•Pillar[5]arene supramolecule is used for hydrothermal synthesis of MoS2/rGO hybrid.•MoS2 sheets with more active edge sites are well anchored on rGO surface.•The hybrid exhibits high electrocatalytic activity for HER with a low Tafel slope.•The hybrid shows high potential as a promising electrocatalyst for H2 production.MoS2/reduced graphene oxide (MoS2/rGO-NP) hybrid is fabricated through one-pot hydrothermal route with mediation of a water-soluble N-methylimidazole pillar[5]arene supramolecule. MoS2 sheets with more exposed active edge sites are well dispersed on the rGO surface. Electrochemical measurements demonstrate that MoS2/rGO-NP hybrid exhibits outstanding electrocatalytic performance for hydrogen evolution reaction with a low Tafel slope of 44.5 mV/dec and significantly enhanced kinetics. Thus, the MoS2/rGO-NP hybrid holds high potential as a promising earth-abundant electrocatalyst for the cost-effective production of hydrogen.

An SnCoS4/graphene composite is synthesized via a one-step hydrothermal route. Characterizations reveal that such composite consists of SnCoS4 hybrid nanocrystals with small and uniform sizes, which are well dispersed on graphene. The electrochemical lithium storage measurements demonstrate that the SnCoS4/graphene composite exhibits a high reversible capacity of 1396 mA h g−1 at 100 mA g−1 and enhanced rate capability of 1145 mA h g−1 at 1000 mA g−1. In particular, a reversible capacity of 940 mA h g−1 can be retained after 2000 cycles at a high current density of 2000 mA g−1, indicating its excellent cyclic stability. The SnCoS4/graphene composite prepared in this work is promising as the host electrode material for high-performance lithium ion batteries.

A facile one-pot hydrothermal route with the mediation of ionic liquid (IL, [BMIM]BF4) is presented to synthesize MoS2/nitrogen-doped graphene (MoS2/NG-IL) composites. It is found that as-prepared MoS2/NG-IL composites exhibit that the de-layered MoS2 sheets with more exposed edge sites and defects are well anchored on the N-doped graphene. Due to the synergism between de-layered MoS2 and N-doped graphene, MoS2/NG-IL composites exhibit better electrochemical performances for hydrogen evolution reaction (HER) and reversible lithium storage in comparison with MoS2. Especially, when 1.0 mL of IL is added in hydrothermal solution, the obtained MoS2/NG-IL10 displays very high electrocatalytic activity for HER with a low onset overpotential of 80 mV and a small Tafel slope of 48.0 mV/dec in 0.5 M H2SO4. As anode of lithium ion battery, MoS2/NG-IL10 delivers a reversible capacity as high as 1169 mAh g−1 at 100 mA g−1 and enhanced rate capability of 782 mAh g−1 at 1000 mA g−1. After 800 cycles, a reversible capacity of about 800 mAh g−1 at 500 mA g−1 can be retained, indicating its excellent cyclic stability.

•Molybdenum disulfide/graphene composite is prepared by an ionic liquid-mediated hydrothermal route.•The composites display de-layered MoS2 sheets anchored on the graphene surface.•Molybdenum disulfide/graphene catalyst exhibit excellent electrocatalytic performance for HER.The ionic liquid (IL, [BMIM]BF4) is employed to mediate the preparation of molybdenum disulfide/graphene composites by hydrothermal route in the presence of graphene oxide sheets. The effects of ionic liquid on the microstructure and hydrogen evolution reaction performances of molybdenum disulfide/graphene are investigated. The molybdenum disulfide/graphene composite (MoS2/G-IL10) prepared with 1.0 mL of ionic liquid displays numerous de-layered molybdenum disulfide sheets with short slab length and discontinuous crystal fringes on the surface of grapheme. Due to the rich exposed edge sites, as well as the synergetic effect of de-layered molybdenum disulfide and graphene sheets, the MoS2/graphene composite prepared by IL-mediated hydrothermal method shows excellent electrocatalytic performance for hydrogen evolution reaction with a small Tafel slope of 52 mV/dec in acidic medium.MoS2/graphene (MoS2/G-IL) composites were prepared by hydrothermal route with mediation of ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate). The MoS2/G-IL composite displays de-layered MoS2 sheets aligned on the graphene and exhibits excellent electrocatalytic performances for hydrogen evolution reaction with a small Tafel slope of 52 mV/dec in acidic medium.

