Unique three-dimensional Mo2C@MoS2 heterojunction nanostructure with S vacancies as outstanding all-pH range electrocatalyst for hydrogen evolution

Defects Enhance the Electrocatalytic Hydrogen Evolution Properties of MoS2‐based Materials

“…Other defective MoS 2 -based hydrogen evolution electrocatalysts with heterostructures synthesized by high-temperature annealing include defect-rich heterogeneous MoS 2 /NiS 2 nanosheets directly made on carbon cloth [54] and three-dimensional Mo 2 C@MoS 2 heterojunction nanostructures with Svacancies. [55] Nevertheless, CVD usually produces nanostructured MoS 2 that does not contain defects. Meanwhile, the use of hightemperature annealing to achieve heteroatom doping may introduce defects, but the high temperatures and pressures required limit its practical applicability to making defect-rich MoS 2 .…”

Boosting pH‐Universal Hydrogen Evolution of Molybdenum Disulfide Particles by Interfacial Engineering†

“…Especially, considering that different water electrolysis technologies usually demand the electrolytes with different pH values, it is essential to develop robust electrocatalysts to work efficiently under wide pH ranges. [ 34,36,41‐42 ] As shown in Figure 4, this hybrid catalyst also shows intriguing pH universality for hydrogen evolution featured by overpotentials of 93 and 94 mV to afford –10 mA/cm 2 in 0.5 M H 2 SO 4 (pH=0.3) (Figure 4a) and 1 M PBS (pH=7.0) (Figure 4d) electrolytes, respectively. It is worth noting that among all the reported MoS 2 ‐based catalysts in neutral media, [ 36,43 ] this is possibly the most efficient catalyst for neutral water electrolysis.…”

“…[ 34,36,41‐42 ] As shown in Figure 4, this hybrid catalyst also shows intriguing pH universality for hydrogen evolution featured by overpotentials of 93 and 94 mV to afford –10 mA/cm 2 in 0.5 M H 2 SO 4 (pH=0.3) (Figure 4a) and 1 M PBS (pH=7.0) (Figure 4d) electrolytes, respectively. It is worth noting that among all the reported MoS 2 ‐based catalysts in neutral media, [ 36,43 ] this is possibly the most efficient catalyst for neutral water electrolysis. This catalyst also outperforms some other non‐noble electrocatalysts including CoP/CC (209 mV), [ 44 ] CoP 3 NAs/CFP (165 mV), [ 45 ] CoP NW/Hb (121 mV), [ 46 ] CoMoS 4 NS/CC (183 mV), [ 47 ] etc ., but still far inferior to some state‐of‐the‐art non‐noble electrocatalysts, such as CoP/Co‐MOF (49 mV), [ 41 ] NiCo 2 P x (63 mV), [ 42 ] and so on.…”

“…However, very few of them show promising activity in neutral medium or exhibit superb pH universality in different pH electrolytes. Considering that different water sources on earth can be served as the natural electrolytes for water electrolysis, and different water electrolysis technologies require electrocatalysts to be operated actively under a wide pH range, [ 34‐36 ] it is highly desirable to develop layered catalysts for the HER with exciting pH universality in different electrolytes.…”

Melamine-assisted synthesis of ultrafine Mo2C/Mo2N@N-doped carbon nanofibers for enhanced alkaline hydrogen evolution reaction activity

“…The Mo 2 C nanoparticles possess high electrocatalytic activity and the N-doped CNTs ensure fast electron transfer. It is generally considered that electrocatalytic reactions always occur at the surface and interface, so the electrocatalytic properties essentially depend on the composition and surface structure, which are always associated with heterostructure, element doping and ultrafine nanosize [28][29][30]. Therefore, to maximize the utilization of electrocatalysts, ultrafine Mo 2 C or Mo 2 N crystals are expected to expose more edge sites.…”