Harnessing Infrared Photons for Photoelectrochemical Hydrogen Generation. A PbS Quantum Dot Based "Quasi-Artificial Leaf".
Hydrogen generation by using quantum dot (QD) based heterostructures has emerged as a promising strategy to develop artificial photosynthesis devices. In the present study, we sensitize mesoporous TiO2 electrodes with in-situ-deposited PbS/CdS QDs, aiming at harvesting light in both the visible and the near-infrared for hydrogen generation. This heterostructure exhibits a remarkable photocurrent of 6 mA·cm(-2), leading to 60 mL·cm(-2)·day(-1) hydrogen generation. Most importantly, confirmation of the contribution of infrared photons to H2 generation was provided by the incident-photon-to-current-efficiency (IPCE), and the integrated current was in excellent agreement with that obtained through cyclic voltammetry. The main electronic processes (accumulation, transport, and recombination) were identified by impedance spectroscopy, which appears as a simple and reliable methodology to evaluate the limiting factors of these photoelectrodes. On the basis of this TiO2/PbS/CdS heterostructrure, a "quasi-artificial leaf" has been developed, which has proven to produce hydrogen under simulated solar illumination at (4.30 ± 0.25) mL·cm(-2)·day(-1).
†Photovoltaics and Optoelectronic Devices Group, Departament de Física, Universitat Jaume I, 12071 Castelló, Spain.
Roberto
R
Trevisan
†Photovoltaics and Optoelectronic Devices Group, Departament de Física, Universitat Jaume I, 12071 Castelló, Spain.
Pau
P
Rodenas
†Photovoltaics and Optoelectronic Devices Group, Departament de Física, Universitat Jaume I, 12071 Castelló, Spain.
Victoria
V
Gonzalez-Pedro
†Photovoltaics and Optoelectronic Devices Group, Departament de Física, Universitat Jaume I, 12071 Castelló, Spain.|‡National Institute of Lasers, Plasma and Radiation Physics, Atomistilor 409 Street, P.O. Box MG 36 Bucharest-Magurele, 077125 Romania.|§Faculty of Physics, University of Bucharest, Atomistilor 405 Street, MG-11 Bucharest-Magurele, 077125 Romania.
Cornelia
C
Sima
†Photovoltaics and Optoelectronic Devices Group, Departament de Física, Universitat Jaume I, 12071 Castelló, Spain.
Rafael S
RS
Sanchez
†Photovoltaics and Optoelectronic Devices Group, Departament de Física, Universitat Jaume I, 12071 Castelló, Spain.
Eva M
EM
Barea
†Photovoltaics and Optoelectronic Devices Group, Departament de Física, Universitat Jaume I, 12071 Castelló, Spain.
Ivan
I
Mora-Sero
†Photovoltaics and Optoelectronic Devices Group, Departament de Física, Universitat Jaume I, 12071 Castelló, Spain.
Francisco
F
Fabregat-Santiago
†Photovoltaics and Optoelectronic Devices Group, Departament de Física, Universitat Jaume I, 12071 Castelló, Spain.
Sixto
S
Gimenez
cadmium sulfide; hydrogen generation; impedance spectroscopy; lead sulfide; quantum dots; titanium dioxide