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In this study, nanoflakes of B12S were fabricated by plasma-assisted reaction of sulfur dichloride in an ionic liquid at room temperature using europium boride as a hard template. The nanoflakes had an average width and thickness of about 3 1urn and 9.6 nm, respectively, and a large specific surface area of 1197.2 m2 g 1. They behaved like typical electric double-layer capacitors with a capacitance of 201.2 F g 1 at 0.2 mA cm 2 During capacitive deionization to recover rare-earth ions, the nanoflakes had higher adsorption selectivity for Sm3+ than for other competing ions present in real mine waste water. This is due to the strong interaction of the electron-concentered S-groups (S’’’) of the nanoflakes with S m3+. This provides an alternative to construct efficient systems to specifically remove Sm3+ from aqueous solution using B12S nanoflakes. This process demonstrates that other boron sulfide compounds can be used to recover valuable ions by capacitive deionization.

Amorphous Eu0.9Ni0.1B6 nanoparticles are fabricated through a coreduction approach with the aid of phosphite ions under a liquid plasma field. This approach achieves not only better gas response/re...

Amorphous LiEuTiO4 nanovesicles were fabricated using in situ formed Eu nanoparticles as sacrificial templates. Samples fabricated with these nanovesicles exhibited a good rate performance together with a large reversible discharge capacity of 285.1 mAh g−1 at 0.2 A g−1 and 185.7 mAh g−1 at 10 A g−1 and had an excellent cycle performance with a huge reversible discharge capacity of 282 mAh g−1 after 1000 cycles at 0.1 A g−1. These advantageous characteristics are attributed its unique structure, which reduces the length of Li+/electron transportation and increases the interface between the electrolyte and the electrode. A solid-electrolyte boundary film was formed on the surface of the LiEuTiO4 anode during cycling. However, the rate and cyclic properties of the sample improved after adding vinylene carbonate. Those results demonstrate that LiEuTiO4 nanovesicles can function as an ideal low operating voltage anode material in high-rate lithium ion batteries intended for electric vehicles or hybrid electric vehicles without a corresponding reduction in the battery voltage or energy density.

Fiber-shaped supercapacitors (FSCs) have great promises in wearable electronics applications. However, the limited specific surface area and inadequate structural stability caused by the weak interfacial interactions of the electrodes result in relatively low specific capacitance and unsatisfactory cycle lifetime. Herein, solid-state FSCs with high energy density and ultralong cycle lifetime based on polyaniline (PANI)/sulfur-doped TiO2 nanotube arrays (PANI/S-TiO2) are fabricated by interfacial engineering. The experimental results and ab initio calculations reveal that S doping can effectively promote the conductivity of titania nanotubes and increase the binding energy of PANI anchored on the electrode surface, leading to a much stronger binding of PANI on the surface of the electrode and excellent electrode structure stability. As a result, the FSCs using the PANI/S-TiO2 electrodes deliver a high specific capacitance of 91.9 mF cm–2, a capacitance retention of 93.78% after 12 000 charge–discharge cycl...

Correction for ‘Retracted Article: Mesoporous amorphous FeOF nanococoons for high-rate and long-life rechargeable sodium-ion batteries’ by Shi Yan Fu et al., J. Mater. Chem. A, 2015, 3, 16716–16727, https://doi.org/10.1039/C5TA04288G.

O-Doped BN nanosheets with a thickness of 1.033 nm were prepared via the direct reaction of CuB23 with NOCl at room temperature in ionic liquids. It had a large high specific surface area of 858 m2 g−1, and showed a high electrical conductivity of 34.3 S m−1 and a good specific capacity of 187 F g−1. Meanwhile, the obtained sample demonstrated excellent performance as the electrode material for capacitive deionization (CDI) to remove Cd2+ from water in a wide range of concentrations from 0.05 to 600 ppm with a maximum adsorption capacity of 2281 mg g−1. It is attributed to its unique structural characteristics and the ability of its NO– groups to coordinate Cd2+ which promotes the electrosorption. More importantly, it exhibited outstanding capability for the total, rapid, and simultaneous removal of multiple metal ions (Zn2+, Cd2+, Pb2+, Ni2+, Co2+, Cu2+, Mg2+, Ca2+, Fe2+, Fe3+ and Na+) by CDI within 20 min. These results suggest promising applications of our BNO nanosheets for water purification and water-softening devices based on CDI.

