 reduction in al iquid-phasereaction. [196][197][198][199][200][201] In addition, Bi 2 S 3 itself can also be used as ac atalystf or the photocatalytic reductiono fC O 2 .F or example, Yine tal. Gambarotta et al investigated the catalyst behavior during methanol production and showedthat BiVO 4 irreversibly lost vanadium from its structure, while bismuth oxides were deposited on the surface due to photocorrosion.…”