MoS2/reduced graphene oxide (MoS2/rGO) composites are fabricated through a facile supramolecule-mediated hydrothermal route. The effects of the supramolecule (pillar[5]arene) on the microstructure and electrochemical lithium storage performance of the MoS2/rGO composites are investigated. It is found that the MoS2/rGO composites display a wrinkled thin flaky appearance, in which there are a lot of irregular pores and apertures. Few-layer MoS2 sheets are well dispersed and anchored on the rGO surface. When evaluated as a host material for lithium storage, the MoS2/rGO composite exhibits a much higher specific capacity of 1050–1140 mA h g−1 with excellent cyclic performance and a significantly enhanced high-rate capability of 815–875 mA h g−1 at a current density of 1000 mA g−1 in comparison with the pristine MoS2. The improved performance can be ascribed to the robust composite structure and the better synergic effects between few-layer MoS2 and rGO sheets.

•l-Cysteine-assisted hydrothermal route for facile synthesis of NiS2/graphene composite.•NiS2 sphere-like nanoparticles are well dispersed on the corrugated graphene.•The composite delivers a reversible capacity as high as 1200 mAh g−1.•The NiS2/graphene exhibits the excellent cyclic stability and enhanced rate capability.NiS2/graphene composite is synthesized by a facile hydrothermal reaction between NiCl2 and l-cysteine in the presence of graphene oxide sheets. l-Cysteine serves as both the sulfur source for NiS2 and reductant for reduction of graphene oxide sheets. The reduced graphene oxides can be used as a platform for growth of NiS2 particles and restrain NiS2 from agglomerating during hydrothermal process. The results of characterizations show that the sphere-like NiS2 particles exhibit smaller sizes and are well dispersed on the surface of reduced graphene sheets. The electrochemical measurements demonstrate that the NiS2/graphene composite delivers a reversible capacity as high as 1200 mAh g−1 at a current density of 100 mA g−1 and enhanced high-rate capability of 740 mAh g−1 at a high current density of 1000 mA g−1. After 1000 cycles, the NiS2/graphene still preserves the reversible capacity about 810 mAh g−1 at a current density of 500 mA g−1, indicating its excellent cyclic stability.NiS2/graphene composite is synthesized by l-cysteine-assisted hydrothermal route in the presence of graphene oxide sheets. The sphere-like NiS2 particles are well dispersed on the surface of graphene sheets. The NiS2/graphene delivers a reversible capacity as high as 1200 mAh g−1 with the significantly enhanced rate capability. The capacity of 810 mAh g−1 at 500 mA g−1 can be preserved after 1000 cycles, indicating its excellent cyclic performance.

The unusual properties of graphene and graphene-like (GL-) layered metal dichalcogenides (LMDs, MoS2, WS2 and SnS2) have stimulated strong interest in GL-LMD/graphene composites. Heterostructures which are constructed by stacking GL-LMD and graphene together are expected to extend the usability of these 2D materials beyond graphene alone. This review will focus on recent progress in the synthesis and applications of GL-LMD/graphene composites in energy storage and conversion. The remarkable electrochemical properties of GL-LMD/graphene for reversible lithium storage are highlighted in particular. The applications of these composites in electrochemical and photochemical water splitting for hydrogen generation are also discussed.