Novel mesoporous B–N–O–H nanofoam was prepared using CuB23 and ammonium chloride precursors under O2 in ionic liquids via a solution plasma technique. It had a large specific surface area of 1023 m2 g−1, and exhibited high electrical conductivity of 20.8 S m−1 and good specific capacity of 184 F g−1 in 600 mg L−1 methylene blue aqueous solution at a current density of 0.2 mA cm−2. Furthermore, the nanofoam exhibited a high adsorption capacity for cationic dyes, especially methylene blue, with well-controlled recycling behavior. Meanwhile, the methylene blue/acid orange 7 mixture could be easily separated for reuse by the strong electrostatic interaction. The good separation of methylene blue/Rhodamine B was attributed to the stronger coordination between methylene blue and the B–N–O–H nanofoams in comparison with that of Rhodamine B, and the advantage of the smaller methylene blue in competitive adsorption at higher flow rates. These results indicate that the present B–N–O–H nanofoam may have promising applications in the field of water purification, including enrichment or even total separation of dyes during wastewater treatment for reuse.

Mesoporous face-centered-cubic (fcc) In4Ni alloy nanorices (NRs) were successfully synthesized as superior catalysts for N2H4 dehydrogenation in aqueous solution via a facile solution plasma technique (SPT) in an ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]). This incorporation introduces basic sites for dehydrogenation. Also, the synthesis of In and Ni weakens the interactions among generated adspecies such as H2 and NHx and surface metal atoms. Alongside their unique NR structure, the as-prepared fcc-In4Ni alloy NRs exhibited superior performance for N2H4 dehydrogenation in aqueous solution. The activation energy of the fcc-In4Ni alloy NRs was 38.9 ± 1.0 kJ mol(-1). The NRs were also found to be stable for catalytic N2H4 dehydrogenation in aqueous solution, providing an average TOF value of 82.0 (mol of H2 (mol of active In4Ni min)(-1)) over 30 h reaction. These fcc-In4Ni alloy NRs have demonstrated exceptional performance, which indicates that the construction of hydrogen-producing systems from N2H4, capable of matching the performance of NaBH4 and NH3BH3 hydrogen-producing systems for fuel-cell applications, is a promising possibility.

Urchin-like amorphous Ni2B alloys were successfully prepared for the first time from a mixture of Ni(NH3)6(2+) and polyvinyl alcohol (PVA) via a solution plasma process (SPP). The as-synthesized samples were characterized by X-ray powder diffraction (XRD), inductively coupled plasma atomic emission spectrometry (ICP-AES) X-ray photoelectron spectroscopy (XPS), scanning transmission electron microscopy (STEM), selected-area electron diffraction patterns (SAED) and nitrogen adsorption-desorption isotherms. In the performance test, the obtained Ni-B urchins showed great antibacterial activities, comparable with those of amikacin and kanamycin, especially towards Pseudomonas aeruginosa (P. aeruginosa). Meanwhile, the magnetic properties of Ni-B urchins are enhanced in comparison with those of conventional Ni-B. During hydrous hydrazine (N2H4) decomposition, the dehydrogenation performance of Ni-B urchins is superior to those of Raney Ni and conventional Ni-B. The enhanced catalytic performance of Ni-B urchins is attributed to their high surface area of active species nickel and the enhanced intrinsic activity resulting from their unique structure.

Mesoporous face-centered-cubic (fcc) In4Ni alloy nanorices (NRs) were successfully synthesized as superior catalysts for N2H4 dehydrogenation in aqueous solution via a facile solution plasma technique (SPT) in an ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]). This incorporation introduces basic sites for dehydrogenation. Also, the synthesis of In and Ni weakens the interactions among generated adspecies such as H2 and NHx and surface metal atoms. Alongside their unique NR structure, the as-prepared fcc-In4Ni alloy NRs exhibited superior performance for N2H4 dehydrogenation in aqueous solution. The activation energy of the fcc-In4Ni alloy NRs was 38.9 ± 1.0 kJ mol(-1). The NRs were also found to be stable for catalytic N2H4 dehydrogenation in aqueous solution, providing an average TOF value of 82.0 (mol of H2 (mol of active In4Ni min)(-1)) over 30 h reaction. These fcc-In4Ni alloy NRs have demonstrated exceptional performance, which indicates that the construction of hydrogen-producing systems from N2H4, capable of matching the performance of NaBH4 and NH3BH3 hydrogen-producing systems for fuel-cell applications, is a promising possibility.

