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Hierarchical MoSe2-CoSe2 nanotubes anchored on graphene nanosheets (G/MS-CS NTs) are in-situ converted from the CoMoO4 nanowires (NWs) and graphene oxide hybrid precursor via a facile hydrothermal method. As an electrocatalyst, G/MS-CS NTs show highly efficient and stable performance for hydrogen evolution reaction (HER) in alkaline medium. G/MS-CS NTs demonstrate superior HER performance with a very low onset overpotential of 109 mV vs. RHE, a low overpotential of 198 mV vs. RHE at −10 mA cm−2, a small Tafel slope of 79 mV dec−1, a large current density of 53.7 mA cm−2 at −300 mV vs. RHE, and excellent long-term cycling stability. The outstanding HER activity of G/MS-CS NTs is attributed to its unique hierarchical structure with MS-CS NTs anchored on two-dimensional graphene nanosheets. The MS-CS NTs are well-constructed by few-layered MoSe2 nanosheets and CoSe2 nanoparticles with highly homogenous distribution, which can not only effectively suppress the aggregation of MoSe2 nanosheets, but also generate more active sites or edges to enhance the electrocatalytic activity. In addition, the highly conductive graphene matrix can efficiently promote the electron transfer from the electrode to the active sites on MS-CS NTs during electrocatalytic process, further improving the HER performance.

A novel porous electrocatalyst of reduced graphene oxide (RGO)-wrapped NiSe2-Ni0.85Se hollow microspheres (RNHM) has been synthesized via one-pot hydrothermal process, which is facile, cheap and easy to realize scalable manufacture. Compared to bare NiSe2, Ni0.85Se and NiSe2-Ni0.85Se hollow microspheres (NHM), RNHM shows outstanding hydrogen evolution properties with a low Tafel slope value of 31.3 mV dec−1, a low onset potential of −175 mV (vs RHE), and a high cathode current density of 37 mA cm−2 (at ∼ −240 mV vs RHE). More importantly, it shows excellent HER stability after 2000 CV cycles. That superior performs of RNHM can be attributed to the well-designed hollow microsphere architecture with rich porosity and high specific surface area, which provides abundant active sites for HER. In addition, the two-dimensional graphene nanosheets can not only act as a highly conductive matrix facilitating the charge transfer during the process of HER, but also work as a flexible skeleton guaranteeing excellent structural stability. This study provides a novel and rational architecture design strategy of Pt-free catalysts with superior performances and outstanding stability for hydrogen evolution reaction.

The hierarchical porous nanoarchitecture of WSe2/reduced graphene oxide (WSe2/RGO) hybrid, constructed by few-layered WSe2 nanosheets in-situ grown on RGO nanosheets, has been synthesized through a facile one-pot solvothermal method. The WSe2/RGO hybrid can be used as an efficient anode for lithium-ion (Li-ion) batteries and exhibits much better electrochemical performance than that of bare WSe2: the WSe2/RGO hybrid delivers a high initial discharge capacity of 744 mA h g−1 at 0.2C and it remains 528 mA h g−1 after 80 cycles, while the bare WSe2 has a lower discharge capacity of 549 mA h g−1 at 0.2C and it remains only 98 mA h g−1 after 80 cycles; the WSe2/RGO hybrid also demonstrates remarkably rate capability under different current rates from 0.2 to 8C. Those outstanding electrochemical performances of WSe2/RGO hybrid can be assigned to its unique nanoarchitecture: the RGO nanosheets with high conductivity work as the skeleton of WSe2/RGO anode facilitating the electron transfer; the RGO nanosheets can effectively prevent WSe2 from the aggregation and promote the in-situ growth of WSe2 layers on graphene, guaranteeing the formation of hierarchical porous nanoarchitecture with abundant electrochemically active sites, which can allow for efficient ionic diffusion and easy electrolyte infiltration. This study presents a rational-designed structure and facile strategy to fabricate transition metal dichalcogenides (TMDs)/graphene hybrid as promising anodes for lithium-ion batteries.

