Polypyrrole modification on BiVO4 for photothermal-assisted photoelectrochemical water oxidation

Abstract

Bismuth vanadate (BiVO4) photoanode receives extensive attention in photoelectrochemical (PEC) water splitting. However, the high charge recombination rate, low electronic conductivity, and sluggish electrode kinetics have inhibited the PEC performance. Increasing the reaction temperature for water oxidation is an effective way to enhance the carrier kinetics of BiVO4. Herein, a polypyrrole (PPy) layer was coated on the BiVO4 film. The PPy layer could harvest the near-infrared light to elevate the temperature of the BiVO4 photoelectrode and further improve the charge separation and injection efficiencies. In addition, the conductive polymer PPy layer acted as an effective charge transfer channel to facilitate photogenerated holes moving from BiVO4 to the electrode/electrolyte interface. Therefore, PPy modification led to the significantly improved water oxidation property. After loading the cobalt-phosphate co-catalyst, the photocurrent density reached 3.64 mA·cm-2 at 1.23 V vs RHE, corresponding to the incident photon-to-current conversion efficiency of 63% at 430 nm. This work provided an effective strategy to design photothermal material assisted photoelectrode for efficient water splitting.

Photothermal effect and application of photothermal materials in photocatalysis and photoelectric catalysis

“…This provides a low-cost and high-efficiency preparation method of noblefree photocatalysts for constructing photocatalytic materials. Subramanyam et al add Bi NPs to the C 3 N 4 /Bi 2 S 3 photoanode by a drip method, and the photocurrent density of the composite can reach 7.11 mA cm -2 [116] . The surface plasmon resonance (SPR) characteristics of Bi NPs improve the light absorption and charge carrier density, which is conducive to improving the PEC performance.…”