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The iron and nitrogen co-doped porous carbon supported Au nanoparticle catalysts (Au/FeNPC) are synthesized via a facile pyrolysis method. The morphology, crystal structure, surface composition, and chemical state of the Au/FeNPC catalysts are investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The catalytic performances of the Au/FeNPC for BH4− oxidation reaction (BOR) are investigated by cyclic voltammetry (CV), chronoamperometry (CA), chronopotentiometry (CP), and linear voltammetric sweep (LSV). Among the as-prepared Au/FeNPC catalysts, Au/FeNPC-40 catalyst possesses the highest catalytic activity for BOR, and the BOR peak current density on the Au/FeNPC-40 electrode is up to 45.4 mA cm−2 with the high transferred electron number of 7.0.

Carbon-supported Au-doped N-C-coated CoFe alloy nanocomposite electrocatalysts (Au/CoFe@CN/C) are prepared and applied to BH4− electrooxidation. The physical and electrochemical properties of the catalysts are characterized and tested by X-ray diffraction, transmission electron microscopy, cyclic voltammetry, chronamperometry, chronopotentiometry, and rotating disk electrode voltammetry. The results show that Au(50)/CoFe@CN(50)/C has excellent catalytic performance for BH4− electrooxidation, high charge transfer number up to 6.4, and low precious metal content, making it a promising anode electrocatalyst of direct borohydride fuel cell.

Graphdiyne (GDY), a novel two-dimensional (2D) carbon material with sp- and sp2-hybridized carbon atoms, has earned a lot of attention in recent years. Owing to its low reduction potential and highly conjugated electronic structure, it can be used as a reducing agent and stabilizer for the electroless deposition of highly dispersed Au nanoparticles. In this paper, we observe that exfoliated GDY (eGDY), the exfoliation of bulk GDY into single- or few-layered GDY in aqueous solution, can be used as an excellent substrate for the electroless deposition of very small Au nanoparticles to form a Au/eGDY nanocomposite that exhibits higher catalytic performance for the reduction of 4-nitrophenol. The higher catalytic performance is considered to arise from the high specific surface area of eGDY and the electroless deposition of active metal catalysts with eGDY as the support. Our results inspired the present investigation into the use of eGDY for the development of highly efficient catalysts.

Carbon-supported Au modified N-doped carbon-coated FeMn alloy nanoparticle composites (Au/FeMn@CN/C) are prepared and used as electrocatalysts for BH4− electrooxidation. The surface morphology of the Au/FeMn@CN/C is observed using a transmission electron microscope and their composition is analyzed by X-ray diffraction. The results show that the prepared Au/FeMn@CN/C is a three-layer core–shell structure and the FeMn@CN nanosphere is coated with Au nanoparticles. The electrochemical performance of the prepared Au/FeMn@CN/C is studied by electrochemical tests, and the results show that Au(50)/FeMn@CN(50)/C shows the most excellent performance for direct BH4− electrooxidation which has more negative overpotential and an electrooxidation current density of up to 46.46 mA cm−2 with an electron-transfer number of 5.3.

Carbon supported Pd–Sn (Pd–Sn/C) nanoparticle electrocatalysts are prepared via a facile and environmentally friendly method and successfully applied in BH4− electrooxidation. Transmission electron microscopy results and X-ray diffraction results show that Pd–Sn nanocatalysts with a particle size of about 4 nm are uniformly distributed on the surface of a carbon black support without obvious agglomeration. Electrochemical results show that the catalytic activity of the Pd–Sn/C catalysts for BH4− electrooxidation is significantly higher than that of Pd/C. In particular, the Pd50Sn50/C catalyst has the highest electrocatalytic activity for BH4− electrooxidation among the four as-prepared catalysts. In addition, the BH4− electrooxidation reaction electron transfer number (n) of 3.9 was evaluated on the Pd50Sn50/C electrode.

