Angew.｜MoOx/MXene hole transport layer for photoelectrochemical water oxidation

North Konami can provide MoOx/MXene hole transport layer (customizable)


Research abstract

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The development of semiconductor photoanode has important research value for realizing photoelectrochemical (PEC) water splitting. Recently, the research team of Professor Hou Jungang of Dalian University of Technology published the latest research results in "Angew. Chem. Int. Ed.". MXene quantum dots (MQDs) were loaded on BiVO4 substrates. An oxygen-reactive co-catalyst (OEC) is combined with ultrathin oxyhydroxide as an integrated photoanode. The OEC/MoOx/MQD/BiVO4 array not only achieves an areal current density of 5.85 mA cm-2 but also exhibits high stability at 1.23 V (relative to the reversible hydrogen electrode). Combined with electrochemical analysis and density functional theory calculations, the higher PEC performance is mainly due to the combination of MoOx and MQD, acting as holes in the transport layer, reducing charge recombination, promoting hole transport and accelerating water splitting kinetics . Through proof-of-concept, this paper not only demonstrates the application potential of the hole transport layer, but also provides a new idea for the rational design and fabrication of integrated photoanode for solar energy conversion.

Graphical guide







Figure 1. Schematic diagram of the integrated photoelectrochemical water splitting device; schematic diagram of the preparation process of OEC/MoOx/MQD/BiVO4.







Figure 2. SEM images of MoOx/MQD/BiVO4 and MoOx/MN/BiVO4; TEM images of BiVO4, MQD, MQD/BiVO4, MoOx/MQD/BiVO4; HR-TEM images of MoOx/MQD/BiVO4 and MN/BiVO4; Elemental distribution of MoOx/MQD/BiVO4.







Figure 3. High-resolution XPS spectra of BiVO4, MQD/BiVO4, MoOx/MQD/BiVO4.





Figure 4. Performance of different photoanodes.





Figure 5. Performance of different photoanodes: electrochemical impedance spectroscopy, Mott–Schottky plot, etc.




Figure 5. Photocurrent stability of BiVO4 and NiFeOOH/MoOx/MQD/BiVO4 photoanode, and schematic diagram of charge transport process.





Figure 5. Photosorption models and corresponding Gibbs free energies of BiVO4, MQD/BiVO4, MoOx/MQD/BiVO4



Summarize

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In this paper, a photoanode OEC/MoOx/MQD integrated with a hole transport layer was constructed by loading MXene quantum dots on BiVO4 and then depositing a MoOx layer on the composite substrate to form a photoanode, which was coupled with an ultrathin hydroxide oxygen evolution co-catalyst. /BiVO4. Manipulation of the hole transport layer is an effective strategy for the optimization of semiconductor photoanodes for PEC water splitting. This work deeply analyzes the role of the hole transport layer in the PEC system from the mechanism, and inspires new ideas for the design and fabrication of integrated photoanode for energy conversion.


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Literature link

doi.org/10.1002/anie.202200946

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