While economical and effective catalysts are required
for sustainable
hydrogen production, low-dimensional interfacial engineering techniques
have been developed to improve the catalytic activity in the hydrogen
evolution reaction (HER). In this study, we used density functional
theory (DFT) calculations to measure the Gibbs free energy change
(ΔG
H) in hydrogen adsorption in
two-dimensional lateral heterostructures (LHSs) MX2/M’X’2 (MoS2/WS2, MoS2/WSe2, MoSe2/WS2, MoSe2/WSe2, MoTe2/WSe2, MoTe2/WTe2, and WS2/WSe2) and MX2/M’X’
(NbS2/ZnO, NbSe2/ZnO, NbS2/GaN, MoS2/ZnO, MoSe2/ZnO, MoS2/AlN, MoS2/GaN, and MoSe2/GaN) at several different positions near
the interface. Compared to the interfaces of LHS MX2/M’X’2 and the surfaces of the monolayer MX2 and MX,
the interfaces of LHS MX2/M’X’ display greater
hydrogen evolution reactivity due to their metallic behavior. The
hydrogen absorption is stronger at the interfaces of LHS MX2/M’X’, and that facilitates proton accessibility and
increases the usage of catalytically active sites. Here, we develop
three types of descriptors that can be used universally in 2D materials
and can explain changes in ΔG
H for
different adsorption sites in a single LHS using only the basic information
of the LHSs (type and number of neighboring atoms to the adsorption
points). Using the DFT results of the LHSs and the various experimental
data of atomic information, we trained machine learning (ML) models
with the chosen descriptors to predict promising combinations and
adsorption sites for HER catalysts among the LHSs. Our ML model achieved
an R
2 score of 0.951 (regression) and
an F
1 score of 0.749 (classification).
Furthermore, the developed surrogate model was implemented to predict
the structures in the test set and was based on confirmation from
the DFT calculations via ΔG
H values.
The LHS MoS2/ZnO is the best candidate for HER among 49
candidates considered using both DFT and ML models because it has
a ΔG
H of −0.02 eV on top
of O at the interface position and requires only −171 mV of
overpotential to obtain the standard current density (10 A/cm2).