A promising photocatalyst for water-splitting reactions with a stable sandwiched P4O2/black phosphorus heterostructure and high solar-to-hydrogen efficiency

Black phosphorus (BP) is a promising two-dimensional (2D) semiconductor, because of its tunable band gap and high hole mobility; however, its easy degradation under atmospheric conditions largely limits its application in photocatalytic water-splitting reactions. To overcome this disadvantage, we pr...

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Bibliographic Details
Published in:Nanoscale 2020-03, Vol.12 (12), p.6617-6623
Main Authors: Lu, Baichuan, Zheng, Xiaoyan, Li, Zesheng
Format: Article
Language:English
Subjects:
Atmospheric models
Electric fields
Energy gap
Excitons
First principles
Gibbs free energy
Heterostructures
Hole mobility
Phosphorus
Photocatalysis
Two dimensional materials
Water splitting
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Summary:Black phosphorus (BP) is a promising two-dimensional (2D) semiconductor, because of its tunable band gap and high hole mobility; however, its easy degradation under atmospheric conditions largely limits its application in photocatalytic water-splitting reactions. To overcome this disadvantage, we proposed a strategy for designing sandwiched P4O2-encapsulated BP (P4O2/BP) 2D materials, considering the automatic formation and high stability of P4O2 in air. We systematically considered five different packing models involving twenty sandwiched P4O2/BP systems using first-principles calculations. Through the triple screening process of 20 sandwiched P4O2/BP systems, we found that the O-1-P system with intrinsic electric field ingeniously combines all the desired features for photocatalytic water-splitting reactions, including small direct band gap (1.34 eV), low exciton binding energy, high hole mobility and ultrahigh solar-to-hydrogen efficiency as high as 22.77%. Through Gibbs free energy calculations, the active sites and possible reaction pathways of full water-splitting reactions were also confirmed. Our work offers useful guidance for designing and fabricating stable 2D materials with high performance for application in photocatalytic water-splitting reactions.
ISSN:2040-3364
2040-3372
DOI:10.1039/c9nr09942e