Amorphous EuB6 was successfully prepared having a high specific surface area (221.3 m2 g-1) via the reaction between EuCl3 and B2H6 in the presence of liquid plasma in an ionic liquid environment. The material exhibits an immediate, lasting, and highly selective response toward formaldehyde at room temperature with a detection limit of 50 ppb. The good sensing performance of the amorphous EuB6 material is attributed to the strong interaction between formaldehyde and the increased number of accessible electron-rich surface Eu sites.

6.8 nm face-centered-cubic indium nanocubes were prepared via plasma-assisted hydrogen reduction in ionic liquid 1-butyl-3-methylimidazolium chloride and KClO4 as a {100}-facet director. The nanocubes exhibited excellent dehydrogenation activity toward aqueous hydrazine owing to their localized surface plasmon resonance.

We developed a co-reduction method to synthesize octahedral, truncated octahedral, and cubic Rh2Ni nanocrystals. The shape/size distribution, structural characteristics, and composition of the Rh2Ni nanocrystals are investigated, and their possible formation mechanism at high temperatures in margaric acid/1-aminoheptadecane solution in the presence of tetraethylgermanium and borane trimethylamine complexes is proposed. A preliminary probing of the structure-activity dependence of the surface "clean" Rh2Ni nanocrystals supported on carbon towards hydrazine (N2H4) in aqueous solution dehydrogenation revealed that the higher the percentage of {111} facets, the higher is the activity and H2 selectivity of the nanocrystals. This result was attributed to the {111} facets not only introducing more basic sites, but also weakening the interaction between the produced adspecies (including H2 and NHx) and surface metal atoms in comparison with those of {100} facets. Furthermore, the as-prepared Rh2Ni nanooctahedra exhibited 100% H2 selectivity and high activity at room temperature for H2 generation via N2H4 decomposition. The activation energy of the Rh2Ni nanooctahedra was 41.6 ± 1.2 kJ mol(-1). The Rh2Ni nanooctahedra were stable catalysts for the hydrolytic dehydrogenation of N2H4, providing 27 723 total turnovers in 30 h. Our work provides a new perspective concerning the possibility of constructing hydrogen-producing systems based on N2H4 and surface "clean" Rh2Ni nanocrystal catalysts with defined shapes supported on carbon that possess a competitive performance in comparison with NaBH4 and NH3BH3 hydrogen-producing systems for fuel cell applications.

Hollow amorphous NaFePO4 nanospheres were prepared on a large scale by a simple in situ hard template process, wherein the hollow nanospheres exhibited a high storage capacity and high rate as a cathode material for sodium-ion batteries.

A novel solution plasma processing approach was developed to synthesize mesoporous amorphous FeOF nanococoons on a large scale via using NaF and FeCl3·xH2O as the precursors, and CO2 released from the hydrolysis of urea as the growth director. The obtained mesoporous amorphous FeOF nanococoons deliver a reversible capacity of 238.9 mA h g−1 at a current rate of 1 A g−1 and show almost no degradation, even after 3000 cycles by adopting the optimized 1.0 M sodium trifluoromethanesulfonate (NaTFSA) in triglyme (TGM) as the electrolyte and tuning the cut-off voltage to 1.3 V. Furthermore, the nanococoons exhibit a capacity of 190.4 mA h g−1 at an ultrahigh current density of 20 A g−1 because of the coexisting pseudocapacitance-type reaction. Meanwhile, a commercial 18650-type battery was fabricated that exhibited a stable discharge capacity of 4897 mA h at 4 A for 300 cycles, which allows for consideration of this type of room-temperature battery in commercial utilization. The superior electrochemical performance of the mesoporous amorphous FeOF nanococoons is because of the collaboration of the optimized electrolyte, controlling the terminal voltage to 1.3 V, and their particular nanostructure, which significantly improve the ionic and electronic transport and intercalation kinetics of Na ions.

