Successful large-scale implementation of solar fuel technologies relies on cost, performance, and reliability of materials, devices, and infrastructures. Earth-abundant, low-cost, easily recyclable, and environmentally benign light absorbers are desired for renewable fuel generation technologies, such as solar photoelectrochemical (PEC) water splitting. Hematite is considered an ideal material for PEC oxygen evolution reaction, which is a critical component in the overall water splitting process for hydrogen fuel generation. However, intrinsic and operational limitations have prevented hematite-based PEC devices from reaching their highest theoretical solar-to-hydrogen efficiency of 15%–17%. Literature clearly shows that no single approach can eliminate these limitations. An overall fundamental understanding of the effect of dopant addition as well as their physical locations and functions within the photoelectrode, in both as-synthesized form and under operating conditions, is of critical importance to unleash the tremendous potentials of hematite-based PEC systems. In this short perspective, the concept of effective doping (i.e., increase of charge carrier density) up to the limit of dopant segregation at the grain boundaries to lower the charge recombination is discussed. Based on relevant theoretical and experimental data from the literature on the effects of surface-to-bulk doping as well as dopant segregation at the grain boundaries on hematite photoelectrode performance, we discuss here the views on the necessity of understanding these processes and their individual and synergistic effects to unravel a simple yet powerful approach to design and develop highly efficient hematite photoanodes for clean hydrogen generation using water and sunlight.
Skip Nav Destination
Article navigation
15 November 2021
Perspective|
November 17 2021
On the relevance of understanding and controlling the locations of dopants in hematite photoanodes for low-cost water splitting
Special Collection:
Materials for Renewable Fuels Production
Joao B. Souza Junior
;
Joao B. Souza Junior
a)
1
Brazilian Nanotechnology National Laboratory (LNNANO), Brazilian Center for Research in Energy and Materials (CNPEM)
, Campinas 13083-970, Brazil
Search for other works by this author on:
Flavio L. Souza
;
Flavio L. Souza
b)
1
Brazilian Nanotechnology National Laboratory (LNNANO), Brazilian Center for Research in Energy and Materials (CNPEM)
, Campinas 13083-970, Brazil
2
Centro de Ciências Naturais e Humanas (CCNH), Federal University of ABC (UFABC)
, Santo André 09210580, Brazil
Search for other works by this author on:
Lionel Vayssieres
;
Lionel Vayssieres
c)
3
International Research Center for Renewable Energy (IRCRE), State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University
, Xi'an 710049, China
Search for other works by this author on:
Oomman K. Varghese
Oomman K. Varghese
d)
4
Nanomaterials and Devices Laboratory, Department of Physics, University of Houston
, Houston, Texas 77204, USA
d)Author to whom correspondence should be addressed: okvarghese@uh.edu
Search for other works by this author on:
d)Author to whom correspondence should be addressed: okvarghese@uh.edu
Appl. Phys. Lett. 119, 200501 (2021)
Article history
Received:
August 13 2021
Accepted:
November 01 2021
Citation
Joao B. Souza Junior, Flavio L. Souza, Lionel Vayssieres, Oomman K. Varghese; On the relevance of understanding and controlling the locations of dopants in hematite photoanodes for low-cost water splitting. Appl. Phys. Lett. 15 November 2021; 119 (20): 200501. https://doi.org/10.1063/5.0066931
Download citation file:
Sign in
Don't already have an account? Register
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Pay-Per-View Access
$40.00
Citing articles via
Topological and chiral matter—Physics and applications
Maia G. Vergniory, Takeshi Kondo, et al.
Roadmap on photonic metasurfaces
Sebastian A. Schulz, Rupert. F. Oulton, et al.
Feedback cooling of an insulating high-Q diamagnetically levitated plate
S. Tian, K. Jadeja, et al.
Related Content
Strategies to improve the photoelectrochemical performance of hematite nanorod-based photoanodes
APL Mater. (April 2020)
Potential and pitfalls: On the use of transient absorption spectroscopy for in situ and operando studies of photoelectrodes
J. Chem. Phys. (October 2020)
Atomic force microscopy: Emerging illuminated and operando techniques for solar fuel research
J. Chem. Phys. (July 2020)
Semiconducting metal oxides empowered by graphene and its derivatives: Progresses and critical perspective on selected functional applications
J. Appl. Phys. (November 2020)
Photoelectrochemical cells for solar hydrogen production: Challenges and opportunities
APL Mater. (August 2019)