Ultrahigh length-to-diameter ratio nickel phosphide nanowires as pH-wide electrocatalyst for efficient hydrogen evolution

Metal-doped Mo2C (metal = Fe, Co, Ni, Cu) as catalysts on TiO2 for photocatalytic hydrogen evolution in neutral solution

“…Figure 4b gives the corresponding Tafel slopes of the samples. For the commercial 20% Pt/C, the Tafel slope is 48.8 mV/dec, which is consistent with literature reports [18,19]. For the Mo2C-based samples, the Tafel slopes are 102, 56, 42, 43, and 40 mV/dec for the bare Mo2C, Fe-Mo2C, Co-Mo2C, Ni-Mo2C, and Cu-Mo2C (as shown in Table 1), respectively.…”

“…For the typical HER, there are three steps: (1) Previous experimental and theoretical studies have shown that water dissociation plays a significant role in achieving an efficient HER in neutral media [11][12][13][14]. An efficient approach to improving the kinetics of water dissociation involves accelerating the breaking of H-OH bonds by creating more surface-active sites [15][16][17][18]. Although the general design principle for achieving enhanced neutral HER efficiency has been regarded as accelerated water dissociation, design rules for developing more efficient neutral catalysts are still needed.…”

“…Besides the nature of the electrolyte and the electrode, the interface between them also determines the performance of the electrocatalyst, and thus, its character relates to the external expression of the activity [18][19][20]. In the semiconductor-solution interface, there is a classical model of carrier migration and reaction [21][22][23]; the initial energy difference between the Fermi level (Efermi) of the semiconductor and the value of the redox couple is the intrinsic factor essential for ultimate performance [22,24,25].…”

One‐step synthesis of anionic S‐substitution toward Ni 2 P (S) nanowires on nickel foam for enhanced hydrogen evolution reaction

“…To date, various transition metal alloys, 9,10 sulfides, 11‐13 phosphides, 14‐16 nitrides, 17,18 and carbides 19,20 have attracted widespread interest as efficient and low‐cost electrocatalysts suitable for the HER. Among them, transitional metal phosphides (TMPs), such as nickel phosphides, have received a significant amount of attention because of their hydrogenase‐like reactivity, good conductive properties, and electrochemical stability 21,22 . Nevertheless, the electrocatalytic performance of TMPs leaves much to be desired when compared to Pt‐based materials.…”

“…Hence, it is highly desirable to fabricate S‐substituted nickel phosphide 1D structures with a large aspect ratio on 3D conductive substrates for further improving the catalytic performance. This configuration not only provides high‐speed pathways for electron transfer but also contributes to the desorption of hydrogen bubbles accumulated on the surface of the catalysts, 21,34 thus increasing the contact area between the active sites and electrolyte.…”