Heteroatom‐doped MoSe₂ Nanosheets with Enhanced Hydrogen Evolution Kinetics for Alkaline Water Splitting

Abstract

Electrochemical water splitting for hydrogen generation is a vital part for the prospect of future energy systems, however, the practical utilization relies on the development of highly active and earth‐abundant catalysts to boost the energy conversion efficiency as well as reduce the cost. Molybdenum diselenide (MoSe2) is a promising nonprecious metal‐based electrocatalyst for hydrogen evolution reaction (HER) in acidic media, but it exhibits inferior alkaline HER kinetics in great part due to the sluggish water adsorption/dissociation process. Herein, the alkaline HER kinetics of MoSe2 is substantially accelerated by heteroatom doping with transition metal ions. Specifically, the Ni‐doped MoSe2 nanosheets exhibit the most impressive catalytic activity in terms of lower overpotential and larger exchange current density. The density functional theory (DFT) calculation results reveal that Ni/Co doping plays a key role in facilitating water adsorption as well as optimizing hydrogen adsorption. The present work paves a new way to the development of low‐cost and efficient electrocatalysts towards alkaline HER.

Co‐Doped MoSe2 Nanoflowers as Efficient Catalysts for Electrochemical Hydrogen Evolution Reaction (HER) in Acidic and Alkaline Media

“…[6][7][8][11][12][13] High affinity of Co to the saturation of the edges of layered d-metal dichalcogenides is well established and is extensively applied in catalysis. [14][15][16] Evidence already showed that homogeneous Co doping is beneficial for the HER in both alkaline and acidic media, [17][18][19][20] since it improves both the hydrogen adsorption free energy and the water adsorption/dissociation capabilities. [17] The remaining question is whether Co doping is more efficient at the edge sites or incorporated as a substituent dopant within the layered crystal structure.…”

Phase Transitions and Water Splitting Applications of 2D Transition Metal Dichalcogenides and Metal Phosphorous Trichalcogenides

“…dopants, including Fe, [192] Zn, [197] Ni, [198] N, [199] P, [200] S, [200] etc. While attempts to promote the catalytic efficiency with the doping phase transition method also has been reported failed, for instance, Nb/Ta doped MoS 2 and WS 2 reported by Chua et al [201] Phase transition trials of obtaining T-phased TMD usually ends up in a mixture of these two phases.…”

Smart Designs of Mo Based Electrocatalysts for Hydrogen Evolution Reaction

“…To address the issues, Mo based materials can be coupled with a conductive carbon matrix to enhance electric conductivity, the dispersion of Mo sites and specific surface area [17,[47][48][49][50]. In addition, doping with heteroatoms effectively improves the intrinsic activity, lowers the kinetic energy barrier for dissociation, facilitates the charge transport and optimizes the H binding energy [26,[51][52][53][54]. Moreover, the construction of heterostructures forms a synergy and benefits the HER performances [34,55].…”

“…Nevertheless, the sluggish reaction kinetics, because of their intrinsically low activity and poor conductivity, limit their large scale applications in HER [23]. To address the issues, various modifications have been developed to improve the catalytic performances of Mo based materials, such as combination with carbon matrix, doping with heteroatoms and construction of heterostructures [24][25][26][27]. So far, most of the reviews are focused on specific Mo based compounds; a comprehensive review based on the modification strategies of Mo based electrocatalysts rather than the materials is rarely reported in HER [1][2][3][4][5].…”