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Developing bifunctional catalysts for the ORR and OER, along with a unique cathode structure, is essential for advancing rechargeable zinc-air batteries (ZABs) and aluminum-air batteries (AABs). Our catalyst (NiFe LDH A-Fe SA Co SA -FeCo Alloy -CNT/NC) integrates nickel-iron layered double hydroxide (NiFe LDH), iron-cobalt dual single atoms (Fe SA Co SA), and iron-cobalt nanoalloy (FeCo Alloy) within carbon nanotubes (CNTs) on a nitrogen-doped carbon framework (NC). Due to its distinctive features, this catalyst excels, achieving an ORR half-wave potential of 0.84 V and an OER potential of 1.56 V (E j=10mAcm −2). In ZABs, it outperforms the Pt/C+RuO 2 , reaching a power density of 266 mWcm−2 and demonstrating impressive rechargeability over 495 h (1484 cycles). Flexible ZABs achieve 173 mWcm−2 and over 270 cycles (90 h), while flexible AABs reach 145 mWcm−2, surpassing Pt/C+RuO 2. Exceptional performance in terms of capacity, power density, rechargeability, and lifespan is attributed to the catalyst's design and the cathode configuration's unique attributes. [Display omitted] • The catalyst was synthesized via Schiff reaction, carbonization and NH 3 processes. • The catalyst shows an excellent bifunctional characteristics of ORR and OER. • The ZAB demonstrates 809 mAh g−1 at 50 mA cm−2 and 266 mW cm−2 at 381 mA cm−2. • The flexible ZAB shows 710.8 mAh g−1 at 1 mA cm−2 and 173 mW cm−2 at 182 mA cm−2. • The flexible AABs reach 120.7 mAh g−1 at 1 mA cm−2 and 145 mW cm−2 at 157 mA cm−2. [ABSTRACT FROM AUTHOR]

Abstract: Turbostratic carbon nanofibers (CNFs) with a rough surface, open pore walls, and a defect structure were continuously produced by the thermal decomposition of alcohol in the presence of an iron catalyst and a sulfur promoter at 1100°C under a nitrogen atmosphere in a vertical chemical vapor deposition reactor. A graphite exfoliation technique using intercalation and thermal shock was employed to expand the graphene layers of the as-produced turbostratic CNFs. The hydrogen storage capacity of the turbostratic CNF samples was measured using the volumetric method with a pressure of up to 1MPa at 77K. The hydrogen storage capacities of the as-produced and exfoliated turbostratic CNFs were 1.5 and 5wt%, respectively. The defects on the surface and expandable graphitic structure are considered important keys to increasing the hydrogen uptake in turbostratic CNFs. [Copyright &y& Elsevier]

Abstract: The fabrication of carbon nanocapsules and carbon nanotubes (CNTs) using an acetylene flame method was investigated. Carbon nanocapsules, a graphitic structure of nanoparticles with a hollow core, were synthesized using catalyst-free acetylene flames while CNTs were formed with the presence of cobalt-based catalysts in addition to acetylene flames. When the synthesis of these materials was carried out, the results showed that a massive amount of high-purity carbon nanocapsules with a particle size in the range of 15–30nm can be produced with the acetylene flame method. The CNTs produced were multi-walled carbon nanotubes measuring a few micrometers in length and 20–30nm in diameter. The acetylene flame method holds great potential for the cost-effective production of CNTs as well as carbon nanocapsules. [Copyright &y& Elsevier]

An 80-cm long tubular carbon coated membrane was fabricated by chemical vapor deposition (CVD) of methane on a multilayered porous ceramic substrate at a temperature of 1000 °C. The deposition of pyrocarbon on the membrane generated a carbon film, the nature of which not only reduced the pore size of the membrane but also changed the physical properties of the membrane, including its hydrophobicity, electrical conductivity, and thermal conductivity. To ensure a uniform deposition of carbon on the membrane, a CVD apparatus equipped with process piping was employed to periodically reverse the direction of the gas flow in the reactor. The CVD experiments were then conducted by varying parameters such as the rate of flow of the gas mixture (methane and nitrogen), the percentage concentration of methane, and so on. To analyze the uniformity of the carbon film, we measured the electrical resistance of the membrane and the permeation of six gases through the sectioned membranes. In the range of our study, it was found that the flow rate of the gas mixture and the alternation of the direction of the gas flow were two important factors for determining the uniformity of the carbon deposit in the membranes. Observation by scanning electron microscope (SEM) and measurement of the nitrogen permeation of the membranes revealed that fabrication of uniform carbon coated ceramic membranes with a desired pore size is possible for applications involving microfiltration, ultrafiltration, and nanofiltration. In addition, the utilization of the superior properties of the membranes such as hydrophobicity and electrical conductivity were suggested for enhancing the degree of separation of the membranes. [Copyright &y& Elsevier]

