Pt-Doped Biomass Carbon Decorated with MoS 2 Nanosheets as an Electrocatalyst for Hydrogen Evolution

The thermodynamically stable 2H-phase MoS 2 is a brilliant material toward hydrogen evolution reaction (HER) owing to its excellent Gibbs free energy of hydrogen adsorption. Nevertheless, the poor intrinsic properties of 2H-MoS 2 limit its electrocatalytic performances toward HER. In this work, graphitic carbon nitride covalently bridging 2H-MoS 2 (MoS 2 /GCN) is proposed to construct robust HER electrocatalysts. The strong π− p electron coupling between the delocalized π electrons of GCN and the localized p electrons of S atoms sufficiently expose active sites and accelerate the reaction kinetics. To be specific, MoS 2 / GCN exhibits remarkable HER activity (160 mV at 10 mA•cm −2 ) and long-term durability. Importantly, MoS 2 /GCN also provides great potential for industrial application. Density functional theory (DFT) calculations disclose that the π−p electron coupling at the MoS 2 /GCN interface regulates the electronic structure of S atoms, consequently providing enhanced HER performance. This work presents a feasible pathway to develop advanced electrocatalysts for energy conversions.

Section: Introductionmentioning

confidence: 99%

Interfacial π–p Electron Coupling Prompts Hydrogen Evolution Reaction Activity in Acidic Electrolyte

Jiang,

Chen,

Zhao

et al. 2024

“…In recent years, transition-metal-based nanocatalysts, such as chalcogenides, , carbides, phosphides, nitrides, and layered double hydroxides (LDHs), have been widely studied and applied in the field of electrocatalysis due to their good electrochemical properties, abundant raw materials, and mature synthesis processes. Among the many nonprecious metal-based electrocatalysts, Co-based electrocatalysts have been extensively studied and have shown potential as alternatives to precious Pt-based catalysts in term of their high catalytic ORR activity.…”

Section: Introductionmentioning

confidence: 99%

High-Density CoSe₂ Sites Embedded within 2D Porous N-Doped Carbon for High-Performance Oxygen Reduction Reaction Electrocatalysis

Chen,

Wu,

et al. 2024

Self Cite

Designing and fabricating efficient and stable nonprecious metal-based oxygen reduction reaction (ORR) electrocatalysts is a pressing and challenging task for the pursuit of sustainable new energy devices. Herein, porous P−CoSe 2 @NC electrocatalysts with high-density carbon-coated CoSe 2 sites were successfully fabricated based on a pyridyl-porphyrinic metal−organic framework (Co-TPyP MOF) via a molten salt-assisted synthesis method. The hierarchical pore and N-doping carbon substrate of P−CoSe 2 @NC promotes mass transfer and electron-transfer efficiency, which is beneficial to maximize CoSe 2 site utilization. Well-designed P−CoSe 2 @NC exhibits efficient ORR catalytic activity with a high half-wave potential of 0.863 V and excellent catalytic stability. Meanwhile, rechargeable aqueous primary/quasi-solid-state ZABs based on a P−CoSe 2 @NC air cathode show a high peak power density and exceptional operating stability, catering to the demands of practical applications. The qualified performance and structure stability of the electrocatalytic system may be mainly attributed to the protection of the CoSe 2 nanoparticle by the coated carbon layer. Given the rational design of the structure and the component of the electrocatalyst with enhanced ORR activity, we believe that this work has provided a reliable pathway to the development of high-performance transition-metal chalcogenides for energy-storage and -conversion devices.

“…To date, transition metal-based hydrogen evolution reaction (HER) electrocatalysts, like transition metal oxides, nitrides, sulfides, and phosphides, have been broadly designed and investigated, but their HER performance is still unsatisfactory. − Approaches for optimizing the HER performance of transition metal-based electrocatalysts have also been widely reported, such as nanostructure construction, heterogeneous elemental doping, interfacial engineering, and vacancy engineering. − Vacancy engineering is a strategy for modulating the structural properties of materials and modifying the chemical properties of interfaces to facilitate catalytic reactions. , In particular, the formation of vacancies for anions (O, N, S, etc.) could effectively regulate the local surface microstructure and the electron energy band structure of the catalysts, exposing more active sites and thereby promoting the ability of the active centers to adsorb the reaction intermediates. , In addition, vacancies may reduce the coordination number of adjacent atoms to create new active centers, which accelerate charge transfer and improve the conductivity of the material in multistep electrocatalytic reactions. , For instance, the sulfur-rich vacancy Cu 1.96 S/Co 9 S 8 heterostructure electrocatalyst with uniformly distributed discontinuous interfaces was fabricated by Xiao et al Due to the synergistic effect of defects and heterogeneous interfaces, the Cu 1.96 S/Co 9 S 8 heterostructure shows appropriate intermediate adsorption energies, as evidenced by the results of density functional theory (DFT) calculations.…”

Section: Introductionmentioning

confidence: 99%

Integrated Heterogeneous Engineering with the Vacancy Defect of Porous CoP_v-Mo_xP_v Nanosheets for an Accelerated Hydrogen Evolution Reaction

Qian,

Zhu,

et al. 2024

Self Cite

Electrochemical water splitting is a possible way of realizing sustainable and clean hydrogen production but is challenging, because a highly active and durable electrocatalyst is essential. In this work, we integrated heterogeneous engineering and vacancy defect strategies to design and fabricate a heterostructure electrocatalyst (CoP v -Mo x P v /CNT) with abundant phosphorus vacancies attached to carbon nanotubes (CNTs). The vacancy defects enabled the optimization of the electronic structure; thereby, the electron-rich low-valent metal sites enhanced the ability of nonmetallic P to capture proton H. Meanwhile, the heterogeneous interface between bimetallic phosphides and CNTs realized rapid electron transfer. In addition, the Co, Mo, and P active species in the electrocatalytic process exposed increased amounts of active sites featuring porous nanosheet structures, which facilitated the adsorption of reaction intermediates and thus enhanced the hydrogen evolution reaction performance. In particular, the optimized CoP v -Mo x P v /CNT catalyst possesses an overpotential of 138 mV at a current density of 10 mA cm −2 and long-term stability for 24 h. This work offers insights and possibilities for the engineering and exploration of transition metal-based electrocatalysts through combining multiple synergistic strategies.