Retraction of ‘Mesoporous multiwalled carbon nanotubes as supports for monodispersed iron–boron catalysts: improved hydrogen generation from hydrous hydrazine decomposition’ by Dong Ge Tong et al., J. Mater. Chem. A, 2013, 1, 358–366.

We prepared N- and H-co-doped Cu-B as sensing materials for hydrogen chloride (HCl) detection at room temperature through a liquid plasma technique for the first time. Being used as an advanced Cu-B-N-H-based capacitive sensor, it showed a linear response to HCl at concentrations as low as 200ppb, with a detection limit of 10ppb. The sensor also featured good detection selectivity towards HCl versus methane, nitrogen dioxide, hydrogen, and benzene. Furthermore, the sensor showed outstanding HCl-sensing performance compared with those of previously reported sensing materials.

Black mesoporous anatase TiO2 nanoleaves with an electro-conducting trivalent Ti have been successfully synthesized via a facile solution plasma process and their electrochemical aluminum storage performance in Al(NO3)3 aqueous solution is investigated. The unique structure and highly extraordinary electro-conducting physical properties of the as-formed black mesoporous anatase TiO2 nanoleaves facilitates aluminum ion diffusion and electronic transport. Meanwhile, the bulk intercalation of aluminum ions was accompanied by the phenomenon of interfacial aluminum ion storage in the black mesoporous anatase TiO2 nanoleaves. As a result, they not only exhibit a sustained high aluminum storage performance 278.1 mA h g−1 (corresponding to Al0.27TiO2) at a current density of 0.05 A g−1, but also exhibit an excellent rate capability (141.3 mA h g−1 at a current density of 2.0 A g−1) with excellent cycling stability. The as-prepared black mesoporous anatase TiO2 nanoleaves electrode is promising for secondary aqueous battery applications with high power and energy densities.

Rh-doped LiNi0.5Mn1.5O4 has been prepared for the first time as the 5 V cathode materials of lithium ion batteries. The samples were characterized by X-ray diffraction, scanning electron microscopy, inductively coupled plasma analysis and electrochemical measurements. The results indicated that the rate capability and cycling stability of LiNi0.5Mn1.5O4 at 25 and 55 °C was effectively improved by doping with 2 mol% Rh. At a 3000 mA g−1 (20 °C) charge/discharge rate, the LiNi0.48Rh0.02Mn1.5O4 sample still delivered an initial discharge capacity of 92.4 mAh g−1 at 25 °C. Furthermore, it maintained 83.6% of its initial capacity after 300 cycles under a 150 mA g−1 current rate (1 °C) at 55 °C. These improvements were principally attributed to Rh-substitution, which not only enhanced the electronic conductivity and lithium ion diffusion ability of LiNi0.5Mn1.5O4, but also suppressed the destruction of electrolyte during cycling. The thermal stability of LiNi0.5Mn1.5O4 was also enhanced by Rh-doping.

A hydrothermal approach was developed to synthesize monodisperse Li9V3(P2O7)3(PO4)2 microspheres consisting of nanoplates arranged in an open three-dimensional mesoporous structure. Conductive polyaniline (PANI) was deposited onto the Li9V3(P2O7)3(PO4)2 microspheres to increase their rate capability. The samples were investigated using X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, N2 adsorption–desorption, tap density, Fourier transform infrared spectroscopy, and electrochemical methods. The Li9V3(P2O7)3(PO4)2/PANI microspheres were found to have excellent rate capability and cycle stability, exhibiting a discharge capacity of 139 mAh g−1 at 0.1 C, which remained approximately 110 mAh g−1 at 5 C and 94 mAh g−1 at 10 C for a total of 500 cycles at 2.5–4.6 V.

