Hydrogen evolution on different facets of δ1- MoN and δ3-MoN: Considering the adsorbed oxygen and hydroxyl by Surface Pourbaix diagrams

Which Is Better for Hydrogen Evolution on Metal@MoS2 Heterostructures from a Theoretical Perspective: Single Atom or Monolayer?

“…The SPD is a feasible approach to provide detailed coverages of *O and *OH on a catalyst at a given potential and pH in water, which has been successfully used to determine the realistic surfaces for hydrogen evolution and oxygen reduction. 34,37,38 The evidence of *O or *OH adsorbed on the surfaces of catalysts has been reported in previous experimental and theoretical work. 37,38,55−57 Here, the SPDs of 12 kinds of stable M S @ and M M @ in the last section are calculated and we mainly focus on adsorbates on the surfaces at U RHE = 0 V for the HER, as shown in Figures 3, 4, and S8.…”

“…In experiments, while considering water in the electrolyte, the realistic catalytic surfaces may be covered by adsorbates such as oxygen (*O) and hydroxyl (*OH), which will in turn affect the stabilities, real catalytic sites, and catalytic activities of the catalysts. The SPD is a feasible approach to provide detailed coverages of *O and *OH on a catalyst at a given potential and pH in water, which has been successfully used to determine the realistic surfaces for hydrogen evolution and oxygen reduction. ,, The evidence of *O or *OH adsorbed on the surfaces of catalysts has been reported in previous experimental and theoretical work. ,,− Here, the SPDs of 12 kinds of stable M S @ and M M @ in the last section are calculated and we mainly focus on adsorbates on the surfaces at U RHE = 0 V for the HER, as shown in Figures , , and S8.…”

“…Since oxygen and hydroxyl from liquid water may be adsorbed on the surfaces and thus to influence the structures and properties, the surface Pourbaix diagram (SPD) was constructed to obtain the structures with the lowest free energy at a given potential ( U SHE ) and pH, ,, and Cu M @ is taken as an example to describe the method for building SPDs, as shown in Figure S1.…”

“…The interaction between metal atoms and substrates influences not only the atomic structures but also the electronic structures and then the catalytic performance of the surfaces. − Besides, adsorbates such as oxygen (*O) and hydroxyl (*OH) species from the electrolytes may change the electronic structures of the active sites, which indeed impact the catalytic activities. − Thus, it is important to investigate the catalysts from the view of synergistic mechanism of the metal–support interaction and the water effects.…”

High excellent hydrogen evolution characteristics and novel mechanism of two-dimensional tetra-phase OsN2 and ReN2

“…This can be modeled accurately provided the solvent (water) effect is included in the simulations, as possible via Surface Pourbaix Diagram (SPD) analysis. 31,32 SPD analysis can help understand the amount of oxygen (O*) or hydroxyl (OH*) adsorbent on the catalytic surface in detail, depending on the applied electrochemical potential and the pH of the water-electrolyte. Here, we mainly focus on the electrochemical conditions under which the HER occurs, namely for an applied potential relative to a reverse hydrogen electrode of zero volts ( U RHE = 0) and acidic conditions.…”