A nitrogen-doped carbon-supported Au-modified NiFe alloy nanoparticle composite catalyst (Au/NiFe/N–C) has been prepared by a simple method and used as an electrocatalyst for the BH4− oxidation reaction (BOR). The physical and electrochemical properties of the as-prepared Au/NiFe/N–C catalyst have been tested by transmission electron microscopy, X-ray diffraction, cyclic voltammetry, chronoamperometry, chronopotentiometry, and rotating disk electrode voltammetry. The results showed that the catalytic activity of Au/NiFe/N–C for BOR was much higher than that of a carbon-supported Au nanocatalyst (Au/C); in particular, the Au(50)NiFe(50)/N–C catalyst demonstrated much higher catalytic activity with 2-fold higher peak current density than Au/C for BOR.

Pd/C and Pd-Co/C nanocatalysts are prepared via a simple and environmentally friendly method and are used as anodic catalyst for direct borohydride–hydrogen peroxide fuel cells. X-ray diffraction and transmission electron microscopy results indicate that Pd and Pd-Co nanoparticles adhere on carbon with the mean diameter of about 4 nm. The cyclic voltammetry, chronoamperometry, chronopotentiometry, and rotating disc electrode voltammetry results show that the electrocatalytic activity of Pd-Co/C is higher than that of Pd/C, especially Pd67Co33/C which shows the highest electrocatalytic activity for BH4− electro-oxidation with the electron-transfer number of 4.9 related to BH4− electro-oxidation reaction. The single direct borohydride–hydrogen peroxide fuel cell with Pd67Co33/C anode obtains the maximum power density as high as 66.84 mW cm−2 at 25 °C.

Li-rich material 0.4Li2MnO3·0.6LiNi1/3Co1/3Mn1/3O2 with a layered/spinel heterostructure is synthesized by a simple strategy. On the basis of structure and morphology analyses, it is revealed that the as-prepared Li-rich material possesses both porous micronano structure and integral layered-spinel heterostructure. Moreover, the obtained layered-spinel cathode material possesses prominent electrochemical characteristics, especially its rate capability. The initial discharge capacity of the as-prepared material is 269 mAh g–1 with a high Coulombic efficiency of 90.3%. The material delivers discharge capacities of 239 mAh g–1 at 0.5C, 195 mAh g–1 at 5C, and 175.8 mAh g–1 even at 10C. Also, the capacity retention of the cell is still as high as 80% at high current density (5C) after 200 cycles. The addition of spinel can inhibit the collapse of the material structure and voltage fading upon cycling. The 3D spinel Li4Mn5O12 phase in the Li-rich compound could provide a fast Li-ion diffusion pathway and a poro...

Mesoporous Ni-P@NiCo2O4 composite materials have been fabricated via a facile strategy including solvothermal synthesis of Ni-P and subsequent chemical deposition of NiCo2O4. Due to the synergistic effect between Ni-P and NiCo2O4, the Ni-P@NiCo2O4 composite materials exhibit an enhanced performance (1240 F g−1 at 1 A g−1, 668 F g−1 at 16 A g−1) compared with the bare Ni-P materials (717 F g−1 at 1 A g−1, 106 F g−1 at 16 A g−1) and NiCo2O4 materials (741 F g−1 at 1 A g−1, 457 F g−1 at 16 A g−1). Furthermore, the AC//Ni-P@NiCo2O4 asymmetric capacitor exhibits superior energy/power densities (13.3 Wh kg−1/5.7 kW kg−1) and cycling behavior (78.3% retention after 10,000 cycles at 4 A g−1) than the AC//Ni-P asymmetric capacitor (7.4 Wh kg−1/5.7 kW kg−1, 63.4% retention after 10,000 cycles at 4 A g−1) and AC//NiCo2O4 asymmetric capacitor (10.4 Wh kg−1/5.6 kW kg−1, 32.4% retention after 10,000 cycles at 4 A g−1). The high performance makes the mesoporous Ni-P@NiCo2O4 composite materials promising electrode materials for supercapacitors.