A facile, reliable, and robust synthetic method for the preparation of monodisperse Ni3Fe single-crystalline nanospheres with 182.3 m2 g−1 specific surface area is reported. The results of an investigation of the shape/size distribution, structural characteristics, and composition of these Ni3Fe nanospheres are presented, and a possible mechanism for the formation of the nanospheres at high temperatures in a cetylamine–palmitic acid solution in the presence of tri-iso-butyl thallium and borane trimethylamine complexes is proposed. During the decomposition of hydrazine, when supported on carbon (Ni3Fe/C), the monodisperse Ni3Fe nanospheres exerted 100% H2 selectivity, and showed exceedingly high activity at room temperature. The decomposition reaction is first-order in Ni3Fe concentration, but zero-order in N2H4 concentration; the activation energy was 48.1 ± 2.0 kJ mol−1. Furthermore, the Ni3Fe/C was a stable catalyst for N2H4 hydrolytic dehydrogenation; it provided 15 840 total turnovers in 30 h. An Ni3Fe nanosphere-based catalyst such as this that is efficient under mild reaction conditions represents a promising step toward the practical development of N2H4 as a feasible hydrogen storage medium for fuel cell applications.

Multiwalled carbon nanotube supported iron–boron catalysts (Fe–B/MWCNTs) were developed via the chemical reduction of aqueous sodium borohydride with iron chloride for hydrolysis of hydrous hydrazine (N2H4). The effects of loading, N2H4 concentration, reaction temperature and supporting materials on the as-prepared Fe–B/MWCNTs were investigated. A high H2 generation rate of 34.2 L h−1 g−1 catalyst for the 9.86 wt% Fe–B/MWCNTs is achieved with 97.0% H2 selectivity at room temperature. Furthermore, the hydrolysis reaction is zero order with respect to N2H4 concentration in the range 0.1–5 mol L−1, and the activation energy is 46.7 ± 1.3 kJ mol−1 for 9.86 wt% Fe–B/MWCNTs. The 9.86 wt% Fe–B/MWCNTs are stable catalysts for N2H4 hydrolytic dehydrogenation as they provide 114480 total turnovers in 30 h. The improved performance of Fe–B/MWCNTs is a promising step towards the application of N2H4 as a chemical hydrogen storage material.

Nitrogen-doped titanium dioxide (N-doped TiO 2 ) microspheres with porous structure were prepared via the nitrogen-assisted glow discharge plasma technique at room temperature for the first time. The samples were characterized by X-ray diffraction, scanning electron microscopy, nitrogen adsorption–desorption measurement, UV–Vis diffuse reflectance spectra, photoluminescence spectroscopy and X-ray photoelectron spectroscopy. The results indicated that the plasma treatment did not affect the porous structure of the TiO 2 microspheres. With the plasma treatment, the N contents in the samples increased. During the photocatalytic degradation of methylene blue under simulative sunlight irradiation, the sample after plasma treatment for 60 min (N-TiO 2 -60) exhibited higher photocatalytic activity than those of the TiO 2 microspheres, P25 and other N-doped TiO 2 microspheres. Furthermore, the N-TiO 2 -60 showed excellent antibacterial activities towards Escherichia coli under visible irradiation. These should be attributed to the enhancement of the visible light region absorption for TiO 2 after N-doping. Electrochemical data demonstrated that the N-doping not only enhanced the electrochemical activity of TiO 2 , but also improved the reversibility of Li insertion/extraction reactions and the rate behavior of TiO 2 during charge–discharge cycles.

Nickel oxide (NiO) nanoflowers were successfully prepared, for the first time, from a mixture of Ni(NH3)62+ and triethanolamine via a solution plasma process. The as-synthesized samples were characterized by X-ray powder diffraction, scanning electron microscopy, nitrogen adsorption–desorption isotherms and transmission electron microscopy. Based on the experimental results, a possible formation mechanism for the NiO nanoflowers was proposed. In addition, the gas responses of NiO nanoflowers were investigated towards 100 ppm of a variety of gases including H2, NO2, CO, toluene, NH3, and H2S at 150 °C. It was found that NiO nanoflowers are promising NO2 sensing materials owing to their excellent response and selectivity.