For the first time, self-assembled graphene/Ni0.85Se-SnO2 (GNS) microspheres, which are constructed by homogenously distribution of Ni0.85Se-SnO2 nanoparticles wrapped by reduced graphene oxide nanosheets, have been synthesized by a facile and low-cost hydrothermal method. Due to the rationally designed nanoarchitecture and the high conductivity of SnO2 and graphene, the GNS electrocatalyst delivers excellent performance for hydrogen evolution reaction (HER): it exhibits a quite low Tafel slope of 35.8 mV dec−1 and a high cathode current density of 25 mA cm−2 at overpotential of 290 mV (vs RHE); it shows outstanding long-term stability even after 1000 CV cycles in acid solution. This study elucidates a rational construction design and a facile large-scale synthesis method of non-precious HER electrocatalysts with excellent HER performance to replace Pt-based electrocatalysts.

Metal-organic frameworks (MOFs) derived cobalt diselenide (MOF-CoSe2) constructed with CoSe2 nanoparticles anchored into nitrogen-doped (N-doped) graphitic carbon has been synthesized through in-situ selenization of Co-based MOFs. The obtained MOF-CoSe2 exhibits excellent hydrogen evolution reaction (HER) performance: it shows a small Tafel slope of 42 mV dec−1, a low onset potential of 150 mV; it delivers a high current density and excellent long-term stability. Such enhancement can be attributed to the unique N-doped MOFs derived architecture with high conductivity, which can not only provide abundant active reaction sites, but also ensure robust contact between the CoSe2 nanoparticles and N-doped carbon matrix, leading to outstanding electrocatalytic activity for HER. This study provides a route to prepared non-noble-metal catalyst with high efficiency and excellent electrocatalytic activity for HER.

Highly active, durable and inexpensive HER catalyst for electrochemical hydrogen evolution is a significant solution to cope with the energy crisis. Herein, self-assembled CoSe 2 nanocrystals embedded into carbon nanowires (CoSe 2 @CNWs) have been synthesized by a facile hydrothermal reaction and subsequent selenylation process. Compared to bare CoSe 2 NWs, the CoSe 2 @CNWs show outstanding performance of hydrogen evolution reaction (HER) with a small Tafel slope of 41.3 mV dec −1 and a low onset potential of ∼130 mV vs RHE. Moreover, the CoSe 2 @CNWs also demonstrate good long-term stability in acidic electrolyte with a high current retention of 94.1% after 1500 cycles. The excellent HER performance of CoSe 2 @CNWs is attributed to the unique architecture constructed by CoSe 2 nanocrystals embedded into highly conductive carbon nanowires, which guarantees rich active reaction sites and facilitates the charge transportation in HER process.

For the first time, a facile one-pot synthesis of chrysanthemum-like ReSe 2 microspheres (CRM), which are self-assembled by wrinkled few-layer ReSe 2 nanosheets with highly crystalline quality, is presented. Compared to ReS 2 , the ReSe 2 microspheres exhibit superior electrocatalytic activity for hydrogen evolution reaction (HER): the CRM catalyst delivers a small onset overpotential of 80 mV and the lowest Tafel slope of 67.5 mV/decade for all reported Re-based dichalcogenides; it also exhibits excellent stability. The unique chrysanthemum-like structure with rich wrinkled edges and abundant nanopores guarantees sufficient electrocatalytic active edge sites, resulting in excellent HER performance of ReSe 2 . Chrysanthemum-like ReSe 2 microsphere is a promising candidate for high-performance HER.

