In-Situ Growth of Few-Layered MoS₂ Nanosheets on Highly Porous Carbon Aerogel as Advanced Electrocatalysts for Hydrogen Evolution Reaction

Molybdenum disulfide-based hybrids, acting as cost-effective and acid-stable electrocatalysts for hydrogen evolution reaction (HER), have been developed fast for providing sustainable hydrogen energy in recent years. Herein, few-layered molybdenum disulfide (MoS₂) nanosheets/carbon aerogel (CA) hybrids were successfully obtained through the combination of sol–gel process, aging, freeze-drying, high temperature carbonization, and solvothermal reaction. CA with highly continuous porosity and high specific surface area is used as a matrix material for construction of hierarchical MoS₂/CA hybrids where few-layered MoS₂ nanosheets are uniformly covered on a CA surface. In this heterostructured system, CAs not only provide three-dimensional (3D) conductive pathway for fast transportation of electrons and ions, but also offer highly active regions for the growth of MoS₂, greatly preventing the aggregation of MoS₂ nanosheets. Due to the rationally designed hybrids with 3D porous nanostructures, the as-prepared MoS₂/CA hybrids with optimized MoS₂ content exhibit enhanced catalytic performance for electrocatalytic HER with a low onset potential of −0.14 V, large current density, and excellent stability

Cotton Wool Derived Carbon Fiber Aerogel Supported Few-Layered MoSe₂ Nanosheets As Efficient Electrocatalysts for Hydrogen Evolution

Recent studies have proven that newly emerging two-dimensional molybdenum diselenide (MoSe₂) is a promising noble-metal-free electrocatalyst for hydrogen evolution reaction (HER). Increasing the exposures of the active edges of MoSe₂ nanostructures is a key issue to fully realize the excellent electrochemical properties of MoSe₂. In this work, a few-layered MoSe₂/carbon fiber aerogel (CFA) hybrids have been facilely obtained through the combination of high-temperature carbonization and one-pot solvothermal reaction. CFA derived from cotton wool is used as a three-dimensional conductive network for construction of hierarchical MoSe₂/CFA hybrids, where few-layered MoSe₂ nanosheets are uniformly and perpendicularly decorated on the surfaces of CFA. In the designed and prepared hybrids, CFA effectively increases the exposures of the active edges of MoSe₂ nanosheets as well as provides reduced lengths for both electron transportation and ion diffusion. Therefore, the obtained optimal MoSe₂/CFA hybrid exhibits excellent electrochemical activity as HER electrocatalyst with a small onset potential of −0.104 V vs reversible hydrogen electrode and a small Tafel slope of 62 mV per decade, showing its great potential as a next-generation Pt-free electrocatalyst for HER

Molybdenum Carbide Anchored on Graphene Nanoribbons as Highly Efficient All-pH Hydrogen Evolution Reaction Electrocatalyst

The demand for exploiting hydrogen as a new energy source has driven the development of feasible, efficient, and low-cost electrocatalysts for hydrogen evolution reaction (HER) in different reaction media. Herein, we report the synthesis of molybdenum carbide (Mo₂C) nanoparticles anchored on graphene nanoribbons (GNRs) as HER electrocatalyst that can function well under acidic, basic, and neutral conditions. GNRs obtained by unzipping carbon nanotubes (CNTs) display strip-like structure, offering abundant active sites for growing Mo₂C nanoparticles. Furthermore, GNRs could provide a fast electron transport pathway as well as large exposed surface area to allow full impregnation of electrolytes. Coupling with the anticorrosion feature of Mo₂C nanoparticles, the Mo₂C–GNR hybrid exhibits outstanding electrocatalytic performance in all of the acidic, basic, and neutral media, making it promising as a highly efficient electrocatalyst under conditions at all pH values