•A facile method suitable for the large-scale production of 2D layered MoS2/graphene composite.•Good dispersion of 2D MoS2 with ∼6 layers on the surface of crumpled graphene nanosheets.•Excellent electrochemical properties of the MoS2/graphene composite as a reversible lithium storage host.Two dimensional (2D) layered MoS2/graphene and MoS2/XC-72 composites are synthesized by a facile aqueous reduction and heat treatment in N2, and characterized by XRD, SEM, TEM and HRTEM. It is found that the 2D MoS2 nanosheets with ∼6 layers are well dispersed on the crumpled graphene surface and the curved layered MoS2 with ∼10 layers coated on XC-72 carbon. Due to the outstanding properties of graphene and the synergistic interaction between 2D MoS2 and graphene nanosheets, the 2D MoS2/graphene composite exhibits a very high reversible capacity of 1060 mAh g−1 with excellent cycle stability and significantly enhanced rate capability compared with pristine MoS2 and the MoS2/XC-72 composite. The synthesis presented in this work can also be the blueprint for the facile production of the 2D MoS2/graphene composite on a relatively large scale.A facile method is presented for the synthesis of 2D layered MoS2/graphene composite that exhibits much higher reversible capacity with excellent cyclic performance and significantly enhanced rate capability compared to MoS2 and MoS2/XC-72 composite.

•FL-MoS2/GNS composites are prepared by a facile cationic surfactant–hydrothermal route.•Cationic surfactants show some ability to control layer number of FL-MoS2 in the composites.•FL-MoS2/GNS exhibits outstanding electrochemical properties as a reversible lithium storage host.Few-layer molybdenum disulfide/graphene (FL-MoS2/GNS) composites are fabricated by a facile hydrothermal route and a post-annealing with the assistance of various cationic surfactants (dodecyltrimethylammonium bromide, DTAB; octyltrimethylammonium bromide, OTAB; and tetrabutylammonium bromide, TBAB), which have different alkyl-chain lengths and stereo configurations. The effects of these cationic surfactants on the microstructures and electrochemical performances of the FL-MoS2/GNS for lithium storage are investigated. It is demonstrated the cationic surfactants show some ability to control the microstructure (layer number) of FL-MoS2 in composites. The electrochemical performances of FL-MoS2/GNS composites for lithium storage are greatly improved compared to the bare MoS2. Especially, FL-MoS2/GNS with ∼6 MoS2 layers prepared with the assistance of OTAB exhibits very high reversible capacity of ∼1200 mAh g−1 with excellent cycle stability and enhanced rate capability. Electrochemical impedance spectrum also confirms that the FL-MoS2/GNS composite electrodes exhibit much lower electron-transfer resistance than the MoS2. The remarkable electrochemical performances of FL-MoS2/GNS composites can be attributed to the synergistic interaction between FL-MoS2 and graphene and their quasi-3D architectures, which promote lithium diffusion, electron transfer and electrolyte access.

A facile and scalable process was developed for the synthesis of single-layer MoS2–graphene nanosheet (SL-MoS2–GNS) composites based on the concurrent reduction of (NH4)2MoS4 and graphene oxide sheets by hydrazine in the presence of cetyltrimethylammonium bromide (CTAB), followed by annealing in a N2 atmosphere. The morphology and microstructure of the composites were examined by X-ray diffraction, field emission scanning electron microscopy, high-resolution transmission electron microscopy and Raman spectroscopy. The formation process for the SL-MoS2–GNS composites was also investigated. The SL-MoS2–GNS composites delivered a large reversible capacity and good cycle stability as a Li-ion battery anode. In particular, the composites easily surpassed MoS2 in terms of rate performance and cycle stability at high current densities. Electrochemical impedance spectroscopy revealed that the GNS in the composite not only reduced the contact resistance in the electrode but also significantly facilitated the electron transfer in lithiation and delithiation reactions. The good electrochemical performance of the composites for reversible Li+ storage could be attributed to the synergy between the functions of SL-MoS2 and GNS.

