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Abstract Despite many efforts devoted to explore novel electrode materials for lithium ion hybrid supercapacitors, the obtainable long-life cycling of existing anode materials are still inadequate for promising applications. This report demonstrates a new nanocomposite with TiNb 2 O 7 network nanostructure in situ anchored onto the holey graphene, which is designed as anode material for lithium ion hybrid supercapacitors. Impressively, electrochemical analyses show that the good rate performance (capacity retention of 73.5% from 0.05 to 5 A g−1) and long cycle life up to 1000 cycles at 1 A g−1 (a capacity retention of 91.5%) are attained. Furthermore, the lithium ion hybrid supercapacitor device consisting of this nanocomposite and activated carbon exhibits excellent cycling stability (90.2% of initial capacity after 3000 cycles), high energy density of 86.3 W h kg−1 (at 237.7 W kg−1) and high power density of 3.88 kW kg−1 (at 28.7 W h kg−1). This study ascribes the unprecedented performance to the high conductive holey graphene with abundant mesopores, the uniformly distributed TiNb 2 O 7 network nanostructure and the synergetic effect between them. Based on these findings, the presented nanocomposite has great potential in high performance lithium ion hybrid supercapacitors. Graphical abstract Image 1 Highlights • A novel composite of TiNb 2 O 7 network nanostructure and holey graphene was fabricated. • The long-term life with 91.5% capacity retention after 1000 cycles was obtained. • The Li-HSC device exhibits high energy density and excellent cycling stability. [ABSTRACT FROM AUTHOR]

The utility of TiO 2 as an anode for lithium-ion storage is hindered by low conductivity and sluggish ionic diffusion. Here, the 2D N-doped carbon-wrapped TiO 2 (TiO 2 @NC) composite with a thickness of 5.5 nm derived from the 2D metal-organic framework was designed. This composite consisting of TiO 2 nanoparticles embedded in ultrathin N-doping carbon was used to address the rate and cyclability of Li-ion batteries. The 2D nanosheet morphology obtained from Ti 8 O 8 (OH) 4 (BDC-NH 2) 6 （NH 2 -MIL-125 (Ti)）effectively increases the specific surface area and shortens the electron/ion transport pathway. The chemical bond of Ti-C-O between TiO 2 nanocrystals and N-doping carbon further improve conductivity. Due to its unique structure, the produced TiO 2 @NC composite shows excellent cyclability with a reversible capacity of 110 mAh g–1 after 2000 cycles at 0.5 A g–1. Furthermore, the 2D TiO 2 @NC exhibits outstanding rate performance (71 mAh g–1 at 5 A g–1) compared to bulk TiO 2 @NC. This general concept can be extended to the development of metal oxide materials based on insertion mechanisms, such as Nb 2 O 5. • The 2D TiO 2 @N-doping carbon composite with a thickness of 5.5 nm is prepared. • Solvent-dependent variation of morphology NH 2 -MIL-125(Ti) MOF is investigated. • The TiO 2 nanocrystals embedded in ultrathin N-doping carbon nanosheets via chemical bonding. • The TiO 2 @N-doping carbon composite shows excellent lithium-ion storage performances. [ABSTRACT FROM AUTHOR]

MoS 2 is cognized as a promising Lithium-ion battery (LIB) anode material. However, its unsatisfied conductivity and instability hinder its rate performance and cycling stability. Herein, we design a simple strategy to prepare MoS 2 /N-doped carbon (denoted MoS 2 @N–C) nanotubes as anode materials for LIBs. The unique hybrid architecture composed of MoS 2 nanosheets and N–C nanotube achieves excellent electrochemical performance with an exceptional rate capacity (1338 mAh g−1 at 0.2 A g−1) and exceptionally stable cyclic performance (1411 mAh g−1 after 1000 cycles at 1.0 A g−1). The unique hybrid hollow architecture of MoS 2 @N–C provides a new pathway to designing hollow structures for high performance LIBs. [Display omitted] • MoS 2 @N–C nanotube was successfully developed by a facile template method. • The strong bonding between MoS 2 and N–C improves the structural stability. • MoS 2 @N–C nanotube exhibits an excellent cycle performance and rate capability. • The method can be extended to many high-performance MoS 2 composite anodes. [ABSTRACT FROM AUTHOR]

