Sulfur-doped Reduced Graphene Oxide Research Articles

Preparation and evaluation of S-rGO/ZnFe2O4/NiCoLDH nanocomposite electrocatalyst in oxygen reduction reaction

This study introduces a novel combination of sulfur-doped reduced graphene oxide (S-rGO), zinc ferrite (ZnFe2O4) and nickel cobalt layered double hydroxide (NiCoLDH) as an efficient and low-cost electrocatalyst for oxygen reduction reaction (ORR) for the first time. The hydrothermal method is used to synthesize all samples including graphene oxide (GO), S-rGO, NiCoLDH, ZnFe2O4 and S-rGO/ZnFe2O4/NiCoLDH hybrids. X-ray diffraction (XRD) analysis, field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), energy dispersive x-ray analysis (EDX), electrochemical surface area (ECSA), and fourier transform infrared spectroscopy (FTIR) analysis are used to determine the structure of synthesized electrocatalysts, physical properties, and morphology. The electrochemical measurements are carried out using cyclic voltammetry (CV), linear scanning voltammetry (LSV), chronoamperometry (ChA), and electrochemical impedance spectroscopy (EIS). The results for all samples are compared with the Pt/C commercial catalyst. According to the electrochemical results, the S-rGO/ZnFe2O4/NiCoLDH electrocatalyst has the best electrochemical performance. Moreover, the nanocomposite exhibited better electrocatalysis, a high diffusion limiting current density of −5.4 mA cm−2 and an onset potential of 0.03 V. Based on the results of this study, the LDH enhances electrical conductivity, electrocatalytic activity, active surface area, and stability of the catalyst for ORR after combining with carbon bases and ferrite.

Determination of Digoxin in Biological Samples and Medicinal Plants by Electrochemical and Chromatographic Methods

AbstractIn this study, the nanocomposite with FeS2 nanoparticles and sulfur‐doped reduced graphene oxide (SRGO) were synthesized and characterized with appropriate spectroscopic, crystallographic and morphological methods. The FeS2‐SRGO nanocomposite was coated on a glass‐carbon (GC) electrode as working electrode for the electrochemical determination of digoxin. The method was linear in the range of 3–25 μgL−1 with the detection limit of the method is 0.54 μgL−1. The plant‘s active ingredient was extracted from Leonurus cardiac and Valeriana officinalis. Three important types of real samples including plants extracted and urine samples were selected to measure the amounts of digoxin. The electrochemical sensing results were evaluated by studying the amount of spiked recovery and statistical test with comparison to the high‐performance liquid chromatography (HPLC) method results and the accuracy and precision of the method for digoxin determination in real samples were confirmed. The results show the plant extracted contained a significant amount of digoxin. The presence of digoxin in valerian was investigated for the first time in this study.

Interfacial Synthesis of Prussian Blue-Decorated Sulfur-Doped Reduced Graphene Oxide Nanocomposite for Electrochemical Sensing and Detoxification of As(III)

Interfacial Synthesis of Prussian Blue-Decorated Sulfur-Doped Reduced Graphene Oxide Nanocomposite for Electrochemical Sensing and Detoxification of As(III)

2D/2D cobalt vanadate nanoplatelets/S-doped reduced graphene oxide nanosheets composite for the detection of nonsteroidal anti-inflammatory drug: Acetaminophen

Vanadate and carbonaceous materials are being developed into a composite material because of their exciting dynamics. In this study, coprecipitation and ultrasonication strategies were followed to prepare Cobalt vanadate and sulfur-doped reduced graphene oxide (CoV/S-rGO) composite for the determination of acetaminophen (Aph) nonsteroidal anti-inflammatory drug (NSAID). Because, this NSAIDs are commonly subscribed and discharged to humans and environment, it is an essential need to detect this drug. The surface morphology studies confirm that the CoV and S-rGO have two-dimensional nanoplatelets and nanosheets structure, respectively. The electrochemical features of the CoV/S-rGO modified glassy carbon electrode was assessed using cyclic voltammetry and amperometry. In this study, we have achieved excellent sensitivity, reproducibility, selectivity, and stability with a composite electrode over a linear range of 0.01–152 µM. The sensor was further demonstrated to be practical in real-time analysis of commercial tablet samples with a satisfactory recovery rate.