The cobalt sulfides/graphene nanosheets (GNS) composite is prepared by a facile one-pot solvothermal route in the presence of graphene oxide sheets (GOS). XRD, SEM and TEM characterizations show that sphere-like cobalt sulfides particles with an average size of about 150 nm, which are complicated phases of CoS2, CoS and Co9S8, are highly dispersed on or wrapped in the creasy graphene. The selective nucleation and growth of cobalt sulfides particles on GOS make the particles more uniform in morphology and size. The as-fabricated cobalt sulfides/GNS composite exhibits very high electrochemical lithium storage reversible capacity of about 1018 mAh g−1. Moreover, the cobalt sulfides/GNS composite still remains reversible capacity of above 950 mAh g−1 after 50 cycles at a current density of 100 mA g−1 as well as at the different current densities from 100 to 1000 mA g−1, proving its excellent cycling durability and high-rate capability. The superior electrochemical performances of the composite may be attributed to the robust composite structure and superior conductivity, high charger mobility, large surface area and good flexibility of graphene.Graphical abstractThe cobalt sulfides/GNS composite was prepared by one-pot solvothermal route and exhibited high reversible capacity of 1018 mAh g−1 with excellent cycling stability and high-rate capability as anode material of Li-ion battery. The superior electrochemical performance may be attributed to robust composite architecture and multiple effects of graphene.Highlights► The cobalt sulfides/graphene composite is prepared by one-pot solvothermal route. ► The cobalt sulfides nanoparticles are highly dispersed on or wrapped in the creasy graphene. ► The composite exhibits high capacity with excellent cyclic stability and rate capability. ► We attribute the superior performances to robust composite and multiple effects of graphene.

MoS2/graphene composites were synthesized through the concurrent reducing of (NH4)2MoS4 and graphene oxide sheets with assistance of different cationic surfactants (DTAB, OTAB and TBAB) followed by heat treatment in a nitrogen atmosphere. The effects of the three cationic surfactants on the microstructures and electrochemical performances of the composites for reversible lithium storage were investigated. The MoS2 in the composites prepared with assistance of DTAB or OTAB displays single-/few-layer structure, while the layered MoS2 sheets with about 6–7 layers are observed in the composite prepared with assistance of TBAB. The former two composites exhibit greatly enhanced electrochemical performance for reversible Li+ storage. In particular, MoS2/graphene composite prepared with assistance of OTAB delivered a high reversible capacity of 1056 mA h g−1 with excellent cycle stability and good rate capability. The significant improvement in the electrochemical performances is attributed to the roubest composite structure and the synergistic interactions between graphene and single-/few-layer MoS2. This work also presented a facile process to prepare MoS2/graphene composites, in which the layer number of MoS2 sheets could be adjusted to a certain extent by using different cationic surfactants.

Here we develop a facile process for preparing few-layer SnS2/graphene (FL-SnS2/G) hybrid by solution-phase method employing l-cysteine as a complexing, sulfide source and reducing agent. The FL-SnS2/G hybrid is characterized by XRD, SEM and HRTEM. It is demonstrated that the few-layer SnS2 with defects or disorder structure supports on graphene surface. Electrochemical tests show the FL-SnS2/G hybrid exhibits an extraordinary capacity of up to 920 mAh g−1 with excellent cycling stability and high-rate capability. The significant improvement in the electrochemical performances is attributed to the robust composite structure and some synergistic interactions between few-layer SnS2 and graphene. Electrochemical impedance spectra confirm that the incorporation of graphene considerably improved the electric conductivity and electron rapid transfer of the FL-SnS2/G hybrid. Therefore, this new kind of FL-SnS2/G hybrid can be used as a promising anode material for lithium ion batteries.Graphical abstractThis few-layer SnS2/graphene hybrid synthesized by a facile solution-chemistry method displayed an impressively high Li+ storage capacity of 920 mAh g−1 which cycled well under a wide range of current densities.Highlights► We firstly reported a novel hybrid composed by graphene nanosheets and matched structural SnS2 nanosheets. ► This few-layer (FL) SnS2/graphene hybrid can be easily obtained by one-pot solution-chemical method. ► SnS2/graphene with many defect sites and few layered structure exhibited the extraordinarily high specific capacity and excellent cyclic stability.