This study investigates nickel-doped cobalt oxide (Ni-doped Co 3 O 4) nanoparticles as catalysts for the oxygen evolution reaction (OER) in anion exchange membrane water electrolyzers (AEMWEs). Through various characterization techniques, Ni 0.45 Co 2.55 O 4 was identified as exhibiting superior OER activity compared to pristine Co 3 O 4 and other Ni-doped compositions, offering reduced overpotential and higher current density. Density functional theory (DFT) calculations provided mechanistic insights. Evaluation in an AEMWE single-cell setup confirmed Ni 0.45 Co 2.55 O 4 stability and efficiency for hydrogen production. The study underscores the importance of transitioning to renewable sources for hydrogen production and highlights the role of AEMWEs with non-noble metal catalysts in reducing costs. Moreover, it emphasizes the critical influence of the OER on AEMWE performance. Overall, the research demonstrates the potential of Ni-doped Co 3 O 4 nanoparticles as effective catalysts for sustainable hydrogen production, aligning with the goal of achieving 2050 net-zero emissions. • Ni-doped Co 3 O 4 nanoparticles were synthesized by a facile chemical synthesis combined with an annealing treatment. • Density functional theory was employed to predict reduced overpotential for Ni-doped Co 3 O 4 compared to pristine Co 3 O 4. • Ni-doped Co 3 O 4 (Ni x Co 3-x O 4) nanoparticles with particle sizes ranging from 58 nm to 164 nm. • Ni doping affects electron conductivity and cation distribution in Co 3 O 4 catalysts. • MEA with Ni 0.45 Co 2.55 O 4 anode and Pt/C cathode achieved energy efficiency of 69.4% at 300 mA cm−2 and 2.04 V. [ABSTRACT FROM AUTHOR]

Supercapacitors (SC) are essential energy storage devices for renewable energies. In this study, activated microporous carbon spheres (AMCS) and nitrogen-doped AMCS (N-AMCS) were synthesized using a modified extended Stöber method followed by CO 2 activation. A high specific area (>3400 m2 g−1) was obtained for AMCS and N-AMCS, and the diameters of the sphere could be tuned from 400 nm to 1.0 µm. The SC study revealed that the AMCS and N-AMCS achieved specific capacitances of 232.75 and 263.59 F g−1, respectively, in 6 M potassium hydroxide (KOH). The SC pouch cells were filled with aqueous, organic, and ionic liquid electrolytes. In 1 M MeEt 3 NBF 4 in acetonitrile, the energy densities of AMCS and N-AMCS were 27.96 and 31.20 Wh kg−1, respectively, at the current density of 0.5 A g−1, whereas the energy densities of AMCS and N-AMCS were 69.19 and 117.69 Wh kg−1, respectively, in EMIMBF 4. In addition, in the aqueous electrolytes, AMCS and N-AMCS had capacitance retentions of 94% and 97%, respectively, after 10,000 cycles, while the capacitance retentions of 82% and 97% were achieved with AMCS and N-AMCS, respectively, after 50,000 cycles. [Display omitted] • Size-tunable resin spheres were synthesized by the modification of the extension-Stöber method. • The AMCS with a high specific area of 3456.62 m2 g–1 and diameter of 420 nm. • The method provides a simple, cost-effective, environment-friendly and easily scalable process for production. • The pouch cells of AMCS and N-AMCS as the active materials have a good long- term cyclability. [ABSTRACT FROM AUTHOR]