In this study, preparation of nitrogen- and oxygen-codoped porous carbonaceous foam and its application as metal nanoparticles catalysts support for direct methanol fuel cell (DMFC) were presented. Tadpole-like single chain polymer nanoparticles stabilized water-in-acrylonitrile/divinyl benezene high internal phase emulsion (HIPE) was firstly prepared, and the formed HIPE was then converted into polymer of high internal phase emulsion (polyHIPE) through a radical polymerization reaction. Subsequently, the formed acrylonitrile/divinyl benezene based polyHIPE was hypercrosslinked via FeCl3 catalyzed Friedel-Crafts reaction in 1,2-dichloroethane. After pyrolysis of the hypercrosslinked polyHIPE at elevated temperature under N2 atmosphere, nitrogen- and oxygen-codoped porous carbonaceous foam exhibiting highly interconnected macroporous cells and a micro-/mesoporous carbon skeleton (carboHIPE) was obtained. The resultant carboHIPE was further applied as the support for Pt and Ru bimetal nanoparticles. Well-dispersed PtRu bimetal nanoparticles with a smaller size were perfectly dispersed on the surface of carboHIPE in the form of alloy phase. The PtRu alloy nanoparticles decorated carboHIPE (PtRu/carboHIPE) demonstrated superior electrocatalytic performances towards the methanol electrooxidation by comparison with Pt/carboHIPE and commercial PtRu/C with almost same Pt content, such as the higher current density, the better long term stability and the improved CO-resistance.

Nanoporous carbon (NPC) supported Pt-Cu nanocomposites (PtxCu/NPC) with different Pt/Cu molar ratios have been successfully synthesized via NaBH4 reduction method and used as anode catalysts for direct borohydride-hydrogen peroxide fuel cell (DBHFC). The as-synthesized PtxCu/NPC electrocatalysts are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), cyclic voltammetry (CV), chronoamperometry (CA), rotating disc electrode (RDE) and fuel cell test. It has been found that the PtCu nanoparticles are uniformly dispersed on the surface of the NPC support with average size of about 2.3 nm. Besides, the PtxCu/NPC catalysts show higher activities for borohydride oxidation than that of monometallic Pt/NPC and Vulcan XC-72 carbon supported Pt2Cu (Pt2Cu/XC-72) catalysts. Especially, the DBHFC equipped with Pt2Cu/NPC as anode catalyst shows the maximum power density of 89 mW cm−2 at 25 °C.

A series of nanoporous carbon supported Pd–Zn catalysts (Pd x Zn/NPC, x = 1, 2, 3) have been successfully prepared via impregnation-reduction method and firstly employed as anode catalysts for direct borohydride-hydrogen peroxide fuel cell (DBHFC). The properties of the Pd x Zn/NPC electrocatalysts are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), cyclic voltammetry (CV), chronoamperometry (CA) and single fuel cell test. The TEM images of Pd 2 Zn/NPC catalyst reveal that the metal particles with a size of approximately 3.1 nm are uniformly dispersed on the nanoporous carbon (NPC). Besides, all the Pd x Zn/NPC catalysts exhibit enhanced catalytic activity and stability for BH 4 − electrooxidation compared to monometallic Pd/NPC in the electrochemical tests. Especially, the Pd 2 Zn/NPC catalyst exhibits the highest electrocatalytic activity toward borohydride oxidation among the four catalysts. Moreover, the DBHFC equipped with the Pd 2 Zn/NPC anode also presents an excellent cell performance with the maximum power density as high as 103.93 mW cm −2 at 25 °C.

The activated nitrogen-enriched novel carbons (a-NENCs) have been prepared by direct carbonization of polyaniline/activated mesocarbon microbead composites and further activated by 16 M HNO3. The electrochemical performances and supercapacitive behaviors of the a-NENCs in 6 M KOH, 1 M H2SO4, and 0.5 M K2SO4 solutions are evaluated by cyclic voltammetry, galvanostatic charge/discharge, electrochemical impedance spectroscopy, cyclic life, leakage current, and self-discharge measurements. The results demonstrate that the supercapacitors perform definitely supercapacitive behaviors; especially in 6 M KOH electrolyte, the supercapacitor represents much better electrochemical performance with more excellent reversibility, shorter relaxation time of 1.11 s, and nearly ideal polarizability. The maximum specific capacitance of the supercapacitors using a-NENCs as active electrode material is 85.1 F g−1 at a rate of 500 mA g−1 in 6 M KOH. These outcomes indicate that the 6 M KOH aqueous solution is a promising electrolyte for the supercapacitor with a-NENCs as electrode material.

