Sucrose assisted hydrothermal synthesis of SnO2/graphene nanocomposites with improved lithium storage properties

Recent Advances on Black Phosphorus for Energy Storage, Catalysis, and Sensor Applications

As a new type of 2D semiconductor, black phosphorus (BP) possesses high charge-carrier mobility and theoretical capacity, thickness-dependent bandgap, and anisotropic structure, which has attracted tremendous attention since early 2014. To explore its full application in all aspects, studies based on BP nanostructures are swiftly expanding from the electronic field to energy storage and even biochemistry. The mechanism and application of BP in Li-/Na-ion battery anodes, oxygen evolution reaction/hydrogen evolution reaction catalysis, photocatalytic hydrogen production, and selective sensors are summarized. Based on the solid research on this topic, feasible improvements and constructive suggestions regarding these four fields are put forward.

Bridging Covalently Functionalized Black Phosphorus on Graphene for High-Performance Sodium-Ion Battery

Black phosphorus (BP) has recently aroused researchers' great interest as promising anode material for sodium-ion battery (SIB), owing to its high theoretical capacity (2596 mAh g^-1) and good electric conductivity (about 300 S m^-1). However, the large volume variation during electrochemical cycling makes it difficult to use for practical applications. Herein, the reversible performance of BP in SIB is significantly enhanced by bridging covalently functionalized BP on graphene. The enhanced interaction between the chemical functionalized BP and graphene improves the stability of BP during long-cycle running of SIB. The bridging reduces the surface energy and increases thickness of BP available for enlarging the channel between BP nanosheet and graphene. The enlarged channel stores more sodium ions for improving cycle performance. Significantly, two types of phosphorus-carbon bond are first detected during experimental analysis. Benefiting from the strategy, the BP-based SIB anode exhibits 1472 mAh g^-1 specific capacity at 0.1 A g^-1 in the 50th cycle and 650 mAh g^-1 at 1 A g^-1 after 200 cycles.

Confined Amorphous Red Phosphorus in MOF-Derived N-Doped Microporous Carbon as a Superior Anode for Sodium-Ion Battery

Red phosphorus (P) has attracted intense attention as promising anode material for high-energy density sodium-ion batteries (NIBs), owing to its high sodium storage theoretical capacity (2595 mAh g^-1 ). Nevertheless, natural insulating property and large volume variation of red P during cycling result in extremely low electrochemical activity, leading to poor electrochemical performance. Herein, the authors demonstrate a rational strategy to improve sodium storage performance of red P by confining nanosized amorphous red P into zeolitic imidazolate framework-8 (ZIF-8) -derived nitrogen-doped microporous carbon matrix (denoted as P@N-MPC). When used as anode for NIBs, the P@N-MPC composite displays a high reversible specific capacity of ≈600 mAh g^-1 at 0.15 A g^-1 and improved rate capacity (≈450 mAh g^-1 at 1 A g^-1 after 1000 cycles with an extremely low capacity fading rate of 0.02% per cycle). The superior sodium storage performance of the P@N-MPC is mainly attributed to the novel structure. The N-doped porous carbon with sub-1 nm micropore facilitates the rapid diffusion of organic electrolyte ions and improves the conductivity of the encapsulated red P. Furthermore, the porous carbon matrix can buffer the volume change of red P during repeat sodiation/desodiation process, keeping the structure intact after long cycle life.

A sandwich-type electrochemical immunosensor based on the biotin- streptavidin-biotin structure for detection of human immunoglobulin G

A sandwich-type immunosensor is designed and fabricated to detect the human immunoglobulin G (HIgG) using polyaniline and tin dioxide functionalized graphene (GS-SnO2-PAN) as the platform and biotin-functionalized amination magnetic nanoparticles composite (B-Fe3O4@APTES) as the label. GS-SnO2-PAN is used as the sensing agent to capture the primary anti-HIgG (Ab1) and SnO2 reduces the stack of GS. The B-Fe3O4@APTES with a large surface area and excellent biocompatibility captures second antibody (Ab2) efficiently based on the highly selective recognition of streptavidin to biotinylated antibody. The B-Fe3O4@APTES has better electro-catalytic activity in the reduction of hydrogen peroxide (H2O2) and the "biotin-streptavidin-biotin" (B-SA-B) strategy leads to signal amplification. Under optimal conditions, the immunosensor has a wide sensitivity range from 1 pg/L to 10 ng/L and low detection limit of 0.33 pg/L (S/N = 3) for HIgG. The immunosensor has high sensitivity, fast assay rate, as well as good reproducibility, specificity, and stability especially in the quantitative detection of biomolecules in serum samples.

Three dimensional metal oxides–graphene composites and their applications in lithium ion batteries

The review focuses on the effects of morphology, composition and interaction of 3d metal oxide–graphene composites on the performances of libs.

Solution-processable design strategy for a Li2FeSiO4@C/Fe nanocomposite as a cathode material for high power lithium-ion batteries

Li₂FeSiO₄@C/Fe nanocomposites have been synthesized by solution-processable approaches, which exhibit a superior rate performance as a cathode material for lithium-ion batteries.