S-Doped rGO-Enwrapped Magnetically Porous NiFe2O4/CuS Heterojunction: An Efficient Z-Scheme Nano-Photocatalyst for Visible-Light-Driven Tetracycline Degradation and 4-Nitrophenol Reduction

The photocatalytic degradation of economically hazardous compounds has been thoroughly researched with the aid of numerous photocatalysts and techniques. The efficient degradation and removal of lingering contaminants from the aquatic environment are still difficult to accomplish. Hereby, we present a sulfur-doped reduced graphene oxide (SrGO) enwrapped magnetic porous nickel ferrite (NiFe2O4)/copper sulfide (CuS) nanocatalyst (SrGO/NiFe2O4/CuS:GNFC) constructed through a facile solvothermal-reflux route. Under exposure to visible light, the fabricated GNFC photocatalyst exhibits outstanding catalytic activity for the photodegradation of tetracycline hydrochloride (TCH) and photoreduction of 4-nitrophenol (4-NP). Diverse analytical techniques were used to characterize the fabricated nanomaterials. In terms of photocatalytic activity, GNFC-13 outperforms all other nanocatalysts in eliminating model pollutants. According to our findings, 94.39% of TCH (80 ppm) can be degraded within 90 min, and 90.62% of 4-NP (30 ppm) can be reduced within 120 min by the GNFC-13 nanohybrid, which is significantly better than that of pristine and doublet nanomaterials, respectively. The explanations for the improved photocatalytic efficiency of GNFC nanocatalysts are due to the porous structures of the magnetic NiFe2O4 and the SrGO surface, which can offer a lot of adsorption sites and, therefore, advantageous for the adsorption enrichment of harmful pollutants. Additionally, in situ photocatalytic degradation and adsorption enrichment working together synergistically may lead to improved pollutant removal efficacy. The Raman and XPS analytical techniques verified the formation of SrGO in the GNFC nanocomposites. The free-radical trapping studies, terephthalic acid test, nitroblue tetrazolium test, and electron spin resonance test disclosed that holes (h+), hydroxy radicals (·OH), electrons (e–), and superoxide radicals (·O2–) are cardinal reactive species in the photocatalytic system. A Z-scheme charge transfer channelization mechanism of the as-produced photocatalyst is explained in light of the various experimental findings. The developed Z-scheme system has led to the increase of catalytic activity due to the effective photoinduced carrier separation, wider photoabsorption range, high hole oxidation capacity, and high electron reduction power. In addition, the GNFC photocatalyst ability to catalyze TCH and 4-NP shows no discernible decline even after five recycles. Moreover, the GNFC nanocatalysts are magnetically detachable for recycling. Thus, this study reveals that the as-obtained GNFC nanocatalysts have an excellent prospect for environmental remediation of toxic pollutants.

Comparative study on the structural and electrochemical properties of nitrogen-doped and nitrogen and sulfur co-doped reduced graphene oxide electrode prepared by hydrothermal technique

Nitrogen- and co-nitrogen- and sulfur-doped reduced graphene oxide (named N-rGO and N/S-rGO) was prepared by a simple hydrothermal technique using urea and thiourea as doping agents, respectively, to improve the properties of supercapacitor electrodes. Both were compared with rGO in electrochemical evaluations. The supercapacitor using N-rGO in 1 M H2SO4 provided the largest specific capacitance, 99 F g−1, while those using N/S-rGO and rGO exhibited 51 and 19 F g−1 at 0.25 A g−1, respectively. Furthermore, the supercapacitors using N-rGO and N/S-rGO electrodes showed a smaller charge transfer resistance (Rct) and a lower IR-drop than those using the rGO electrode, indicating a faster charge transfer at the interface between electrode and electrolyte and higher electronic conductivity due to N or N/S heteroatom doping in the graphene oxide structure. Furthermore, the N-rGO electrode has a higher sp2 hybridization ratio and a lower ID/IG ratio than the N/S-rGO electrode. Furthermore, the lowest contact angles of the N/S-rGO electrode were found, which was attributed to better aqueous electrolyte compatibility than the N-rGO and rGO electrodes. Therefore, the higher electrical conductivity of the N-rGO electrode reveals more relevant characteristics for high-performance supercapacitors than the good wettability of the N/S-rGO electrode.