Carbon supported Pt–Sn bimetallic nanoparticles (Pt–Sn/C) are prepared by a modified NaBH 4 reduction method in aqueous solution at room temperature, and used as the anode electrocatalyst for direct borohydride–hydrogen peroxide fuel cell (DBHFC). The physical and electrochemical properties of the as-prepared electrocatalysts are investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), cyclic voltammetry (CV), chronoamperometry (CA) and fuel cell test. XRD results show that the diffraction peaks in Pt–Sn/C catalyst shift slightly to lower 2θ values with the increase of Sn content compared with that of Pt/C catalyst, suggesting the formation of Pt–Sn alloying. TEM results show that the morphologies of Pt–Sn bimetallic nanoparticles are uniformly spherical with the particle size of about 3 nm on the carbon surface. Besides, it has been found that the Pt–Sn/C catalysts have much higher catalytic activity for the direct oxidation of BH 4 − than Pt/C catalyst, especially the Pt 67 Sn 33 /C catalyst presents the highest catalytic activity among all as-prepared catalysts. The DBHFC with Pt 67 Sn 33 /C anode catalyst and Pt/C cathode catalyst obtains the maximum power density as high as 91.5 mW cm −2 at 25 °C.

Carbon-supported Pt–Co nanoparticle catalysts (Pt–Co/C) with a mean crystallite size of approximate 2 nm are prepared by a modified NaBH4 reduction method in aqueous solution at room temperature and employed as anode catalyst for direct borohydride-hydrogen peroxide fuel cell (DBHFC). The physical and electrochemical properties are investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), chronoamperometry (CA) and fuel cell test. The results show that Pt–Co/C catalyst presents more excellent performance as DBHFC anode catalyst compared with Pt/C catalyst, especially, Pt67Co33/C catalyst presents the highest catalytic activity for BH 4 − electrooxidation among all as-prepared catalysts. The single DBHFC using Pt67Co33/C as anode catalyst and Pt/C as cathode catalyst obtains the maximum power density as high as 79.7 mW cm−2 at 25 °C.

Au/graphene nanocomposites are prepared via a one-pot chemical reduction process at room temperature, using graphene oxide (GO) and chloroauric acid (HAuCl4) as precursors. The obtained Au/graphene nanocomposites are characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). TEM shows that the Au nanoparticles with size of approximately 8.7 nm disperse randomly on the surface of graphene. XPS confirms that the Au/graphene nanocomposites show a higher atomic percentage of C/O (6.3/1), in contrast to its precursor GO (2.2/1). Electrochemical studies reveal that the Au/graphene nanocomposites have electrochemically active surface area of 9.82 m2 g−1. Besides, the influence of borohydride concentration on the as-prepared Au/graphene nanocomposites is investigated in details by cyclic voltammetry, chronoamperometry, and chronopotentiometry. The results indicate that high concentration of borohydride can significantly improve the electrochemical performance of the Au/graphene catalyst.

Carbon supported Pd hollow nanospheres (HN-Pd/C) are prepared by employing cobalt nanoparticles as sacrificial templates at room temperature in aqueous solution, and used as the anode electrocatalyst for direct borohydride-hydrogen peroxide fuel cell (DBHFC). The physical and electrochemical properties of the as-prepared nanospherical electrocatalysts are investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), linear sweep voltammetry (LSV), chronoamperometry (CA), chronopotentiometry (CP) and fuel cell test. The results show that the Pd nanospheres supported on the carbon are coreless and composed of a series of Pd nanoparticles with the average crystallite size of about 3.8 nm. Besides, the HN-Pd/C exhibits distinctly higher electrocatalytic activity for BH 4 − electrooxidation than the carbon supported Pd solid nanoparticles (SN-Pd/C), and the DBHFC using HN-Pd/C as anode electrocatalyst shows as high as 48.4 mW cm −2 power densities at a discharge current density of 54.8 mA cm −2 . Therefore, the HN-Pd/C catalyst can apparently improve the catalytic activity of BH 4 − electrooxidation and imply a promising application in the DBHFC.

