TY - JOUR
T1 - Prediction of direct Z-scheme H and H́-phase of MoSi2N4/MoSX (X = S, Se) van der Waals heterostructures
T2 - A promising candidate for photocatalysis
AU - Jalil, Abdul
AU - Zhao, Tingkai
AU - Kanwal, Arooba
AU - Ahmed, Ishaq
N1 - Publisher Copyright:
© 2023 Elsevier B.V.
PY - 2023/8/15
Y1 - 2023/8/15
N2 - Photocatalysis has emerged as an appealing strategy for environmental remediation and sustainable energy production. The density functional theory (DFT) approximations were employed to investigate the heterostructures (HTS) of 2H and 2H́ polymorphs of MoSi2N4/ MoSX (X = S, Se) for photocatalytic applications. To ensure their applicability for water-splitting photocatalysis, we examined the heterostructures for desirable electronic properties. The structures (except 2H́-MoSi2N4/MoSSe) have a direct Z-scheme type-II alignment which further favors the carrier separation causing hydrogen and oxygen production at distant positions. The bandgaps of structures lie within the desirable range of 1.23 to 3 eV, favoring visible light absorption. The difference in the work function of monolayers (of about 0.5 to 1 eV) develops an electric field at the interface of HTS, causing the separation of carriers. The reduction potential lies between −3.8 to −4.6 eV, while the oxidation potential lies between −5.7 to −6.2 eV. It indicates that although oxidation potentials incorporate water redox levels, reduction potentials of some HTS do not. To ensure HER, Gibbs free energies were calculated. The vacancy defects at S/Se site gave ΔGH∗ less than the catalytic threshold of 0.2 eV. Due to ultrafast charge transfer, broad spectral response, and improved photocatalytic capability due to the formation of radicals at the surface, heterostructures can act as a competitive choice over monolayers for water-splitting photocatalysis.
AB - Photocatalysis has emerged as an appealing strategy for environmental remediation and sustainable energy production. The density functional theory (DFT) approximations were employed to investigate the heterostructures (HTS) of 2H and 2H́ polymorphs of MoSi2N4/ MoSX (X = S, Se) for photocatalytic applications. To ensure their applicability for water-splitting photocatalysis, we examined the heterostructures for desirable electronic properties. The structures (except 2H́-MoSi2N4/MoSSe) have a direct Z-scheme type-II alignment which further favors the carrier separation causing hydrogen and oxygen production at distant positions. The bandgaps of structures lie within the desirable range of 1.23 to 3 eV, favoring visible light absorption. The difference in the work function of monolayers (of about 0.5 to 1 eV) develops an electric field at the interface of HTS, causing the separation of carriers. The reduction potential lies between −3.8 to −4.6 eV, while the oxidation potential lies between −5.7 to −6.2 eV. It indicates that although oxidation potentials incorporate water redox levels, reduction potentials of some HTS do not. To ensure HER, Gibbs free energies were calculated. The vacancy defects at S/Se site gave ΔGH∗ less than the catalytic threshold of 0.2 eV. Due to ultrafast charge transfer, broad spectral response, and improved photocatalytic capability due to the formation of radicals at the surface, heterostructures can act as a competitive choice over monolayers for water-splitting photocatalysis.
KW - Direct Z-scheme heterostructure
KW - Hydrogen evolution reaction
KW - Photocatalysis
UR - http://www.scopus.com/inward/record.url?scp=85163198781&partnerID=8YFLogxK
U2 - 10.1016/j.cej.2023.144239
DO - 10.1016/j.cej.2023.144239
M3 - 文章
AN - SCOPUS:85163198781
SN - 1385-8947
VL - 470
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
M1 - 144239
ER -