Here we report a facile process to synthesize the novel nanocomposites comprised of single-layer MoS2, graphene and amorphous carbon (SL-MoS2/G@a-C) by a hydrothermal route employing sodium molybdate, sulfocarbamide, as-prepared graphene oxide and glucose as starting materials and then annealing in H2/N2 atmosphere at 800 °C. The samples were systematically investigated using X-ray diffraction, field emission scanning electron microscopy, and high-resolution transmission electron microscopy. It was demonstrated that the single-layer MoS2 and graphene in the composites dispersed highly uniformly in the amorphous carbon. The mechanism of the formation of SL-MoS2/G@a-C nanocomposites was investigated. It was found that the SL-MoS2/G@a-C nanocomposites exhibited very high reversible capacity with excellent cyclic stability and high-rate capability as anode materials of Li-ion batteries. Among three SL-MoS2/G@a-C samples, the SL-MoS2/G@a-C (1:1) nanocomposite delivered the largest reversible capacity (1116 mAh g−1) with negligible fading of the capacity after 250 cycles, and still retained a high specific capacity of 850 mAh g−1 and good cyclic stability at a high current density of 1000 mA g−1.

A facile process to synthesize graphene-like MoS2/amorphous carbon (a-C) composites was developed. MoS2/C composites were firstly prepared by hydrothermal method employing sodium molybdate, sulfocarbamide and glucose as starting materials. The graphene-like MoS2/a-C composites were obtained after annealing at 800 °C in H2/N2. The samples were characterized by XRD, SEM, EDS and HRTEM. It was confirmed that in the composites MoS2 has a structure of single-layer, which is named graphene-like nanostructure. The graphene-like MoS2 nanosheets were uniformly dispersed in amorphous carbon. The interlaminar distance of the adjacent graphene-like MoS2 nanosheets in the composites measured was ∼1.0 nm. The mechanism of the formation of the graphene-like MoS2/a-C composites was investigated. The graphene-like MoS2/a-C composites exhibited high capacity and excellent cyclic stability used as anode materials for Li-ion batteries. The composite prepared by adding 1.0 g of glucose in hydrothermal solution exhibited the highest reversible capacity (962 mAh g−1) and excellent cyclic stability. After 100 cycles, it still retained 912 mAh g−1. The significant improvements in the electrochemical properties of the graphene-like MoS2/a-C composites could be attributed to the graphene-like structure of the MoS2 nanosheets and the synergistic effects of graphene-like MoS2 and amorphous carbon.

A facile process was developed to synthesize MoS2/graphene nanosheet (GNS) composites by a one-step in situ solution-phase method. These MoS2/GNS composites therefore exhibit extraordinary capacity, i.e., up to 1300 mA h g−1, and excellent rate capability and cycling stability as an anode material for lithium ion batteries.

SnS2/SnO2 composites were prepared in a microwave-assisted reaction of a mixture solution of SnCl4 and l-cysteine and were characterised by XRD, TEM, SEM and EDX. The influence of the mole ratio of SnCl4 to l-cysteine (l-cys) on the sample was investigated. It was found that using a microwave method, SnS2/SnO2 composites were formed, and SnS2/SnO2 nanoparticles were obtained when the mole ratio of SnCl4 to l-cysteine was 1:2. With higher contents of l-cys, when the mole ratio of SnCl4 to l-cys was 1:4, the products were nanosheets instead of nanoparticles. Electrochemical tests demonstrated that the SnS2/SnO2 composites with layer structure exhibited high reversible capacities and good cycling performances when used as anode materials of Li-ion batteries. When the mole ratio of SnCl4 to l-cys was 1:6, the initial reversible capacity of products was 593 mAh/g, and the retention capacity that was maintained was over 88%. Besides, the retention capacity of products was still excellent at high current charge/discharge.

A facile process was developed to synthesize layered MoS2/graphene (MoS2/G) composites by an l-cysteine-assisted solution-phase method, in which sodium molybdate, as-prepared graphene oxide (GO), and l-cysteine were used as starting materials. As-prepared MoS2/G was then fabricated into layered MoS2/G composites after annealing in a H2/N2 atmosphere at 800 °C for 2 h. The samples were systematically investigated by X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and high-resolution transmission electron microscopy. Electrochemical performances were evaluated in two-electrode cells versus metallic lithium. It is demonstrated that the obtained MoS2/G composites show three-dimensional architecture and excellent electrochemical performances as anode materials for Li-ion batteries. The MoS2/G composite with a Mo:C molar ratio of 1:2 exhibits the highest specific capacity of ∼1100 mAh/g at a current of 100 mA/g, as well as excellent cycling stability and high-rate capability. The superior electrochemical performances of MoS2/G composites as Li-ion battery anodes are attributed to their robust composite structure and the synergistic effects between layered MoS2 and graphene.Keywords: ac impedance; anode material; l-cysteine-assisted; lithium ion battery; MoS2/graphene composites