Carbon supported Pt–Cu bimetallic nanoparticles are prepared by a modified NaBH4 reduction method in aqueous solution and used as the anode electrocatalyst of direct borohydride–hydrogen peroxide fuel cell (DBHFC). The physical and electrochemical properties of the as-prepared electrocatalysts are investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), cyclic voltammetry (CV), chronoamperometry (CA), chronopotentiometry (CP) and fuel cell test. The results show that the carbon supported Pt–Cu bimetallic catalysts have much higher catalytic activity for the direct oxidation of BH4− than the carbon supported pure nanosized Pt catalyst, especially the Pt50Cu50/C catalyst presents the highest catalytic activity among all as-prepared catalysts, and the DBHFC using Pt50Cu50/C as anode electrocatalyst and Pt/C as cathode electrocatalyst shows as high as 71.6 mW cm−2 power density at a discharge current density of 54.7 mA cm−2 at 25 °C.

A series of Mn2O3/carbon aerogel microbead (Mn2O3/CAMB) composites for supercapacitor electrodes have been synthesized by in situ encapsulation method. The structure and morphology of Mn2O3/CAMB are characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectrum and scanning electron microscopy (SEM). Electrochemical performances of the synthesized composites are evaluated by cyclic voltammetry and galvanostatic charge/discharge measurement. All the composites with different Mn2O3 contents show higher specific capacitance than pure CAMB due to the pseudo-capacitance of the Mn2O3 particles dispersed on the surface of CAMB. The highest specific capacitance is up to 368.01 F g−1 when 10 wt% Mn2O3 is coated on the surface of CAMB. Besides, 10%-Mn2O3/CAMB supercapacitor exhibits excellent cyclic stability, the specific capacitance still retains 90% of initial capacitance over 5000 cycles.

Bismuth–vanadium oxyfluoride (Bi 2 VO 5 F) has been synthesized using a simple, solid-state reaction process at different sintering temperatures. The structure and performance of the samples have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge/discharge experiments. The results show that bismuth–vanadium oxyfluoride belongs to a tetragonal crystal system with space group I4mm . The sample that was synthesized at 550 °C (P550) exhibits relatively good electrochemical properties. Sample P550 shows a high, initial discharge capacity of 222 mAh g −1 at a rate of 100 mA g −1 between 1.4 and 3.5 V. Sample P550 also shows acceptable electrochemical cycling properties. After the first cycle, the discharge specific capacity remains between 106 and 155 mAh g −1 , which plateaus between 2.1 and 1.9 V during the first 15 cycles.

The carbon supported Pt hollow nanospheres were prepared by employing cobalt nanoparticles as sacrificial templates at room temperature in aqueous solution and used as the anode electrocatalyst for direct borohydride-hydrogen peroxide fuel cell (DBHFC). The physical and electrochemical properties of the as-prepared electrocatalysts were investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), cyclic voltammetry (CV), chronoamperometry (CA), chronopotentiometry (CP) and fuel cell test. The results showed that the carbon supported Pt nanospheres were coreless and composed of discrete Pt nanoparticles with the crystallite size of about 2.8 nm. Besides, it has been found that the carbon supported Pt hollow nanospheres exhibited an enhanced electrocatalytic performance for BH 4 − oxidation compared with the carbon supported solid Pt nanoparticles, and the DBHFC using the carbon supported Pt hollow nanospheres as electrocatalyst showed as high as 54.53 mW cm −2 power density at a discharge current density of 44.9 mA cm −2 .

