Qingfa Wang

When Cubic Cobalt Sulfide Meets Layered Molybdenum Disulfide: A Core–Shell System Toward Synergetic Electrocatalytic Water Splitting

A new class of Co9 S8 @MoS2 core-shell structures formed on carbon nanofibers composed of cubic Co9 S8 as cores and layered MoS2 as shells is described. The core-shell design of these nanostructures allows the advantages of MoS2 and Co9 S8 to be combined, serving as a bifunctional electrocatalyst for H2 and O2 evolution.

Design of Two-Dimensional, Ultrathin MoS2 Nanoplates Fabricated Within One-Dimensional Carbon nanofibers With Thermosensitive Morphology: High-Performance Electrocatalysts For The Hydrogen Evolution Reaction

Two-dimensional MoS2 nanoplates within carbon nanofibers (CNFs) with monolayer thickness, nanometer-scale dimensions and abundant edges are fabricated. This strategy provides a well-defined pathway for the precise design of MoS2 nanomaterials, offering control over the evolution of MoS2 morphology from nanoparticles to nanoplates as well as from mono- to several-layer structures, over a lateral dimension range of 5 to 70 nm. CNFs play an important role in confining the growth of MoS2 nanoplates, leading to increases in the amount of exposed edge sites while hindering the stacking and aggregation of MoS2 layers, and accelerating electron transfer. The controlled growth of MoS2 nanoplates embedded in CNFs is leveraged to demonstrate structure-dependent catalytic activity in the hydrogen evolution reaction (HER). The results suggest that increases in the number of layers and the lateral dimension result in a decrease in HER activity as a general rule. Single-layer MoS2 nanoplates with abundant edges and a lateral dimension of 7.3 nm demonstrated the lowest hydrogen evolution reaction overpotential of 93 mV (J = 10 mA/cm(2)), the highest current density of 80.3 mA/cm(2) at η = 300 mV and the smallest Tafel slope of 42 mV/decade. The ability of MoS2-CNFs hybrids to act as nonprecious metal catalysts indicates their promise for use in energy-related electrocatalytic applications.

A 3D dendritic WSe2 catalyst grown on carbon nanofiber mats for efficient hydrogen evolution

3D dendritic WSe2 on conductive carbon nanofiber mats (d-WSe2/CFM) was designed and synthesized by a diffusion-controlled CVD method. The d-WSe2/CFM was directly used as a cathode for the HER. The substantially improved HER performance is ascribed to the novel 3D structure with effectively exposed edge sites.

Silk-derived graphene-like carbon with high electrocatalytic activity for oxygen reduction reaction

A facile method to prepare the nanoporous and graphene-like carbon material from a natural silk fiber was developed by a potassium intercalation and carbonization procedure. The as-synthesized graphene-like fiber was employed for oxygen reduction reaction and exhibited impressive electrocatalytic activity.