MoS2/C nanocomposites were synthesized by a facile hydrothermal route employing sulfocarbamide, sodium molybdate and D-grouse as starting materials. XRD analysis showed that the MoS2 was a two-dimensional nanosheet crystal and C was retained as amorphous after their calcinations at 800 °C. TEM images showed that MoS2 was uniformly dispersed in the amorphous carbon. The MoS2/C composites exhibited high reversible capacity and excellent cyclic performance when used as Li-intercalation electrodes. The improvements in electrochemical performance are attributed to the incorporation of amorphous carbon, which can suppress the aggregation and pulverization of active materials, and keep the active materials electrically connected.

Few-layer molybdenum disulfide/reduced graphene oxide (MoS2/rGO) hybrids are fabricated through a facile hydrothermal route with mediation of a supramolecule (N-methylimidazole water-soluble pillar [5]arene, IMWP5). Effects of IMWP5 on the microstructure of MoS2/rGO hybrids are investigated. It is found that MoS2/rGO hybrids display a graphene-like morphology and few-layer MoS2 sheets are well dispersed on the surface of reduced graphene oxide (rGO). As host materials for electrochemical lithium storage, MoS2/rGO hybrid delivers a reversible specific capacity as high as 1289 mAh g−1 at a current density of 100 mA g−1 and exhibits enhanced rate capability of 963 mAh g−1 at a high current density of 1000 mA g−1. In particular, the reversible capacity of 996 mAh g−1 can be retained after 1100 cycles at current density of 1000 mA g−1, indicating its excellent cyclic stability. Such great electrochemical performance is ascribed to the robust heterostructure and synergetic effects between few-layer MoS2 and rGO.Few-layer MoS2/rGO hybrids are synthesized through a hydrothermal route with mediation of N-methylimidazole water-soluble pillar [5]arene and in the presence of commercial single layer graphene oxide sheets. The MoS2/rGO hybrid exhibits excellent electrochemical performance for reversible lithium storage. The reversible capacity of 996 mAh g−1 can be retained after 1100 cycles at current density of 1000 mA g−1, indicating its excellent cyclic stability.

Here we report a facile process to synthesize the novel nanocomposites comprised of single-layer MoS2, graphene and amorphous carbon (SL-MoS2/G@a-C) by a hydrothermal route employing sodium molybdate, sulfocarbamide, as-prepared graphene oxide and glucose as starting materials and then annealing in H2/N2 atmosphere at 800 °C. The samples were systematically investigated using X-ray diffraction, field emission scanning electron microscopy, and high-resolution transmission electron microscopy. It was demonstrated that the single-layer MoS2 and graphene in the composites dispersed highly uniformly in the amorphous carbon. The mechanism of the formation of SL-MoS2/G@a-C nanocomposites was investigated. It was found that the SL-MoS2/G@a-C nanocomposites exhibited very high reversible capacity with excellent cyclic stability and high-rate capability as anode materials of Li-ion batteries. Among three SL-MoS2/G@a-C samples, the SL-MoS2/G@a-C (1:1) nanocomposite delivered the largest reversible capacity (1116 mAh g−1) with negligible fading of the capacity after 250 cycles, and still retained a high specific capacity of 850 mAh g−1 and good cyclic stability at a high current density of 1000 mA g−1.