Highlights: [•] Synthesis ZnO thin film by simple method. [•] It can detect a minimum 50ppm NH3. [•] Its operation temperature can lower to 150°C. [•] Change the oxygen conc. to detect the NH3, and try to explain its mechanism. [ABSTRACT FROM AUTHOR]

Lithium-oxygen batteries (LOBs) promise high energy density but suffer from catalyst-related issues. We've developed FeNi-NCNT/DrGO, a novel catalyst, by integrating iron-nickel nanoalloys (FeNi) embedded in nitrogen-doped carbon nanotubes (NCNTs) grafted onto defect-rich reduced graphene oxide (DrGO). The fabrication involved freeze-drying, defect engineering, and thermal treatments. The FeNi nanoalloy within the catalyst demonstrates outstanding bifunctional activity, while the NCNTs serve as an excellent electronic conduction medium and DrGO enables favorable ion transport. The 3D open-space architecture of this catalyst provides a rapid diffusion path for the electrolyte and room for accommodating discharge products. As a result, the LOBs with FeNi-NCNT/DrGO exhibits exceptional electrochemical performance, achieving a deep discharge capacity of 21,153.6 mAh g−1 and a high round-trip efficiency of 98.7% at 200 mA g−1. Moreover, it demonstrates excellent cycling stability, exceeding 100 cycles at 200 mA g−1 with a cut-off capacity of 500 mAh g−1. [Display omitted] • FeNi-NCNT/DrGO was formed by freeze-drying, ball milling, and thermal treatment. • The catalyst shows superior ORR, OER, conductivity, ion diffusion and Li 2 O 2 storage. • LOB with the catalyst shows a capacity of 21153 mAhg−1 and 98.74% efficiency. • LOB exceeds 100 cycles at 200 mA g−1 with a cut-off capacity of 500 mAh g−1. [ABSTRACT FROM AUTHOR]

The inhibitive effects of functional groups originating from the presence of additives on corrosion are linked to the physicochemical and electronic properties of these surficial chemical species. In this work, the acetoxy group (i.e. weak bases) with different orbital characters is integrated with donating/accepting molecules which reveals dissimilar inhibitive behaviour. Introducing cations on the acetoxy groups (-Ac) as additives leads to mitigation of undesirable self-corrosion of the anode. The Al-air battery corresponded to a maximum capacity of 2817 mAhg−1 at 10 mAcm−2 with the use of barium-Ac/KOH electrolyte, demonstrates nearly 95% of the theoretical capacity. However, a capacity of only 2392 mAhg−1 is observed for free additive. In addition, the maximum power density (i.e. 91.32 mWcm−2) increased by nearly 50% with the employment of barium-Ac/KOH. The rechargeable Al–air battery based on barium-Ac/KOH presents a low voltage gap of 0.83 V with a remarkable cyclic stability of 25,000 s. The results show that the acetoxy group integrated with metal ions can be a key player in reducing H 2 evolution rate in the aluminium-air batteries. XPS analysis confirmed an Al-complex (i.e. Al-acetoxy) is formed using barium-ac. DFT calculations confirmed that barium-Ac/KOH provides the minimum value of ΔE (about 5.4 eV), indicating the remarkable ability for reacting with Al+3 ions to adsorb on the anode surface leading to complex (Ba-Ac-Al3+) formation. This study highlights the parasitic corrosion reaction leading to low coulombic efficiency in rechargeable Al- air batteries. • The impacts of additive integrated with acetoxy group was studied on Al corrosion and H2 evolution. • The corrosion inhibition efficiency follows the order of: Ba-acetoxy > Ca-acetoxy > Ethyl-acetoxy. • Ba–Ac/KOH exhibited the optimum discharge capacity 2817 mAh/g and 95% Al utilization. • XPS results revealed a complex containing Al-acetoxy contribute to reduce Al self-corrosion. [ABSTRACT FROM AUTHOR]

