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.