A colloidal heterostructured quantum dot sensitized carbon nanotube–TiO2 hybrid photoanode for high efficiency hydrogen generation

Autor:	Fabiola Navarro-Pardo, Gurpreet Singh Selopal, Zhiming Wang, Haiguang Zhao, Mahyar Mohammadnezhad, Federico Rosei, François Vidal
Rok vydání:	2019
Předmět:	Photocurrent Materials science Hydrogen business.industry Exciton Energy conversion efficiency chemistry.chemical_element Carbon nanotube Anode law.invention chemistry Quantum dot law Optoelectronics General Materials Science business Hydrogen production
Zdroj:	Nanoscale Horizons. 4:404-414
ISSN:	2055-6764 2055-6756
Popis:	Solar-driven photoelectrochemical (PEC) hydrogen (H2) generation is a promising approach to harvest solar energy for the production of a clean chemical fuel. However, the low photon-to-fuel conversion efficiency and long-term stability of PEC devices are major challenges to be addressed to enable large-scale commercialization. Here we report a simple, fast and cost-effective approach to fabricate high efficiency and stable PEC devices for H2 generation, by fabricating a hybrid photoanode obtained by incorporating small amounts of multiwall carbon nanotubes (MWCNTs) into a TiO2 mesoporous film and sensitizing with colloidal heterostructured CdSe/(CdSexS1-x)5/(CdS)2 quantum dots (QDs). The latter were specially designed to accelerate the exciton separation through a band engineering approach. The PEC devices based on the TiO2/QD-MWCNT (T/Q-M) hybrid photoanode with an optimized amount of MWCNTs (0.015 wt%) yield a saturated photocurrent density of 15.90 mA cm-2 (at 1.0 VRHE) under one sun illumination (AM 1.5G, 100 mW cm-2), which is 40% higher than that of the reference device based on TiO2/QD (T/Q) photoanodes. This is attributed to a synergistic effect of the promising optoelectronic properties of the colloidal heterostructured QDs and improved electron transport (reduced charge transfer resistance) within the TiO2-MWCNT hybrid anodes enabled by the directional path of MWCNTs for the photo-injected electrons towards FTO. Furthermore, the PEC device based on the T/Q-M hybrid photoanode is more stable (∼19% loss of its initial photocurrent density) when compared with the T/Q photoanode (∼35% loss) after two hours of continuous one sun illumination. Our results provide fundamental insights and a different approach to improve the efficiency and long-term stability of PEC devices and represent an essential step towards the commercialization of this emerging solar-to-fuel conversion technology.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::6b0f31c571d68a37790d980f44b75e4b https://doi.org/10.1039/c8nh00227d Zobrazit plný text záznamu