Facile Synthesis of MoS_x and MoS_x‐rGO Composite: Excellent Electrocatalyst for Hydrogen Evolution Reaction

Abstract

In this work, one pot synthetic methodology was developed, wherein simple purging of H2S gas into a solution/dispersion of polyoxometalates in the absence as well as presence of reduced graphene oxide (rGO) at room temperature resulted in the formation of MoSx and MoSx‐rGO composites. Powder XRD, TEM, EDS elemental analysis, TGA, and XPS study reveal that as prepared samples mainly consist of nanocrystalline MoS3 particles whereas annealed samples mainly contain few layers of MoS2 nanosheets. Annealed samples exhibit better electrocatalytic activity towards hydrogen evolution reaction (HER) as compared to the as‐prepared samples. Among all the annealed samples, MoS2‐rGO nanocomposite exhibits superior catalytic activity for HER with lower onset overpotential and higher current density, as compared to other conventional MoS2. The Tafel slope of 41.7 mV/decade for MoS2‐rGO nanocomposite signifies that MoS2 catalyzed HER follows the Volmer‐Heyrovsky mechanism wherein, electrochemical desorption of hydrogen is the rate‐limiting step. Moreover, the integration of few layers of MoS2 and rGO enable remarkable long‐term electrochemical stability and showing negligible change in the current density even after 3000 cycles.

Synthesis and Characterization of Amorphous Molybdenum Sulfide (MoSx)/CdIn2S4 Composite Photocatalyst: Co-Catalyst Using in the Hydrogen Evolution Reaction

“…This problem can be solved by using amorphous molybdenum sulfides (MoS x ), which have been shown to greatly activate and stabilize the hydrogen evolution reaction (HER), especially in acidic solutions. They are also expected to become substitutes for noble metals [20]. Compared with MoS 2 , MoS x can also be synthesized in a milder environment.…”

Highly Efficient and Robust MoS2 Nanoflake-Modified-TiN-Ceramic-Membrane Electrode for Electrocatalytic Hydrogen Evolution Reaction

“…This suggests that the MoS 2 /TiN-1:4 exposes ample edge sites with a high number of terminal unsaturated sulfur atoms. 42 The MoS 2 flakes in the MoS 2 /TiN-1:4 have a lamellar structure, as suggested by the TEM images (Figure 4a). The lattice fringe spacing of 0.62 nm in the HRTEM image corresponds to the plane (002) and that of 0.269 nm is assigned to the plane (100) of MoS 2 (Figure 4b), being a good match to the corresponding X-ray diffractogram of Figure 3a.…”

“…Hence, this ratio is calculated as 0.43 in the sample MoS 2 /TiN-1:4, which is lower than the ratios of MoS 2 /TiN-1:2 (0.5) and MoS 2 /TiN-1:8 (0.46). This suggests that the MoS 2 /TiN-1:4 exposes ample edge sites with a high number of terminal unsaturated sulfur atoms …”

Three‐dimensional MoSx/polyaniline@graphene heteroaerogels as electrode materials for high‐performance symmetric supercapacitors

“…The significant weight loss at about 700 C was due to the thermal-oxidative conversion of MoS x into MoO 3 . 36 The electrochemical behavior of the resultant nanohybrid electrode material was tested in a three-electrode cell, and CV plots were recorded between the potential window of À0.2 to 0.8 V under different scanning rates (Figure 5A,B). Figure 5A depicts the CV comparison between the PANI/RGO, MoS x /RGO, and 3D MoS x -PANI@RGO electrodes measured at a scan rate of…”