Excellent HER and OER Catalyzing Performance of Se-Vacancies in Defects-Engineered PtSe2: From Simulation to Experiment

Faced with grave climate change and enormous energy demands, effective catalysts have become more and more important due to their significant effects on reducing fossil fuels consumption. The hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) by water splitting are feasible ways to produce clean sustainable energy. Here, atomic structures and related scanning tunneling microscope images of Se defects in PtSe2 are systematically explored. The equilibrium fractions of vacancies under variable conditions are predicted in detail. In addition, it is found that the vacancies are highly kinetically stable, without recovering or aggregation. The Se vacancies in PtSe2 can dramatically enhance the HER performance, comparing to Pt(111). It is also revealed that a PtSe2 monolayer with Se vacancies is also a good OER catalyst. The excellent bipolar catalysis of Se vacancies is further confirmed by experimental measurements. A defective PtSe2 made via direct selenization of Pt foil at 773 K using a chemical vapor deposition process is produced. It is shown that the HER and OER performance of defective PtSe2 is much more efficient than Pt foils by a series of measurements. This work, with its compelling theoretical and experimental studies indicates PtSe2 with Se defects is an ideal bipolar candidate for HER and OER.

Automated summary

The research shows that Se vacancies in PtSe2 can significantly enhance the efficiency of the hydrogen evolution reaction and also exhibit good catalytic properties for the oxygen evolution reaction. Defective PtSe2 produced via a chemical vapor deposition process is more efficient than Pt foils, indicating its potential for widespread applications.