Unveiling electrocatalytic performance of MnCo-P on sulfur-doped reduced graphene oxide for electrochemical detection of acetaminophen

It is well known that the overdose and prolonged use of acetaminophen (AAP) drugs could cause severe health issues for human beings. In order to prevent such health issues, it is important to electrochemically monitor the level of AAP in the human body and consumption sources such as river and lake water. In this study, we have developed an electrode modified with manganese cobalt phosphide (MnCo-P) onto sulfur-doped reduced graphene oxide (S-RGO) composite for electrochemical detection of AAP. The cyclic voltammetry analysis shows that the synergistic activity of MnCo-P and S-RGO in the MnCo-P/S-RGO composite obtained a high current responsibility towards the electrochemical detection of AAP. Further, the amperometry (i-t) analysis of MnCo-P/S-RGO for AAP demonstrated a low detection limit of 1.39 nM in the linear range of 0.05 to 1.94 µM and a sensitivity of 0.658 µA µM−1cm−2 which are appreciable. The real sample analysis recovery (%) from AAP detection in tablet, human urine, and river water samples indicates the MnCo-P/S-RGO modified electrode is significant for AAP level monitor in clinical.

Nitrogen-doped porous carbon coated on MnCo2O4 nanospheres as electrode materials for high-performance asymmetric supercapacitors

Spinel-based nanostructured materials are commonly used as promising electrode materials for supercapacitor applications. The combination of heteroatom-doped carbon material with spinel oxides substantially improves the specific capacitance and cyclic stability. In this work, dopamine-derived nitrogen-doped carbon was coated on spinel phase MnCo2O4 nanospheres using simple solvothermal and calcination methods. Surface morphology and the crystalline structure of the prepared MnCo2O4@Nitrogen-doped carbon were confirmed by FESEM and X-ray diffraction. The electrochemical performance of MnCo2O4@Nitrogen-doped carbon electrode material was analyzed by cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy techniques. MnCo2O4@nitrogen-doped carbon exhibits the highest specific capacitance of 1200 F/g compared to MnCo2O4 spheres are 726 F/g at 1 A/g and exhibits excellent cyclic stability (capacitance retention of 87% at 7 A/g after 3000 cycles). The enhanced performance of the composite might be benefitted from the synergistic effect between nitrogen-doped carbon on porous MnCo2O4 spheres. Furthermore, an asymmetric supercapacitor device was fabricated by using the optimized composition of MnCo2O4@NC-2 as a positive electrode and nitrogen, sulfur-doped reduced graphene oxide (NS-rGO) as a negative electrode, respectively. This asymmetric supercapacitor device achieves a maximum energy density of 61.0 Wh/kg at a power density of 2889 W/kg and possesses excellent capacitance retention of 95% after 5000 cycles at 7 A/g.

电化学溶出法尺寸可控合成铜基氧还原反应催化剂: 从纳米粒子到原子团簇和单原子

Size-controllable synthesis of non-noble metal particles ranging from nanometer to subnanometer and atomic level is of great significance for demonstrating the size effects of metallic catalysts towards oxygen reduction reaction (ORR) catalysis. Herein, we propose an electrochemical leaching strategy for the top-down synthesis of Cu nanoparticles (NPs), atomic clusters (ACs) and single atoms (SAs) on sulfur-doped reduced graphene oxide (SrGO). Within this strategy, Cu NPs (about 8 nm) were electrodeposited and subsequently controllably downsized to ACs (about 2 nm) and SAs (<1 nm) via a stripping voltammetry method by adjusting the termination potential. The effective control in the size of active Cu species allowed us to conveniently investigate the size effect of Cu on ORR in multiscale. Single-atom Cu exhibited good ORR performance with a half-wave potential of 0.86 V and an electron transfer number of 3.98, as well as a long-term stability, much superior to other larger Cu particles. Our findings open a new avenue for top-down synthesis of metal particles with desirable sizes, which will effectively benefit the future design of size-controlled ORR electrocatalysts.

