Branched polymer-incorporated multi-layered heterostructured photoanode: precisely tuning directional charge transfer toward solar water oxidation

Unidirectional and smooth charge transfer to the reactive sites plays an imperative role in boosting the solar-to-hydrogen conversion efficiency of photoelectrochemical (PEC) cells but suffers from sluggish charge transfer kinetics. Herein, as a proof-of-concept demonstration, high-speed spatially s...

Full description

Saved in:
Bibliographic Details
Published in:Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2020-01, Vol.8 (1), p.177-189
Main Authors: Wei, Zhi-Quan, Dai, Xiao-Cheng, Hou, Shuo, Li, Yu-Bing, Huang, Ming-Hui, Li, Tao, Xu, Shuai, Xiao, Fang-Xing
Format: Article
Language:English
Subjects:
Assembly
Channels
Charge transfer
Charge transport
Current carriers
Electron transfer
Energy conversion
Irradiation
Kinetics
Light irradiation
Molybdenum disulfide
Multilayers
Oxidation
Photoanodes
Photovoltaic cells
Polyethyleneimine
Quantum dots
Radiation
Reaction kinetics
Solar energy
Solar energy conversion
Titanium dioxide
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Unidirectional and smooth charge transfer to the reactive sites plays an imperative role in boosting the solar-to-hydrogen conversion efficiency of photoelectrochemical (PEC) cells but suffers from sluggish charge transfer kinetics. Herein, as a proof-of-concept demonstration, high-speed spatially separated electron and hole transfer channels were simultaneously constructed in an integrated multilayered heterostructured photoanode via an efficient electrostatic layer-by-layer (LbL) assembly strategy, wherein a tailor-made positively charged polymer of branched polyethylenimine (BPEI) and negatively charged MoS 2 quantum dot (QD) building blocks were intimately and alternately integrated on the hierarchically ordered TiO 2 nanotube array (TNTA) framework in a unique "face-to-face" stacking fashion. The periodically alternately stacked ultra-thin BPEI layer in the ternary multilayered photoanode serves as a directional hole transport channel and the MoS 2 QD layer functions as a cascade electron transfer channel, which synergistically contribute to the considerably enhanced separation and prolonged lifetime of charge carriers, endowing the multilayered TNTAs/(BPEI-MoS 2 QDs) n photoanodes with markedly enhanced PEC water dissociation performances with respect to the single and binary counterparts under simulated solar light irradiation. Moreover, the essential role of the assembly unit was clarified. Our work would afford a new frontier to intelligently mediate the photoinduced charge flow by rationally constructing the unidirectional charge transport channels in semiconductor-based photoelectrodes for solar energy conversion. Two unidirectional electron and hole transfer channels were simultaneously constructed in a multilayered heterostructured photoanode via an efficient layer-by-layer assembly for solar-driven water oxidation.
ISSN:2050-7488
2050-7496
DOI:10.1039/c9ta11579j