• Ni(Co)MoO 4 hybrid electrode with a mixed structure was synthesized on nickel foam. • The hybrid electrode exhibits a remarkable cycling performance due to the mixed morphology. • The asymmetric supercapacitor shows a high energy density of 55.71 Wh kg−1 at the power density of 375 W kg−1. [Display omitted] In this work, the Ni(Co)MoO 4 (NMO-Co) hybrid materials with nanoneedle and nanosheet structure were prepared on nickel foam (NF) by the hydrothermal method for high-stability supercapacitors. The effect of Co presence on the structure and electrochemical properties of NMO-Co was investigated. As the molar of Cobalt increased, more nanoneedles grew on the surface of NiMoO 4 /NF. The combination of the Ni-doped CoMoO 4 nanoneedles and Co-doped NiMoO 4 nanosheets was irregularly arranged on the surface of NF, which emerged an improvement of the cycling performance. When the molar ratio of Co: Ni: Mo was 0.5: 1: 1, the capacitance retention of the hybrid electrode was 80.1% after 10,000 cycles at 10 A g−1, while the pure NiMoO 4 electrode was 53.1%. Moreover, an asymmetric supercapacitor device displayed high energy density and power density. The maximum energy density and power density could reach 55.71 Wh kg−1 and 14,999 W kg−1, respectively. The hybrid electrode's good electrochemical performance is due to the combination of mutual doping of Ni and Co with a mixed morphology. [ABSTRACT FROM AUTHOR]

Ultrafine CuS nanoparticles anchored on nitrogen-sulfur co-doped graphene nanosheets are synthesized by a simple-green solvothermal method, the composite has excellent electrochemical performance for CO 2 reduction. [Display omitted] • The CuS/N, S-rGO was synthesized via a facile and environmentally friendly method. • The co-doping of N and S on graphene can promote the activation and conversion of CO 2. • CuS/N, S-rGO exhibits outstanding formate selectivity for CO 2 RR. Electrochemical conversion of CO 2 into hydrocarbons can effectively alleviate the energy crisis and promote carbon cycle. Herein, we report that small-size CuS nanoparticles are confined in nitrogen and sulfur co-doped reduced graphene oxide (CuS/N,S-rGO) for electrochemically reducing CO 2 to formate. Specifically, the CuS/N,S-rGO electrode achieves maximum Faradaic efficiency of 82% for formate formation at −0.63 V versus the reversible hydrogen electrode (RHE). Moreover, this catalyst exhibits a stable performance during 20 h-electrolysis. Experiments demonstrate that the doping of nitrogen and sulfur can create an abundance of active sites on the graphene nanosheets to accelerate the CO 2 reduction reaction (CO 2 RR). The CuS/N,S-rGO electrode exhibits excellent performance for CO 2 RR is attributed to the synergistic effect between N,S-rGO and CuS, and graphene can improve stability of composite. This work provides an efficient electrocatalyst for CO 2 RR and offers a facile and environmental friendly approach to synthesize small-size Cu-based composites. [ABSTRACT FROM AUTHOR]

Passive inhalation of chloramphenicol (CAP) and untimely intake of riboflavin (RF) can cause damage to physical function. The quantitative detection of these two substances is conducive to monitoring human health, while a method for detecting these two substances at the same time has not been reported. In this paper, an efficient sensor for simultaneous detection of RF and CAP by culturing molybdenum disulfide nanosheets on nitrogen-doped seaweed-derived porous carbon (N-PC@MoS 2) has been prepared. The introduction of N-PC improved the conductivity of the composite and reduced the agglomeration of the MoS 2 nanosheets to guarantee the exposure of more catalytic sites. Consequently, the composite material represented improved electrochemical performance and the ideal simultaneous detection of CAP and RF was achieved in the linear range of 10 ~ 500 μM. In addition, the sensor has been proven to have sufficient stability and anti-interference, which makes it potential in practical applications. This work also noticed the reaction sites and activities of RF and CAP prediction through orbit-weighted dual descriptor, providing a direction for an in-depth understanding of the reaction mechanism of target molecules at the electrode interface. [Display omitted] [ABSTRACT FROM AUTHOR]