Fabrication of Sulfur-Doped Reduced Graphene Oxide Modified Glassy Carbon Electrode (S@rGO/GCE) Based Acetaminophen Sensor

In the past few years, the design and fabrication of highly sensitive and selective electrochemical sensors have received enormous attention from electrochemists. Acetaminophen is an important drug that is used as an antipyretic and analgesic drug throughout the world. It is important to monitor the accurate amount of acetaminophen. Herein, we have prepared sulfur-doped reduced graphene oxide (S@rGO) using simple strategies. The morphological feature of the S@rGO was characterized by using scanning electron microscopy whereas phase purity and formation of S@rGO were authenticated by X-ray diffraction. Further, the glassy carbon electrode was modified using S@rGO as an electrode modifier and employed as an acetaminophen sensor (S@rGO/GCE). This modified sensor (S@rGO/GCE) demonstrates a reasonable detection limit of 0.07 µM and a sensitivity of 0.957 µA/µMcm2.

Synthesis of Pure Thiophene-Sulfur-Doped Graphene for an Oxygen Reduction Reaction with High Performance.

Various S-bonding configurations existing in sulfur-doped reduced graphene oxide (S-rGO) show different electronic structures and physiochemical properties. Thus, understanding the properties of unique S-bonding configurations requires the construction of S-rGO with only single configuration. Here, we synthesized S-rGO with a pure thiophene-sulfur configuration through a simple and low-cost hydrothermal method by simply controlling the oxidation degree of the graphene oxide (GO) precursor. Through the use of a GO precursor with a high content of C-O groups, pure doping of the thiophene-sulfur configuration in the rGO can be achieved. Further electrochemical characterization reveals an increased electrocatalytic activity of the pure thiophene-sulfur-doped S-rGO in the oxygen reduction reaction, indicating the important role of thiophene-sulfur. The present work deepens the understanding of the functions of doped nonmetal elements in carbon materials in electrocatalysis and helps in the design of high performance electrocatalysts.

Sulfur-doped reduced graphene oxide@chitosan composite for the selective and sensitive electrochemical detection of Hg2+ in fish muscle

In this study, a glassy carbon electrode was modified with sulfur-doped reduced graphene oxide (S-rGO) and then combined with chitosan (CTS) to produce an electrochemical sensor. There is a favorable interaction between Hg2+ and S-rGO, due to the strong affinity between sulfur and mercury. This effect was exploited for the selective and sensitive electrochemical determination of trace amounts of Hg2+ in fish muscle samples by differential pulse anodic stripping voltammetry (DPASV). The factors that can affect the sensitivity and precision of the modified electrode were investigated through the optimization of various parameters, such as S-rGO concentration, solution pH, deposition potential, accumulation potential, accumulation time, and supporting electrolytes. By introducing S-rGO to enrich and amplify the electrochemical signal, the sensing strategy allowed to detect a range from 0.125 to 6 μM Hg2+ with a detection limit of 1.6 nM. The sensor also showed excellent selectivity towards Hg2+ in the presence of interfering metal ions, such as Fe3+, Zn2+, Mg2+, Mn2+, As3+, Na+, Cd2+ and CO2+. The practical feasibility of the proposed sensor was assessed in fish muscle samples with satisfactory results compared with that of atomic fluorescence spectrometry. Moreover, this work demonstrated a simple and reliable method for improving the electrochemical performance of Hg2+ sensor, which paves the way for many promising potential applications in the field of environmental testing.

Enhanced Electrocatalytic Activity of Cobalt-Doped Ceria Embedded on Nitrogen, Sulfur-Doped Reduced Graphene Oxide as an Electrocatalyst for Oxygen Reduction Reaction

N, S-doped rGO was successfully synthesized and embedded Co-doped CeO2 via hydrothermal synthesis. The crystal structure, surface morphology and elemental composition of the prepared catalyst were studied by XRD, Raman spectra, SEM, TEM and XPS analyses. The synthesized electrocatalyst exhibits high onset and halfwave potential during the ORR. This result shows that a combination of N- and S-doped rGO and Co-doped CeO2 leads to a synergistic effect in catalyzing the ORR in alkaline media. Co–CeO2/N, S–rGO displays enhanced ORR performance compared to bare CeO2. The superior stability of the prepared catalyst implies its potential applications beyond fuel cells and metal–air batteries.