Co 3 O 4 /carbon aerogel microbead (Co 3 O 4 /CAMB) composites are prepared by in situ coating method and their supercapacitive behaviors are investigated. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectrum, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectrum are used to characterize the structure and morphology of Co 3 O 4 /CAMB. The results show that nano-sized Co 3 O 4 particles are homogenously encapsulated on the surface of CAMB. Electrochemical performances of the composite electrodes with different Co 3 O 4 amount are studied by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge measurements. It is found that Co 3 O 4 /CAMB composites show better electrochemical performance than CAMB, and the optimum content of Co 3 O 4 in Co 3 O 4 /CAMB composites is 10 wt.%. The specific capacitance of 10%–Co 3 O 4 /CAMB composite in 6 mol L −1 KOH electrolyte is about 350.18 F g −1 at a current density of 1 A g −1 . Moreover, 10%–Co 3 O 4 /CAMB composite supercapacitor exhibits relatively good high-rate capability and excellent cycle life.

The carbon supported Au-base electrocatalysts (Au (1−x) Zn x /C, 0 ≤ x (1−x) Zn x nanoparticles all were uniformly spherical no matter what Zn content changed, and the average particle size of Au (1−x) Zn x bimetallics varied from 3 to 6 nm. The electrochemical measurements revealed that the Au (1−x) Zn x /C electrocatalysts showed no activity toward the NaBH 4 hydrolysis reaction and obviously improved the catalytic activity of borohydride oxidation. Compared with Au/C anode electrocatalyst, the stability of DBFC using the Au 0.65 Zn 0.35 /C as anode electrocatalyst was apparently improved, and the maximum power density of 39.5 mW cm −2 was obtained at 20 °C.

The carbon supported Au 80 Ni 20 , Au 58 Ni 42 and Au 41 Ni 59 nanoparticles for the application of direct borohydride-hydrogen peroxide fuel cell (DBHFC) are synthesized in a sodium bis(2-ethylhexyl) sulfosuccinate (AOT) reverse micelle system. The physical and electrochemical properties are investigated by transmission electron microscopy (TEM), cyclic voltammetry, chronoamperometry, chronopotentiometry and fuel cell test. The TEM results reveal that the Au–Ni bimetallic particles are uniformly dispersed on carbon with narrow size distribution and regular spherical shape. The average size of the particles is about 3 nm. The electrochemical measurements show that Au–Ni bimetallic particles can apparently promote the electrode kinetics of BH 4 − oxidation. The DBHFCs using carbon supported Au–Ni bimetallic particles as anode electrocatalysts are fabricated. The results show that the performance of DBHFC using Au 58 Ni 42 /C as anode electrocatalyst excels markedly to the others, and the maximum power density of 45.74 mW cm −2 is obtained at 20 °C.

The carbon-supported bimetallic Au-Pd catalyst with core-shell structure is prepared by successive reduction method. The core-shell structure, surface morphology, and electrochemical performances of the catalysts are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible absorption spectrometry, linear sweep voltammetry, and chronopotentiometry. The results show that the Au-Pd/C catalyst with core-shell structure exhibits much higher catalytic activity for the direct oxidation of NaBH4than pure Au/C catalyst. A direct borohydride-hydrogen peroxide fuel cell, in which the Au-Pd/C with core-shell structure is used as the anode catalyst and the Au/C as the cathode catalyst, shows as high as 68.215 mW cm−2power density.

Au–Co alloys supported on Vulcan XC-72R carbon were prepared by the reverse microemulsion method and used as the anode electrocatalyst for direct borohydride-hydrogen peroxide fuel cell (DBHFC). The physical and electrochemical properties were investigated by energy dispersive X-ray (EDX), X-ray diffraction (XRD), cyclic voltammetry, chronamperometry and chronopotentiometry. The results show that supported Au–Co alloys catalysts have higher catalytic activity for the direct oxidation of BH 4 − than pure nanosized Au catalyst, especially the Au 45 Co 55 /C catalyst presents the highest catalytic activity among all as-prepared Au–Co alloys, and the DBHFC using the Au 45 Co 55 /C as anode electrocatalyst shows as high as 66.5 mW cm −2 power density at a discharge current density of 85 mA cm −2 at 25 °C.