Abstract: The ratio of ZnS to AgInS2 is usually adjusted to tune the band gaps of this quaternary (Ag–In–Zn)S semiconductor to increase photocatalytic activity. In this study, the [Zn]/[Ag] ratio was kept constant. The hydrogen production rate was enhanced by increasing the content of indium sulfide. Compared to the steady H2 evolution rate obtained with equal moles of indium and silver ([In]/[Ag] = 1, 0.64 L/m2 h), that obtained with In-rich photocatalyst ([In]/[Ag] = 2, 3.75 L/m2 h) is over 5.86 times higher. The number of nanostep structures, on which the Pt cocatalysts were loaded by photodeposition, increased with the content of indium. The indium-rich samples did not induce phase separation between Ag x In x Zn y S2x+y and AgIn5S8, instead forming a single-phase solid solution. Although the photocatalytic activity decreased slightly for bare In-rich photocatalysts, Pt loading played a critical role in the hydrogen production rate. This study demonstrates the significant effect of In2S3 on this unique (Ag–In–Zn)S photocatalyst. [Copyright &y& Elsevier]

Abstract: Hydroxyapatite (HA, Ca10(PO4)6(OH)2) nanoparticles were synthesized using calcining calcium dihydrogenphosphate (Ca(H2PO4)2 ·H2O), calcium hydroxide (Ca(OH)2), and polyethylene glycol (PEG) at 900 °C in an oxygen atmosphere. This one-step process yields HA nanoparticles with similar particle sizes (e.g., 50–80 nm) that are well-crystallized and non-aggregated. PEG is an important factor in controlling the particle size, crystal phase, and degree of aggregation in these HA particles. This conclusion is supported by results from a field-emission scanning electron microscope (FE-SEM), X-ray diffractometry (XRD), energy dispersive X-ray analysis (EDS), a high-resolution transmission electron microscope (HR-TEM), and dynamic light scattering (DLS). [Copyright &y& Elsevier]

Abstract: Platelet graphite nanofibers (PGNFs) were synthesized by thermal decomposition from a mixture containing polymer and catalyst. The hydrogen storage capacity of the material was measured using the volumetric method carried out at 298K at a pressure up to 4.83MPa. The results show that the PGNF possess a 3.3wt.% hydrogen storage capacity. The gaseous molecules were adsorbed between two graphene planes in the PGNFs and residual amounts of hydrogen were possession within PGNFs while pressure decreased to ambient conditions. X-ray diffraction was used to understand the PGNF structural modifications before and after hydrogen uptake. We found that the PGNF interlayer undergoes expansion and returns back to the initial value before and after hydrogen uptake. [Copyright &y& Elsevier]

[Display omitted] Carbon quantum dots (CQDs) with an average diameter of 3 nm, exhibiting blue photoluminescence, have been obtained from commercial conductive carbon black by a cost-effective and straightforward exfoliation method using dry ball milling in the presence of sodium carbonate. As a secondary abrasive medium, sodium carbonate provides effective exfoliation of carbon black with a high degree of CQD graphitization and plays an essential role in the functionalization of CQDs with oxygen groups. Due to the low toxicity of CQDs against HeLa cancer cells (cell viability above 90% at a CQD concentration of 200 μg cm−3) and the ability to penetrate cells and emit blue light, CQDs are possibly suitable for biological imaging of cells. [ABSTRACT FROM AUTHOR]

Urchin-like α-Fe 2 O 3 microspheres (radial α-Fe 2 O 3 nanowires on α-Fe 2 O 3 microspheres) are used as field emitters for a flat-panel lighting device with a lateral-gate-electrode structure. The urchin-like α-Fe 2 O 3 microspheres are in situ grown on the cathode electrode via thermal oxidation at 350 °C for 12 h after the screen-printing of pattern Fe microspheres on the cathode electrode. The lateral-gate triode structure comprises an Ag cathode and a pair of Ag gate electrodes screen-printed laterally on both sides of the cathode. The role of the gate electrodes is to enhance the emission current and increase luminance uniformity and that of the anode electrode is to control the luminance intensity. The radial nanowire emitters on the spheres ensure good field emission performance without any pretreatment and in situ growth of the material enhances the contact between the electrode and the material. The microspheric emitters and the lateral-gate structure, which covers a small part (4.32%) of the printed area over the entire panel (3.5 cm × 5 cm) leads to, high luminance, excellent luminance uniformity and tunable luminance characteristics of the field-emission light source. A maximum luminance of 8330 cd/m 2 and a luminance uniformity of 92.4% are achieved with a gate voltage of 500 V, an anode voltage of 4000 V, and the anode current of 1.32 mA. [ABSTRACT FROM AUTHOR]

