Assessing the Suitability of Copper Vanadate (Cu₁₁V₆O₂₆) for Use as a Photoanode Material for Photoelectrochemical Water Oxidation

Abstract

One of the most promising methods to store and utilize sunlight energy is to convert it into hydrogen via water splitting reaction. In this study, pure-phase Cu 11 V 6 O 26 thin film photoanodes were prepared on a FTO-coated glass substrate for the first time by a low-cost solution-based spray pyrolysis method. The optical bandgap, band positions, flatband potential, chemical composition, photocurrent onset potential, photocurrent generation, incident photon to current conversion efficiency, photoelectrochemical stability, and O 2 production Faradic efficiency of Cu 11 V 6 O 26 were systematically researched. UV−vis results showed that Cu 11 V 6 O 26 has an ideal bandgap of ∼1.85 eV, which corresponds to a theoretical photocurrent of up to 15 mA/cm 2 for solar water splitting. Photoelectrochemical measurements showed the onset of a photoanodic current driven under AM 1.5 illumination and reaching incident-photon-to-current efficiencies exceeding ∼4% in near-neutral (pH 6.8) aqueous solutions. Meanwhile, the Cu 11 V 6 O 26 photoelectrodes showed excellent photoelectrochemical stability and nearly quantitative Faradic efficiency, which suggest that Cu 11 V 6 O 26 could be a promising photoanode material. The results of this study will significantly increase our fundamental understanding of Cu 11 V 6 O 26 performance in solar water splitting reactions. Moreover, these data could be transferred to other ternary metal oxides for the same applications.

Enhanced Photoelectrocatalytic Activity of CuO/CuNb2O6 Heterojunction Photocathodes for Efficient Solar Water Splitting

“…Among many studies, ternary copper-based metal oxides have attracted much interest since they have excellent stability, good sideband position, inexpensive pricing, and plentiful reserves. Some ptype metal oxide semiconductors such as CuRhO 2 , [12] CuFeO 2 , [13] CuBi 2 O 4 , [14] CuNb 2 O 6 , [15] Cu 11 V 6 O 26 , [16] CuAlO 2 , [17] and CuCrO 2 [18] have been studied as photocathode materials for hydrogen evolution. Among many copper-based metal oxides, CNO has attracted great interest due to its reasonable band gap value, high theoretical current density and long-term stability in water.…”

Ag-Doped CuV2O6 Nanowires for Enhanced Visible-Light Photocatalytic CO2 Reduction

“…As an n-type semiconductor, copper vanadate (denoted as CVO) has gained considerable attention for photocatalysis because of its especial laminated structure, narrow band gap (∼2 eV), excellent electrochemical property, and superior stability against photocorrosion . Stimulated by the good photocatalytic activity of CVO, various CVO materials with different stoichiometries, such as CuV 2 O 6 , Cu 2 V 2 O 7 , Cu 3 V 2 O 8 Cu 3 VO 4 , Cu 5 V 2 O 10 , and Cu 11 V 6 O 26 , have been fabricated and applied for photodecomposition of organic pollutants and photocatalytic water splitting. It was revealed that the stoichiometric ratio of Cu/V in CVO could alter its optical and electrochemical properties and in turn affect its photocatalytic performance.…”