Carbon aerogel (CA) microspheres were successfully synthesized by an inverse emulsion polymerization routine. Morphology and physical properties of the CA microspheres were characterized by scanning electron microscopy, N2 sorption isotherm, and transmission electron microscopy. The results showed that the CA microspheres were all fine spheres with diameters about 4 μm, and the CA microsphere was a typical mesoporous material with ordered mesoporous nano-network structure. The maximum capacitance of the electrode obtained from cyclic voltammetry was 187.08 F/g and the capacitance of the supercapacitor resulted from galvanostatic charge–discharge tests was up to 45.98 F/g. The supercapacitor using CA microsphere as electrode material presented a long cycle life, high charge–discharge efficiency, and low R s of 0.70 Ω in 6 M KOH electrolyte.

Platinum nanoparticles (Ptnano) were prepared and used in combination with single-wall carbon nanotube (SWNT) for fabricating electrochemical sensors with remarkably improved sensitivity toward diethylstilbestrol (DES). The glassy carbon (GC) electrode modified with SWNT/Ptnano composite film exhibited excellent electrochemical behaviors toward the redox of DES. Compared with the bare GC electrode and SWNTs film modified GC electrode, the redox peak currents at the SWNTs/Ptnano composite film modified GC electrode was enhanced greatly. The experimental parameters, which influence the peak current of DES, were optimized. Under optimal conditions, a linear response of DES was obtained in the range from 1.0 × 10−7 to 2.0 × 10−5 mol L−1 (R = 0.997) and with a limit of detect (LOD) of 1.5 × 10−8 mol L−1. The proposed procedure was successfully applied to determine the active ingredient in the DES tablet with satisfactory results.

A sensitive electrochemical method was developed for the determination of doxorubicin at a glassy carbon electrode (GCE) modified with a nano-titania (nano-TiO2)/nafion composite film. Nano-TiO2 was dispersed into nafion to give a homogeneous suspension. After solvent evaporation, a uniform film of nano-TiO2/nafion composite was obtained on the GCE surface. The nano-TiO2/nafion composite film modified GCE exhibited excellent electrochemical behavior toward the reduction of doxorubicin. Compared to the reduction of doxorubicin at the bare GCE, the reduction current of doxorubicin at the nano-TiO2/nafion composite film modified GCE was greatly enhanced. Based on this, a novel voltammetric method was applied to the determination of doxorubicin. The experimental parameters that influence the reduction current of doxorubicin, were optimized. Under optimal conditions, a linear response of doxorubicin was obtained in the range from 5.0 × 10−9 to 2.0 × 10−6 mol L−1 (R = 0.998) and with a limit of detection (LOD) of 1.0 × 10−9 mol L−1(S/N = 3). The RSD of the measurement is 4.7%, and the RSD of the inter-electrode is of 5.1% which indicate the reproducibility of this method. The current response decreased only by around 3.8% of its initial response after 2 weeks exposing the electrode in air. The procedure was applied to assay doxorubicin in human plasma samples with the recoveries of 94.9–104.4%.

A sensitive and selective electrochemical method was developed for the amperometric determination of ascorbic acid (AA) at a glassy carbon electrode (GCE) modified with single-wall carbon nanotubes-dihexadecyl hydrogen phosphate (SWNT-DHP) composite film. The SWNT-DHP composite film modified GCE was characterized with SEM. The SWNT-DHP composite film modified GCE exhibited excellent electrocatalytic behaviors toward the oxidation of AA. Compared with the bare GCE, the oxidation current of AA increased greatly and the oxidation peak potential of AA shifted negatively to about -0.018 V (vs. SCE) at the SWNT-DHP composite film modified GCE. The experimental parameters, which influence the oxidation current of AA, were optimized. Under the optimal conditions, the amperometric measurements were performed at a applied potential of -0.015 V and a linear response of AA was obtained in the range from 4 × 10 - 7 to 1 × 10 - 4 not L - 1 and with a limit of detect (LOD) of 1.5 × 10 - 7 mol L - 1 . The interferences study showed that the SWNT-DHP composite film modified GCE exhibited good sensitivity and excellent selectivity in the presence of high concentration uric acid and dopamine. The proposed procedure was successfully applied to detect AA in human urine samples with satisfactory results.