Aqueous rechargeable Zn-ion batteries (ARZIB) are promising candidates for next-generation batteries because of their high safety, low cost, and relatively high capacity. In this study, we developed hydrated and potassium-doped manganese dioxide (MO) nanowires mixed with carbon nanotubes (CNT) on a graphene substrate (hydrated KMO-CNT/graphene) for ARZIB. A simple polyol process using poly(ethyl glycol), KMnO 4 , CNT, and graphene was utilized to fabricate hydrated KMO-CNT/graphene. MnO 2 nanowires with diameters of 15–25 nm possess a high specific capacity with a short diffusion path. The intercalated K ions and hydrates in the layered MnO 2 nanowires maintained the MO structure during the charge and discharge processes, whereas carbon nanomaterials (CNT and graphene) enhanced the conductivity of the material. Consequently, hydrated KMO-CNT/graphene demonstrated good ARZIB performance. A high capacity of 359.8 mAh g–1 at 0.1 A g–1, and at a high current density of 3.0 A g–1, a capacity of 129 mAh g–1 with 77% retention after 1000 cycles, were achieved. • Hydrated and potassium-doped MnO 2 mixed with CNT on graphene substrate is synthesized. • Polyol process was conducted with PEG, KMnO 4 , CNT and graphene. • MnO 2 has a high capacity, intercalated K and H 2 O keep the structure of MnO 2 and CNT/graphene provide conductivity. • The hydrated KMO-CNT/graphene delivers high specific capacities of 359.8 mAh g–1 at 0.1 A g–1 and 129 mAh g–1 at 3.0 A g–1 with 77% retention. • The performance of ZIB reaches a high energy density of 410.36 Wh kg–1 at 109.93 W kg–1. [ABSTRACT FROM AUTHOR]

Graphene quantum dots (GQDs) were formed by liquid-phase exfoliation in an ultrasonic bath using platelet graphite nanofibers (PGNFs) as the raw material and dimethyl sulfoxide (DMSO) as the exfoliation agent. PGNFs, carbon fibers with graphene nanosheets stacked perpendicular along the fiber axis, were sectioned layer by DMSO for 3 h with ultrasonic assistance to create GQDs. The diameters of the derived GQDs were in the range of 10–30 nm and fewer than five graphene layers were formed. X-ray photoelectron spectroscopy analysis revealed that no functional groups were grafted onto the GQDs during the process, indicating that the synthetic route produced high-quality GQDs. [ABSTRACT FROM AUTHOR]

[Display omitted] • The novel CNT-CoFe/NC and CNT-CoS 2 Fe/NC was fabricated by thermal treatments and vulcanization. • CNT-CoFe/NC shows a better ORR performance than Pt/C while CNT-CoS 2 Fe/NC shows a better OER performance than RuO 2. • The hybrid catalysts, CNT-CoFe/NC + CNT-CoS 2 Fe/NC, demonstrate a superior performance of rechargeable Zn-air battery. Catalysts with embedded and functionalized elements used for the effective control of oxygen-reduction (ORRs) and oxygen-evolution reactions (OERs) are the key to developing high-performance rechargeable Zn–air batteries (ZABs). Here, carbon nanotube-grafted, Co–Fe embedded, nitrogen-doped porous carbon nano-frameworks (CNT–Co–Fe/NC) were synthesized through the carbonization of Fe-doped zeolitic imidazolate frameworks and vulcanization of the CNT–Co–Fe/NC to form CNT–CoS 2 –Fe/NC. The CNT–CoS 2 –Fe/NC exhibited a superior OER performance with an overpotential of only 1.637 mV at a current density of 10 mA/cm2 and a Tafel slope of 197 mV/dec (which, for RuO 2 , is 112 mV/dec), whereas the CNT–Co–Fe/NC showed an excellent ORR performance with a Tafel slope of 71 mV/dec (which, for 20 wt% Pt/C, is 91 mV/dec). A ZAB was developed with a hybrid catalyst of 50 wt% CNT–Co–Fe/NC and 50 wt% CNT–CoS 2 –Fe/NC in the cathode, and it achieved an excellent specific discharge capacity of 814 mAh/g at 50 mA/cm2, high power density of 245 mW/cm2, and outstanding cycle stability of over 1800 cycles (300 h) at 10 mA/cm2 with a very high retention of 95% and small potential gap of 0.68 V, compared to the corresponding values of 803.7 mAh/g, 215.3 mW/cm2, 900 cycles: retention 92%, and potential gap 0.837 V for 150 h for the ZAB with a hybrid catalyst of Pt/C + RuO 2. It is hypothesized that the ZAB with the novel hybrid catalyst exhibits its excellent catalytic activity and durability as a result of the synergistic effect of the catalyst's embedded heteroatoms and nitrogen–metal/carbon framework that enhances the ORR/OER performance, porous carbon nano-framework that enables rapid diffusion and electrical conduction, and carbon nanotubes that complete the external electrical connection between the catalysts. [ABSTRACT FROM AUTHOR]