Tungsten selenide (WSe 2 ) has emerged as a promising electrocatalyst for hydrogen evolution reaction (HER), and its HER performance strongly depends on its conductivity and exposed edge sites. Herein, a RGO/WSe 2 hybrid network constructed with few-layered WSe 2 nanoflowers anchored on graphene nanosheets has been synthesized through a facile one-pot solvothermal method. Compared with bare WSe 2 nanoflowers with relatively poor HER performance, the RGO/WSe 2 hybrid demonstrates a highly effective and stable electrocatalytic performance: it delivers a small Tafel slope of 57.6 mV dec −1 , a remarkably low onset potential of ∼ 150 mV, a high current density of 38.43 mA cm −2 at 300 mV vs RHE and excellent long-term stability. The superior HER performance of RGO/WSe 2 hybrid is attributed to the unique WSe 2 -anchored-on-graphene structure, which ensures the robust contact between the few-layered WSe 2 -nanoflowers catalyst and the highly conductive graphene matrix, leading to enhance the charge transfer kinetics between the catalytic edge sites and the graphene nanosheets. Therefore, the RGO/WSe 2 hybrid is promising as high-performance catalysts for hydrogen evolution applications.

In this report, three-dimensional hierarchically structured aerogels constructed with ultrathin layered MoS 2 /graphene nanosheets (3DMG) synthesized with a facile one-pot hydrothermal method, are employed as anodes for lithium-ion batteries (LIBs) without conductive additives, polymer binders or metal current-collectors. Due to the integration of three-dimensional porous structure and ultrathin layered MoS 2 /graphene, the 3DMG aerogel anode exhibits a high reversible capacity and an excellent high-rate capability. In addition, the 3DMG aerogels anode maintains a capacity of ∼870 mAh g −1 at 1 A g −1 after 200 cycles, demonstrating superior long-cycle performances of 3DMG aerogels at a high current density. The reported 3DMG aerogels have promising application potentials in highly-efficient lightweight LIBs.

Herein, pomegranate-like Silicon/Nitrogen-doped graphene microspheres (PSNGM) constructed by individual Si nanoparticle core wrapped by flexible nitrogen-doped reduced graphene oxide nanosheets (NG) have been synthesized through a facile and industrially large-scale spray drying approach. The PSNGM anode delivers excellent electrochemical performance: the reversible specific capacity at 100 mA g −1 remains as large as 1141.6 mAh g −1 after 150 cycles, with a high capacity retention of 96.1% from 2nd to 150th cycle; the capacity at 100 mA g −1 can recover back to ∼1340 mAh g −1 even after suffering a high current density of 5000 mA g −1 . The excellent performance is attributed to the unique pomegranate-like structure, nanoparticlization of Si and nitrogen doping of graphene: the pomegranate-like skeleton forms a highly conductive network, in which each Si nanoparticle is homogenously wrapped by flexible and conductive N-doped graphene nanosheets; flexible porous pomegranate-like structure can effectively accommodate the large volume variation during cycling; the N-doped graphene matrix guarantees its high conductivity for better electron and ion kinetics. The presented spray drying strategy is facile, low-cost and effective for large-scale industrial production of Si/graphene composite anode, and it can also be extended to fabricating other high-capacity electrode materials with low conductivities and large volume expansion.

For the first time, self-assembled CoS 2 nanoparticles wrapped by CoS 2 -quantum-dots anchored graphene nanosheets (CoS 2 NP@G-CoS 2 QD) are synthesized by a facile l -cysteine-assisted hydrothermal reaction. When the composite is used as anode in lithium-ion batteries (LIBs), it shows superior electrochemical performance: the reversible specific capacity is as large as 1048 mAh g −1 ; the 300 th -cycle capacity still maintains 831 mAh g −1 even at 1 A g −1 ; the rate capacity remains 411 mAh g −1 even at 10 A g −1 , which is the highest value ever reported at such high current density for CoS 2 based materials. The excellent electrochemical performance is attributed to the unique structure with CoS 2 nanoparticles homogeneously wrapped by highly flexible and conductive few-layer graphene nanosheets adhering abundant CoS 2 quantum dots, which can effectively suppress the aggregation of CoS 2 nanoparticles, accommodate the volume change during the cycle processes and maintain high electrical conductivity of the electrode. The CoS 2 NP@G-CoS 2 QD composite is promising for superior-capability anode for LIBs and can be further extended to broad applications in supercapacitors, sensors, and catalysis.