Synergistic effect of sulfur-doped reduced graphene oxide created via microwave-assisted synthesis for supercapacitor applications

Doping heteroatoms is an effective means of modifying the electrochemical properties of reduced graphene oxide (rGO). In this work, we propose the modification of rGO via microwave-assisted synthesis with different concentrations of sulfur at 140 °C for 30 min. Characterization using X-ray diffraction, Fourier-transform infrared, and Raman spectroscopy revealed successful doping with sulfur to alter the physical properties of rGO. The morphology of doped S-rGO samples exhibited wrinkling and folding of graphene sheets. Electrochemical evaluation revealed S-rGO with 0.25 M of sulfur (S-rGO-0.25) to have excellent electrochemical performance, with a specific capacitance of 237.6 F g−1 compared to the S-rGO with 0.15 M (S-rGO-0.15) and S-rGO with 0.50 M (S-rGO-0.50) with 98.2 and 61.7 F g−1 respectively. Furthermore, S-rGO-0.25 was validated as having an outstanding capacitance retention of 106% after 10,000 cycles signifying that it has promising potential as an electrode material for supercapacitor applications.

High performance alkaline battery-supercapacitor hybrid device based on diffusion driven double shelled CoSn(OH)6 nanocube@∝-Ni(OH)2 core-shell nanoflower

The design and fabrication of an alkaline battery-supercapacitor hybrid (BSH) device has been proposed here introducing a hierarchically orientated double hydroxide assembly of cobalt tin hydroxide@nickel hydroxide (CoSn(OH)6@∝-Ni(OH)2) as positive (CTH@NH) and nitrogen, sulfur-doped reduced graphene oxide (NSG) as negative electrode. CTH@NH was obtained through few step time-dependant processes. Double shelled CTH nanocube arrays were obtained by excess alkali etching of intermediate nanocubes that are resulted from fast co-precipitation process at earlier stage. Subsequent growth of ∝-Ni(OH)2 nanoflake upon double shelled CTH nanocube at high pressure and temperature resulted CTH@NH. Improvised core-shell nanodimensional architecture, reduced particle size, mesoporosity and ample surface charges encourage diffusion mediated charge storage with deep flow facility of electrolyte into inner core of electrode material and thus strengthening charge storage capability and capacity which assured significant specific capacity (Cm) of ∼ 1467.24 C g−1 (specific capacitance (Cs): ∼ 2445 F g−1) in the hybrid much higher than CTH (Cm ∼ 480.96 C g−1, Cs of ∼ 801.7 F g−1) at 1 A g−1. The [CTH@NH//NSG] assembled BSH acquired CASC of ∼ 151.5 F g−1 at 1 A g−1 current density with a long term cycling stability of ∼ 95% even after 8000 successive charge-discharge cycles. The concurrent battery performance of CTH@NH along with supercapacitive output of the NSG overcomes the deficiency of specific energy of supercapacitor by providing an excellent specific energy of ∼ 53.8 Wh Kg−1 at a specific power of ∼ 800 W Kg−1 and instigates the high-performance features in the as-fabricated BSH device.

High-flame retarding properties of polyacrylonitrile copolymer nanocomposites with synergistic effect of elemental sulfur-doped reduced graphene oxide and bio-derived catechol units

Polyacrylonitrile (PAN)-based flame retardants have been investigated as environmentally friendly high-flame retarding materials. High-flame retarding properties can be achieved in PAN copolymers via efficient thermal oxidative stabilization (TOS). In this study, PAN copolymers of dihydroxy styrene monomers with simple catechol units were synthesized as high-flame retardants using an efficient TOS process. To further improve the flame-retarding properties, PAN copolymer composites were prepared with graphene oxide (GO) and sulfur-doped reduced GO (SrGO). Differential scanning calorimetry (DSC) analysis revealed that the activation energy of the composites for cyclization reaction during TOS decreased with SrGO content. Micro combustion calorimeter revealed enhanced flame-retarding properties of P(AN-co-DHS3)-SrGO composites, resulting in a low heat release capacity (21 J/gK) and high limiting oxygen index (44.7%) (superior to Nomex®). The high-flame retarding properties could be attributed to the high char layer produced by efficient TOS of the copolymer with the catechol unit and radical scavenging effect of sulfur-functionalized SrGO. Therefore, the incorporation of SrGO into PAN copolymers with catechol units is a good alternative for developing environmentally friendly high-flame retardants.

