Dual Quantum Dot‐Decorated Bismuth Vanadate Photoanodes for Highly Efficient Solar Water Oxidation

Abstract

Photo‐induced charge separation and photon absorption play important roles in determining the performance of the photoelectrocatalytic water splitting process. In this work, we utilize dual quantum dots (QDs), consisting of BiVO4 and carbon, to fabricate a hybrid homojunction‐based BiVO4 photoanode for efficient and stable solar water oxidation. Formation of homojunctions, by decorating as‐prepared BiVO4 substrate with BiVO4 QDs, enhances the charge separation efficiency by 1.3 times. This enhancement originates from lattice match, which benefits charge transfer across the interface. Furthermore, the use of carbon QDs as a stable photosensitizer effectively extends the photon absorption limit from 520 nm to over 700 nm, yielding an incident photon‐to‐electron conversion efficiency of 6.0 %, even at 600 nm at 1.23 V versus RHE. Finally, a remarkable photocurrent density of 6.1 mA cm−2 at 1.23 V was recorded after depositing FeOOH/NiOOH as cocatalysts, thereby, reaching 82 % of the theoretical efficiency for BiVO4.

Black TiO2 Nanotube Array/BiVO4 Heterojunction Photocatalysts for Tetracycline Removal with High Solution Detoxification Efficiency

“…The clear visibility of lattice fringes in Figure 5c confirms the high crystallinity of the as-prepared B-TiO 2 /BiVO 4 heterostructure, and the different interplanar distance values also confirm the formation of a heterojunction between B-TiO 2 and BiVO 4 . Briefly, the distinct lattice spacings of 0.23, 0.35, and 0.31 nm are observed in the HRTEM image of the TiO 2 /BiVO 4 heterostructure, which were assigned to the (004) 41 and (101) 11 lattice planes of anatase TiO 2 and the (121) 42 plane of monoclinic BiVO 4 , respectively. Selected-area electron diffraction (SAED) revealed the main diffraction rings, which are in good agreement with the anatase phase TiO 2 (see the XRD pattern in Figure 2c).…”

A bifunctional catalyst based on a carbon quantum dots/mesoporous SrTiO3 heterostructure for cascade photoelectrochemical nitrogen reduction

“…These results indicate that the CQD surface is functionalized by –OH and –COOH, which is beneficial to the performance of catalysis. 46 The similar characteristic bands in both CQDs and CQDs/STO suggest a strong coupling between the CQDs and STO. Fig.…”

A two-photon tandem black phosphorus quantum dot-sensitized BiVO4 photoanode for solar water splitting

“…5c), all of which mainly benefit by extending the optical absorption region. [44][45][46][47][48][49][50] Through a summary of other successful strategies that enable the photocurrent density of BiVO 4 over 5 mA cm À2 (Table S2, ESI †), it is expected that the multi-component design with suppression of surface charge recombination and expanding light absorption region can also be efficient for charge separation or water oxidation kinetics leading BiVO 4 towards further enhancement in PEC performance. Since the issues of light harvesting, charge separation and sluggish kinetics, which hinder the PEC performance, have been resolved by the carefully designed BPQDs, TiO 2 OL and OEC components, the photocurrent-to-H 2 /O 2 faradaic efficiencies (FEs) were further confirmed (Fig.…”