Single-crystalline zinc oxide (ZnO) nanospheres with high specific surface area were successfully prepared by solution plasma process. These nanospheres showed great antibacterial activities, as good as amikacin or kanamycin, especially towards Salmonella typhimurium . They also displayed better photocatalytic activity in degradation of methyl orange (MO) in aqueous solution than those of Degussa P25 and commercial ZnO. After UV irradiation for 8 min, MO was totally degraded over ZnO nanospheres, whereas only 60% and 75% of MO was degraded over commercial ZnO and P25, respectively. Furthermore, they had a good optical property with a strong UV emission at 380 nm and a weak green emission at 535 nm.

Retraction of ‘Novel mesoporous amorphous B–N–O–H nanofoam as an electrode for capacitive dye removal from water’ by Ming Ming Chen et al., J. Mater. Chem. A, 2017, 5, 21400–21413.

Retraction of ‘Monodisperse Ni3Fe single-crystalline nanospheres as a highly efficient catalyst for the complete conversion of hydrous hydrazine to hydrogen at room temperature’ by Dong Ge Tong et al., J. Mater. Chem. A, 2013, 1, 6425–6432.

Retraction of ‘One-pot synthesis of O-doped BN nanosheets as a capacitive deionization electrode for efficient removal of heavy metal ions from water’ by Ming Ming Chen et al., J. Mater. Chem. A, 2017, 5, 17029–17039.

Retraction of ‘Synthesis of octahedral, truncated octahedral, and cubic Rh2Ni nanocrystals and their structure–activity relationship for the decomposition of hydrazine in aqueous solution to hydrogen’ by Chun Li et al., Nanoscale, 2016, 8, 7043–7055.

Retraction of ‘Mesoporous amorphous FeOF nanococoons for high-rate and long-life rechargeable sodium-ion batteries’ by Shi Yan Fu et al., J. Mater. Chem. A, 2015, 3, 16716–16727.

Retraction of ‘Preparation of face-centered-cubic indium nanocubes and their superior dehydrogenation activity towards aqueous hydrazine with the assistance of light’ by Fang Luo et al., J. Mater. Chem. A, 2016, 4, 17665–17672.

Retraction of ‘Black mesoporous anatase TiO2 nanoleaves: a high capacity and high rate anode for aqueous Al-ion batteries’ by Ying Juan He et al., J. Mater. Chem. A, 2014, 2, 1721–1731.

Retraction of ‘Hollow amorphous NaFePO4 nanospheres as a high-capacity and high-rate cathode for sodium-ion batteries’ by Chun Li et al., J. Mater. Chem. A, 2015, 3, 8265–8271.

Biomorphic nickel oxide microtubes with mesoporous structure were successfully prepared from cotton templates. By the infiltration of nickel nitrate solution into cotton, followed by calcination at 673 K in oxygen for 1 h, the product was obtained. The sample was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and nitrogen absorption–desorption. Compared with regular nickel oxide prepared without using cotton, biomorphic nickel oxide exhibited an enhanced antimicrobial activities, ferromagnetic behavior and photocatalytic activities due to the formed special microstructure.

Copper oxide (CuO) vegetable sponges with mesoporous structure were successfully prepared from pine tree needles cellulose as templates. The sample was characterized by X-ray diffraction, scanning electron microscopy and nitrogen absorption–desorption. In the performance test, the obtained CuO vegetable sponges showed great antibacterial activities, as good as penicillin and kanamycin, especially towards Streptococcus faecalis. They also displayed active photocatalytic degradation of rhodamine B molecules in aqueous solution. Electrochemical data demonstrated that the CuO vegetable sponges were capable of delivering a specific capacitance of 440 F g−1 at a current density of 1 A g−1 and offered good specific capacitance retention of 95.1% after 1,000 continuous charge–discharge cycles even at 5 A g−1.

The effect of rhodium (Rh) substitution on the electrochemical properties of LiFePO4/C cathode materials was studied. The results of electrochemical measurement show that Rh substitution can improve the rate capability of LiFePO4/C. However, heavy Rh substitution causes a discharge capacity loss. The LiFe0.975Rh0.025PO4/C sample shows an excellent high rate performance and its discharge capacity at a 10 C rate is 117.0 mAh g−1 with a discharge voltage plateau of 3.31–3.0 V versus Li/Li+. LiFe0.975Rh0.025PO4/C also shows a noticeably better cycling life at high temperature than LiFePO4/C. It still remains a capacity of 135.4 mAh g−1 at the 300th cycle at 55 °C under a 1 C rate, which is 82.0% of its initial capacity.