MoS2/reduced graphene oxide (MoS2/rGO) composites are fabricated through a facile supramolecule-mediated hydrothermal route. The effects of the supramolecule (pillar[5]arene) on the microstructure and electrochemical lithium storage performance of the MoS2/rGO composites are investigated. It is found that the MoS2/rGO composites display a wrinkled thin flaky appearance, in which there are a lot of irregular pores and apertures. Few-layer MoS2 sheets are well dispersed and anchored on the rGO surface. When evaluated as a host material for lithium storage, the MoS2/rGO composite exhibits a much higher specific capacity of 1050–1140 mA h g−1 with excellent cyclic performance and a significantly enhanced high-rate capability of 815–875 mA h g−1 at a current density of 1000 mA g−1 in comparison with the pristine MoS2. The improved performance can be ascribed to the robust composite structure and the better synergic effects between few-layer MoS2 and rGO sheets.

A facile process to synthesize graphene-like MoS2/amorphous carbon (a-C) composites was developed. MoS2/C composites were firstly prepared by hydrothermal method employing sodium molybdate, sulfocarbamide and glucose as starting materials. The graphene-like MoS2/a-C composites were obtained after annealing at 800 °C in H2/N2. The samples were characterized by XRD, SEM, EDS and HRTEM. It was confirmed that in the composites MoS2 has a structure of single-layer, which is named graphene-like nanostructure. The graphene-like MoS2 nanosheets were uniformly dispersed in amorphous carbon. The interlaminar distance of the adjacent graphene-like MoS2 nanosheets in the composites measured was ∼1.0 nm. The mechanism of the formation of the graphene-like MoS2/a-C composites was investigated. The graphene-like MoS2/a-C composites exhibited high capacity and excellent cyclic stability used as anode materials for Li-ion batteries. The composite prepared by adding 1.0 g of glucose in hydrothermal solution exhibited the highest reversible capacity (962 mAh g−1) and excellent cyclic stability. After 100 cycles, it still retained 912 mAh g−1. The significant improvements in the electrochemical properties of the graphene-like MoS2/a-C composites could be attributed to the graphene-like structure of the MoS2 nanosheets and the synergistic effects of graphene-like MoS2 and amorphous carbon.

A facile and scalable process was developed for the synthesis of single-layer MoS2–graphene nanosheet (SL-MoS2–GNS) composites based on the concurrent reduction of (NH4)2MoS4 and graphene oxide sheets by hydrazine in the presence of cetyltrimethylammonium bromide (CTAB), followed by annealing in a N2 atmosphere. The morphology and microstructure of the composites were examined by X-ray diffraction, field emission scanning electron microscopy, high-resolution transmission electron microscopy and Raman spectroscopy. The formation process for the SL-MoS2–GNS composites was also investigated. The SL-MoS2–GNS composites delivered a large reversible capacity and good cycle stability as a Li-ion battery anode. In particular, the composites easily surpassed MoS2 in terms of rate performance and cycle stability at high current densities. Electrochemical impedance spectroscopy revealed that the GNS in the composite not only reduced the contact resistance in the electrode but also significantly facilitated the electron transfer in lithiation and delithiation reactions. The good electrochemical performance of the composites for reversible Li+ storage could be attributed to the synergy between the functions of SL-MoS2 and GNS.

An SnCoS4/graphene composite is synthesized via a one-step hydrothermal route. Characterizations reveal that such composite consists of SnCoS4 hybrid nanocrystals with small and uniform sizes, which are well dispersed on graphene. The electrochemical lithium storage measurements demonstrate that the SnCoS4/graphene composite exhibits a high reversible capacity of 1396 mA h g−1 at 100 mA g−1 and enhanced rate capability of 1145 mA h g−1 at 1000 mA g−1. In particular, a reversible capacity of 940 mA h g−1 can be retained after 2000 cycles at a high current density of 2000 mA g−1, indicating its excellent cyclic stability. The SnCoS4/graphene composite prepared in this work is promising as the host electrode material for high-performance lithium ion batteries.

A facile process was developed to synthesize MoS2/graphene nanosheet (GNS) composites by a one-step in situ solution-phase method. These MoS2/GNS composites therefore exhibit extraordinary capacity, i.e., up to 1300 mA h g−1, and excellent rate capability and cycling stability as an anode material for lithium ion batteries.