• Development of lithium metal based anode through novel Semi-infusion technique. • Ni mesh to be act as a host material to accommodate li ions during stripping/plating. • The symmetrical Li/SnO 2 -Ni cell revealed a low voltage gap of ∼ 8 mV over 2000 h at 1 mA cmˉ2 and 1 mAh cmˉ2. • Full cell cycling performance of the Li/SnO 2 -Ni with LFP delivered a specific capacity of 170 mAh gˉ1 with an excellent stability. Lithium metal battery is a promising candidate for the next generation batteries due to its high theoretical specific capacity and energy density. However, the dendritic propensity of Li metal and inevitable volume variation are critical obstacles for commercialization. Here, we prepare a novel anode that Li infused partially into the tin oxide coated Ni mesh (Li/SnO 2 -Ni) by semi-infusion strategy. The strategy can provide an adequate but not excessive amount of Li in the host for the battery. The SnO 2 -Ni mesh abates the dendritic formation and volume variation due to its lithiophilic property, three-dimensional (3-D) structure, and excellent conductivity guiding the Li-ion deposition and stripping uniformly during cycling. As a result, Li/SnO 2 -Ni cell can cycle a long span with an exceptionally low voltage gap of 8, 15, and 200 mV at a different current density and of 1, 3, and 35 mA cm−2, and a capacity of 1, 1 and 5 mAh cm−2, respectively, in a symmetrical cell. The performance of full cell against LiFePO 4 cathode achieves a superior capacity of 173 mAh g−1 at 0.2 C and the retention of 90 % after 70 cycles. This work offers a facile and effective strategy to fabricate a 3-D composite anode and promotes the practical applications of Li metal batteries. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: A double-sided surface light source based on field emission (FE) using an alternating current power source is demonstrated. Carbon-nanotube (CNT) emitters and ZnS phosphor are mixed and screen-printed onto two pieces of indium tin oxide glass that were assembled together with the coated surfaces facing each other to make a parallel-plate, diode-structure FE device. The device has a double-sided luminance distribution with a turn-on field of 2V/μm, a good uniformity, and a stable luminance of 4000cd/m2. The results show that CNTs not only act as good field emitters but also as an electrically conductive network around the isolated phosphors. The network prevents electric arcing and thus extends the lifetime of the device. [Copyright &y& Elsevier]

Abstract: Thin-walled carbon nanotubes (TWCNTs) were synthesized using a zirconium (Zr) plate by cold-wall chemical vapor deposition of a mixture gas consisting of C2H2 and H2 under a pressure of 1.20torr. The Zr plate was used for the formation of Zr nanocatalysts during the thermal process and used as substrate to eliminate the effects of interactions between catalyst and substrate during CNT synthesis. The TWCNTs were 4–9nm in diameter and a few micrometers long. Nanometer-sized defects on the Zr bulk material may have a low melting temperature, allowing them to form droplet-like catalysts and achieve high carbon solubility for the formation of CNTs. [Copyright &y& Elsevier]