Monodispersed cobalt–boron spherical nanoparticles have been prepared through solution plasma processing in the presence of hexadecyltrimethyl ammonium bromide for the first time. The particle size of cobalt–boron can be adjusted by changing either the plasma time or the concentration of hexadecyltrimethyl ammonium bromide. The samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. During the decomposition of hydrous hydrazine, the obtained monodispersed cobalt–boron spherical nanoparticles exhibit higher catalytic activity and hydrogen selectivity than regular cobalt–boron prepared by direct reduction of Co2+ with BH4−. The experimental investigations indicate that hydrous hydrazine along with the monodispersed cobalt–boron spherical nanoparticles may find application in small-scale on-board hydrogen storage and supply.

Magnetically recyclable Co–B hollow nanospindles have been prepared by using poly(styrene-co-methacrylic acid) nanospindles as scarified templates for the first time. The effect of the weight ratio of poly(styrene-co-methacrylic acid) to Co(OAc)2 on the structure of Co–B hollow nanospindles is not significant. In the hydrolysis of ammonia borane to release H2, the activity of Co–B hollow nanospindles was much higher than that of regular Co–B prepared without templates. Their catalytic performance is comparable to that of the reported Pt black concerning hydrogen yield. The favorable activity is attributed to the large specific surface area and hollow structure. In addition, Co–B hollow nanospindles have good reusability in the application due to their unique magnetic properties.

The crystallinity of amorphous Co–B alloy prepared from Co(NO 3 ) 2 and KBH 4 was improved by low-temperature ethanol-thermal treatment without occurrences of decomposition and side reaction. All samples were characterized by X-ray powder diffraction (XRD), scanning electron micrograph (SEM), inductively coupled plasma (ICP), X-ray photoelectron spectroscopy (XPS), specific surface area ( S BET ), cyclic voltammetry (CV), and charge–discharge test. It is found that Co–B alloy without ethanol-thermal treatment has poor electrochemical utilization and shows only an initial discharge capacity of 137 mAh g −1 at a constant current of 100 mA g −1 . After being ethanol-thermal treated, the charge–discharge reversibility was improved. Among all the electrodes, the Co–B alloy treated for 12 h has the highest initial discharge capacity of 330 mAh g −1 due to the enhanced synergistic effect between Co and B. However, the Co–B alloy treated for 48 h shows very good cycling performance for its higher crystallinity. After 50 cycles, it still has a discharge capacity of 270 mAh g −1 with a capacity retention of 97.5%.

Co-B flowers with mesoporous structure were first prepared via reduction of cobalt acetate by potassium borohydride in the presence of complexing agent ethylenediamine. The as-prepared Co-B flowers were characterized by Fourier transform infrared spectroscopy, X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, inductively coupled plasma atomic emission spectroscopy, X-ray photoelectron spectroscopy, N2 adsorption–desorption, and magnetic performance test. The Co-B flowers exhibited enhanced coercivity, and weakened saturation magnetization and remanet magnetization as compared with the regular Co-B. During the hydrolysis of KBH4, the Co-B flowers exhibited higher catalytic activity than the regular Co-B. It is attributed to the larger specific surface area and mesoporous channels. During the successive reactions, the conversion of KBH4 over Co-B flowers was about 97%. The average H2 generation rate of Co-B flowers was 4620 mL/min/g-catalyst in 1.5 wt% NaOH + 15 wt% KBH4 solution, which may give a successive H2 supply for a 748 W polymer electrolyte membrane fuel cell (PEMFC) at 100% H2 utilization.