The electroanalytical behaviors of the endocrine-disrupting chemical trifluralin have been studied at a nanostructuring electrode. The nanostructuring electrode was fabricated by coating a uniform multi-wall carbon nanotubes/dihexadecyl hydrogen phosphate (MWNTs/DHP) film on glassy carbon electrode (GCE). The reduction peak currents of trifluralin increased remarkably and the reduction peak potential shifted positively at the nanostructuring electrode, compared with that at a bare GCE. The results showed that this nanostructuring electrode exhibited excellent enhancement effects on the electrochemical reduction of trifluralin. Consequently, a simple and sensitive electroanalytical method was developed for the determination of trifluralin. Under optimal conditions, a linear response of trifluralin was obtained in the range from 5.0 × 10−9 to 6.0 × 10−6 mol L−1 (r = 0.998) and with a limit of detect (LOD) of 2.0 × 10−9 mol L−1. The proposed procedure was successfully applied to determine trifluralin in soil samples with satisfactory results.

A Li-rich layered cathode material Li1.15[(Ni1/3Co1/3Mn1/3)0.5(Ni1/4Mn3/4)0.5]0.85O2 with a spherical core–shell structure was firstly synthesized by a co-precipitation route. In this material, the Li1.15[Ni1/3Co1/3Mn1/3]0.85O2 core was completely encapsulated by a Li1.15[Ni1/4Mn3/4]0.85O2 shell. The structure and morphology of the as-prepared core–shell structured material were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD results indicate that the core–shell structured material has a typical layered structure with the existence of a Li2MnO3-type integrated component. Spherical morphologies with an inner core and outer shell layer are clearly observed by SEM. A half cell using the core–shell structured cathode material showed a high capacity of 242 mA h g−1 at a rate of 0.1 C in a voltage range of 2.0–4.8 V. Especially, the core–shell structured cathode material represents excellent lithium intercalation stability compared to the Li1.15[Mn1/3Co1/3Mn1/3]0.85O2 core, and an improved rate capability compared to the Li1.15[Ni1/4Mn3/4]0.85O2 shell. A synergetic effect of the positive attributes of the two materials is achieved by the formation of the core–shell architecture. Therefore, the as-prepared core–shell structured Li1.15[(Mn1/3Ni1/3Co1/3)0.5(Ni1/4Mn3/4)0.5]0.85O2 is very effective for improving the electrochemical behavior of Li-rich layered cathode materials in the high-performance lithium ion batteries.

Fe1−xCoxF3 (x = 0, 0.03, 0.05, 0.07) compounds are synthesized via a liquid-phase method. To further improve their electrochemical properties, a ball milling process with acetylene black (AB) has been used to form Fe1−xCoxF3/C (x = 0, 0.03, 0.05, 0.07) nanocomposites. The structure and performance of the samples have been characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDX), charge–discharge tests, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and the galvanostatic intermittent titration technique (GITT). It is found that Co-doping significantly improves the electrochemical performance. Fe0.95Co0.05F3/C exhibits excellent electrochemical performance with discharge capacities of 151.7, 136.4 and 127.6 mA h g−1 at rates of 1C, 2C and 5C in the voltage range of 2.0–4.5 V vs. Li+/Li, and its capacity retentions remain as high as 92.0%, 92.2% and 91.7%, respectively, after 100 cycles. Co-doping could decrease the charge transfer resistance, increase the lithium diffusion coefficient during the lithiation process and improve the electrochemical reversibility. The preparation of Co-doped FeF3/C offers a new method to improve the performance of FeF3: cationic doping, which is a significant step forward for developing high-power lithium batteries.