Abstract: The combination of porous carbon nanofiber (PCNF) and room-temperature ionic liquid (RTIL) provided a suitable microenvironment for heme-proteins to transfer electron directly. Hemoglobin, myoglobin, and cytochrome c incorporated in PCNF/RTIL films exhibited a pair of well-defined, quasi-reversible cyclic voltammetric peaks at about −0.28V vs. SCE in pH 7.0 buffers, respectively, characteristic of the protein heme Fe(III)/Fe(II) redox couples. The cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the modified electrode. The heme/PCNF/RTIL/CHIT films were also characterized by UV–vis spectroscopy, indicating that heme-proteins in the composite film could retain its native structure. Oxygen, hydrogen peroxide, and nitrite were catalytically reduced at the heme/PCNF/RTIL/CHIT film modified electrodes, showing the potential applicability of the films as the new type of biosensors or bioreactors based on direct electrochemistry of the redox proteins. [Copyright &y& Elsevier]

Abstract: The 3D mesoporous, well crystalline RuO2 film prepared via the evaporation-induced self-assembled method (EISA) successfully demonstrates the extremely high power performances (e.g., excellent capacitive behavior at 10,000mVs−1, ultrahigh-frequency capacitive responses (the absence of a knee point in the Nyquist plot), and 2.6MWkg−1 with an acceptable energy density of 4.6Whkg−1). These excellent capacitive performances were identified by means of voltammetric and electrochemical impedance spectroscopic (EIS) analyses. The mesoporous (with mean pore spacing of 18.1nm) and crystalline nature of this film was characterized by means of the field emission scanning electron microscopy (FE-SEM), Brunaur–Emmett–Teller (BET) method, small-angle X-ray scattering (SAXRS), high-resolution transmission electron microscopy (HR-TEM), electron diffraction (ED), and X-ray diffraction (XRD) analyses. This mesoporous, well crystalline RuO2 film constrains the redox transition to the superficial region meanwhile the tailored mesoporous structure increases the electrochemically active centers, promotes the penetration of electrolytes, provides the “proton reservoirs”, and enhances the rate of electron transport simultaneously for the ultrahigh power application. The specific capacitance of this mesoporous RuO2 can be enhanced from 84 to 185Fg−1 after the microwave-assisted hydrothermal treatment. [Copyright &y& Elsevier]

Abstract: High-purity carbon spheres were continuously produced by pyrolysis of acetylene at 1000 °C under a nitrogen atmosphere in a vertical chemical vapor deposition reactor. The produced carbon spheres had diameters in the range of 200–500 nm and were perfectly spherical in shape with rough surfaces. High resolution transmission electron microscopy analysis revealed that the carbon spheres were constructed of heavily distorted graphene layers. The results of the X-ray diffraction pattern and Raman spectra also confirmed that the presence of disordered graphene layers was due to a low graphitization degree. In addition, thermal stability and thermal oxidation of carbon spheres were studied. The results found that the surface of the carbon spheres could be modified and the amount of oxygen-containing functional groups increased after oxidation. In summary, the method provided a catalyst-free, substrate-free, hydrogen-free, and cost-effective synthesis for continuous production of carbon spheres. [Copyright &y& Elsevier]

Abstract: Turbostratic carbon nanofibers (CNFs), platelet graphite nanofibers (PGNFs) and tubular graphite nanofibers (TGNFs, also called multi-walled carbon nanotubes) were synthesized using thermal decomposition from a mixture of poly(ethylene glycol) and NiCl2. A detailed study found that the synthesis temperature dramatically affected the morphology and topography of the catalysts, which play an important role in the synthesis of the various CNFs. At the temperature of 600°C, irregular shape nanocatalysts with very rough surfaces were formed for the synthesis of turbostratic CNFs. Cubic-like nanocatalysts were formed at 750°C for PGNFs and truncated cone-like nanocatalysts were formed at 850°C for TGNFs. The surface roughness and the shape of the catalysts determined the stacking order of the graphene layers so that different types of CNF were formed. The growth direction of the graphene layers was from the Ni(111) plane for PGNFs and from the Ni(110) plane for TGNFs. Characterizations and field emission properties of these materials were also studied and compared. [Copyright &y& Elsevier]