The single phase of LiCo 0.3 Ni 0.7 O 2 was prepared by oxidation-ion exchange of β-Co 0.3 Ni 0.7 (OH) 2 and LiOH at low temperature. The optimal synthetic conditions were determined as that the reaction was carried out at 120 °C for 12 h with a eight-fold LiOH added before the addition of oxidant (the molar ratio of K 2 S 2 O 8 :β-Co 0.3 Ni 0.7 (OH) 2 is 1) and the obtained sample was washed to pH 11. The synthesized sample exhibits an initial discharge capacity of 130.0 mAh g −1 with 70.0% coulombic efficiency due to lower crystallinity. After heat treatment at 750 °C for 5 h, the initial discharge capacity is increased to 165.1 mAh g −1 and with a better capacity retention of 95.7% after 50 cycles, which is attributed to the improvement of the structural integrity. It suggests that the oxidation-ion exchange method together with heat treatment process is a very promising route to prepare the cathode material with good electrochemical performance for lithium ion batteries.

Mesoporous Co–B with worm-like morphology was firstly prepared via reduction of cobalt acetate by potassium borohydride in the presence of triblock copolymer templates. The as-prepared mesoporous Co–B was characterized by Fourier transform infrared (FTIR), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), inductively coupled plasma (ICP), X-ray photoelectron spectroscopy (XPS), and N 2 adsorption–desorption. During the hydrolysis of KBH 4 , the mesoporous Co–B exhibited much higher catalytic activity than the regular Co–B. It is attributed to the larger specific surface area (163.77 m 2 /g) and mesoporous channels. The average H 2 generation rate of the mesoporous Co–B was 3523 mL/min g catalyst in 1.3 wt% NaOH + 13 wt.% KBH 4 solution at 286 K, which may give a successive H 2 supply for a 571 W polymer electrolyte membrane fuel cell (PEMFC) at 100% H 2 utilization. Furthermore, the as-prepared mesoporous Co–B with high specific surface area is expected to find applications in many catalytic hydrogenation reactions.

The single phase of LiCo0.3−xGaxNi0.7O2 (x = 0, 0.05) was synthesized by a sol–gel method. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical performance. The powders are homogeneous and have a good-layered structure. The synthesized LiCo0.25Ga0.05Ni0.7O2 exhibits better electrochemical performance with an initial discharge capacity of 180.0 mAh g−1 and a capacity retention of 95.2% after 50 cycles between 2.8 and 4.4 V at 0.2C rate. The study on the structural evolution of the material during the cycling shows that Ga-doping improves the structure stability of LiCo0.3Ni0.7O2 at ambient temperature and 55 °C. Meanwhile, Ga-doping not only suppresses the alternating current (AC) impedance of LiCo0.3Ni0.7O2 but also promotes the Li+ diffusion in LiCo0.3Ni0.7O2. Furthermore, thermal stability of the charged LiCo0.25Ga0.05Ni0.7O2 is improved, which may be attributed to the retard of O2 evolution in LiCo0.3Ni0.7O2 and the suppression of electrolyte oxidation during cycling by Ga-doping.

Layered LiCo0.975Ga0.025O2 was prepared by a sol–gel method and its structure, electrochemical and thermal properties were compared with those of LiCoO2 synthesized by the same method. The results showed that gallium doping improved the capacity retention of LiCoO2 while it lowered the initial discharge capacity. The improvement of capacity retention was prominent when the cycle tests were carried out at higher cut-off voltage and larger current rate. Cyclic voltammetry test indicated that the phase transition of LiCoO2 was suppressed by gallium doping. XRD of LixCo0.975Ga0.025O2 indicated that gallium doping brought about fewer changes in the c-axis during charge. Furthermore, the gallium doping also significantly enhanced the chemical diffusivity of Li+, suppressed the Co dissolution, limited the decomposition of electrolyte and improved the thermal stability of LiCoO2 during cycling.

Co-B alloy with mesoporous structure was firstly synthesized using room-temperature ionic liquids as templates and investigated as an anode for secondary alkaline batteries. Investigations indicate that such mesoporous structure facilitated the electrochemical hydrogen storage. It maintained 94% of the initial capacity (336 mA h/g) after 50 cycles. The excellent cycling performance is most likely due to the stable structure during cycling. Meanwhile, it exhibited an excellent rate capability. The results demonstrated that the prepared Co-B-mesoporous is capable of serving as a high power capability anode for the rechargeable alkaline batteries.