Synthesis, characterization and electrocatalytic study of Pd supported on CeO2–N, S-rGO composite towards hydrogen and oxygen evolution reaction

The sustainable production of hydrogen and oxygen through the electrolysis of water requires the development of an efficient electrocatalyst. In this work, we report the electrocatalytic activity of Pd nanoparticles dispersed on CeO2/N, S-rGO (where N, S-rGO represents nitrogen and sulfur-doped reduced graphene oxide). The CeO2/N, S-rGO and Pd nanoparticles were synthesized by hydrothermal and chemical reduction methods, respectively. Electrochemical measurements towards hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) show a high electrocatalytic activity of the catalyst. Among the synthesized electrocatalysts Pd/CeO2/N, S-rGO exhibits lower overpotential (75 mV and 240 mV) at 10 mA/cm2 and lower Tafel slope value (44 mV/dec and 42 mV/dec) for HER and OER, respectively. The chronoamperometric and linear sweep voltammetry (LSV) of the electrocatalyst shows a negligible decrease in the current density for twelve hours and a minor change in the polarization curve after 10,000 cycles, respectively. The high electrocatalytic activity and superior stability of the synthesized electrocatalyst could be attributed to the synergetic effect between Pd nanoparticles and CeO2/N, S-rGO support. This work demonstrates a facile way to develop effective and stable electrocatalysts by exploiting the Pd/Metal oxide interface.

Surface Engineering of Three-Dimensional-like Hybrid AB2O4 (AB = Zn, Co, and Mn) Wrapped on Sulfur-Doped Reduced Graphene Oxide: Investigation of the Role of an Electrocatalyst for Clioquinol Detection

Clioquinol (CQ) is a mass-produced drug with broad-spectrum antifungal and antibacterial properties. This neurodegenerative medicine has attracted significant attention in the pharmaceutical field....

Rational design and preparation of copper vanadate anchored on sulfur doped reduced graphene oxide nanocomposite for electrochemical sensing of antiandrogen drug nilutamide using flexible electrodes

Copper vanadate nanoparticles (Cu2V2O7) are synthesized by using a simple hydrothermal method and later anchored with sulfur-doped reduced graphene oxide (S-rGO) by using ultrasonication to form a hybrid nanocomposite. The synthesized composite underwent characterizations like X-ray diffraction analysis (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), Dynamic ray scattering-Ultra violet–visible spectroscopy (DRS-UV–visible) and X-ray photoelectron spectroscopically revealed the triclinic pattern of the P 1̅ space group of α-Cu2V2O7 and the reduced oxygen deficiency state of metal centers (Cu+ or V4+) resulting with oxides of mixed-valence oxidative states and forming of Cu-O bond. Morphological analysis was carried out by using transmission electron microscopy (TEM) and Field emission scanning electron microscopy (FE-SEM) with elemental mapping and EDX analysis. Furthermore, a novel electrochemical sensor is prepared by using the hybrid sCu2V2O7/S-rGO nanocomposite on to a disposable screen-printed carbon paste electrode (SPCE) for electrochemical sensing of antiandrogen drug nilutamide (NLT). This report reveals excellent activity in determining NLT with a low detection limit of 0.00459 nM for the linear range of 0.001–15 μM with high sensitivity of 26.2605 µA µM−1 cm−2. Further, electrode performance showed appreciable performance in real-time monitoring of biological samples like human blood serum, urine samples.

Synergetic effect between MoS2 and N, S- doped reduced graphene oxide supported palladium nanoparticles for hydrogen evolution reaction

An active, stable, and relatively low-cost electrocatalyst is crucial in the sustainable production of hydrogen through water electrolysis. In this work, the electrocatalytic activity of Pd supported on MoS2 and nitrogen, sulfur-doped reduced graphene oxide (Pd/MoS2/N,S-rGO) was investigated by two-step hydrothermal method followed by chemical reduction of Pd using sodium borohydride (NaBH4). The Structural and morphological structure of the sample was studied by using X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscope (HRTEM) techniques. The electrochemical hydrogen evolution (HER) performance of the electrocatalyst was studied by using Linear Sweep Voltammetry (LSV), Electrochemical Impedance Spectroscopy (EIS), and Chronoamperometry (CA). The result shows a structural transformation in the MoS2 phase after the incorporation of Pd nanoparticles. The synthesized (Pd/MoS2/N,S-rGO) electrocatalyst shows a significantly lower overpotential of −42 mV vs. RHE at 10 mA/cm2 and Tafel slope value of 38 mV.dec−1. This study demonstrated with low palladium loading, the high activity of the electrocatalyst could have resulted from the cumulative effect of 1T MoS2, sulfur vacancy formation, and higher surface area of N,S-rGO.