Charge Relays via Dual Carbon‐Actions on Nanostructured BiVO₄ for High Performance Photoelectrochemical Water Splitting

Abstract

Photoelectrochemical water splitting based on nanostructured bismuth vanadate (BiVO 4 ) can be a promising strategy to produce low-cost and green H 2 to replace fossil fuels and realize carbon neutrality. Herein, a simple chemical way to realize in situ carbon doping into BiVO 4 crystalline structure is designed and obtained carbon-doped BiVO 4 , namely C-BiVO 4 , can improve the electronic conductivity of BiVO 4 . In addition, the introduction of the synthesized carbon quantum dots (CQDs) as a co-catalyst, immobilizes CQDs onto the C-BiVO 4 nanosheet and acquires the optimized C-BiVO 4 /CQDs heterogeneous structure, which not only boosts light absorption, but also enhances the separation and transfer of the photo-generated charges. Stemming from the dual carbon actions, the as-prepared C-BiVO 4 /CQDs photoanode exhibits an excellent photocurrent density of 4.83 mA cm −2 at 1.23 V versus the RHE without the use of any hole scavengers. To assure the practical application of the sensitive photocatalyst, a polyaniline layer is electroplated onto the C-BiVO 4 /CQDs catalyst as a conducting, electroactive, and protective layer to sustain a remarkable long-term photocurrent density of 2.75 mA cm −2 for 9 hours. This work suggests that the proposed low-cost, environmentally friendly dual carbon actions can modify photocatalyst and achieve green production of H 2 .

Efficient Oxygen Evolution Reaction on Polyethylene Glycol‐Modified BiVO4 Photoanode by Speeding up Proton Transfer

“…IR spectrum shows a band at 2850 cm −1 assigned to the CH 2 stretching mode. Correspondingly, two bands at 1463 and 1350 cm −1 are assigned to C–H deformation modes, and the band at 1095 cm −1 belongs to C–OH stretching modes, respectively [ 35 ] (Figure 1b). The IR spectra obtained for PEG‐2000 and PEG‐6000 polymers show similar spectroscopic features as illustrated in Figure S3 of the Supporting Information.…”

Recent Progress on Photoelectrochemical Water Splitting of Graphitic Carbon Nitride (g−CN) Electrodes

“…Generally, the incorporation of a complex compound into g−CN is deemed to be a promising technique for promoting photocatalytic activity, especially for the PEC, because of the efficient carrier separation and transfer [ 218 , 219 , 220 ]. For example, BiVO 4 is an n-type semiconductor with a narrow band gap (2.4 eV), nontoxicity, low cost, and being more active in visible light [ 221 , 222 , 223 ], which is an available candidate for the development of g−CN-based heterojunction film.…”

Doping and Vacancy Engineering in a Sandwich‐like g‐C3N4/NiCo2O4 Heterostructure for Robust Oxygen Evolution

“…Unfortunately, they are limited by scarcity and high-cost. [6][7][8][9][10] Motivated by this non-negligible challenge, the relatively cheap and promising transition metal-based electrocatalysts, such as Co, Ni, Fe-based oxides, and hydroxides, are attracting enough attention. [11][12][13] For example, Zeng at al.…”