4. Conclusions
In this work, DFT calculations have been performed to explore the most
stable configuration, density of states, charge transfer, work function
and HER performance of Pt, Ru and Ni single atoms supported on the (010)
surface of LaTaON2 to understand the effect of metal
cocatalysts on the substrate properties. Our results reveal that all the
metal adatoms prefer the topN site on the
La-termination and the hollowLa site on the
Ta-termination. The interaction between metal adatoms and substrate is
stronger on the Ta-termination than the La-termination because of the
formation of more covalent bonds in the former. PDOS curves suggest that
nd states of metal adatoms are well mixed with the VBM and CBM of
semiconductor surface, which guarantees no impurity states in the middle
of the band gap. This can avoid the formation of recombination center of
photoinduced charge carriers. The adsorption of Pt, Ru and Ni single
atoms slightly increase the work function of La-terminated surface and
decrease the work function of Ta-terminated surface, indicating the
deposition of metal adatoms on different termination can be a possible
method to tune the work function of substrate. The deposition of Pt, Ru
and Ni single atoms activates the surface N and O atoms and importantly
decreases the |ΔG H| value of
HER.