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Electrochemical synthesis of hydrogen peroxide (H 2 O 2) via oxygen reduction reactions (ORR) represents a green, environmentally friendly, and decentralized alternative to the conventional, fossil-based, and centralized anthraquinone process. This work presents a flow-through module using commercial carbon black (CB) as a catalyst at current densities of up to 120 mA cm−2. Acid treatment of CB increases its oxygen content, leading to Faraday efficiency (FE) values above 80 % with a maximum specific H 2 O 2 production rate of 64.3 mg cm−2 h−1. Additionally, the effect of catalyst loading on the functionality of a gas diffusion electrode (GDE) at 120 mA cm−2 and over long-term electrolysis (7.5 h) is investigated, discussing the detrimental penetration of electrolyte into the GDE due to the enhanced electro-wetting, which shifts the three-phase boundary toward the gas channel side. This study underscores the critical significance of optimizing the parameters involved in GDE fabrication, especially under high current densities and extended operational periods, propelling our understanding toward the development of a robust flow-through module for the electro-generation of H 2 O 2. [Display omitted] • Oxygen-doped commercial carbon black selectively catalyzes H 2 O 2 electrosynthesis. • Faraday efficiencies (FE) above 80% for current densities up to 120 mA/cm2. • Insights into GDE flooding and its detrimental impact on FE and H 2 O 2 production. • Electro-generation of H 2 O 2 in a flow-through module up to 1.5 wt% [ABSTRACT FROM AUTHOR]

• Cobalt phthalocyanine (CoPC) is dispersed on carbon black with different methods. • The dispersed materials are pyrolyzed under argon at various temperatures up to 900 °C. • CO faradaic efficiency remained > 45 % post-pyrolysis when catalyst loading > 7.9 wt%. • Spectroscopy (EXAFS) shows that the nature of the pyrolyzed material depends on CoPC loading. • Precursor crystallinity is a critical factor in the reactivity after pyrolysis. Understanding the structure-activity relationship of materials that are active for the CO 2 electrochemical reduction reaction (CO 2 ERR) is crucial for developing stable, high-performance catalysts. In this research, it is first shown that ball-milling is a highly efficient way to disperse cobalt phthalocyanine (CoPC) onto carbon black without influencing the CO 2 electroreduction performance of the resulting materials. Then, the link between the loadings of the CoPC precursor on the carbon support and the CO 2 ERR activity of the pyrolyzed materials is demonstrated. With CO current efficiencies higher than 45% and CO current densities as high as -20 mA cm−2 at -0.77 V vs. RHE, the materials with CoPC loadings of 7.9 wt% and higher were still surprisingly active after pyrolysis at 800 and 900 °C. On the other hand, the CO 2 ERR activity of the materials containing less than 6.1 wt% CoPC was drastically reduced after pyrolysis at these temperatures, with CO current efficiencies lower than 10 %. X-ray powder diffraction revealed that only the materials containing crystalline CoPC before pyrolysis showed good CO 2 ERR activity after pyrolysis at 800 and 900 °C. Furthermore, X-ray absorption spectroscopy showed that the loading of the CoPC precursor influenced the structure of the active sites in the pyrolyzed CoPC/C materials. Overall, this study highlights the importance of the dispersion of CoPC when forming a material that is catalytically active for CO 2 ERR after pyrolysis. [ABSTRACT FROM AUTHOR]

• Tunable oxygen reduction reaction properties is achieved by varying the electrolyte pH. • An A3B-type cobalt porphyrin-coated carbon black is designed as the catalyst. • Five electrolytes with pH values spanning from 0.7 to 13.7 are studied. • The composite exhibits the most positive potentials and the lowest Tafel slope at pH13.7. • Poor activity but high selectivity for 4-electron ORR is obtained at pH3.7. Understanding the pH-dependent mechanism of metalloporphyrin-based composite electrocatalystic oxygen reduction reactions (ORRs) can provide the basis for rational porphyrin molecular design. Tunable ORR properties of a cobalt porphyrin-based composite catalyst aFP-TCoP/C is accomplished by adjusting the electrolyte pH values spanning from 0.7 to 13.7. The composite performs the best ORR reactivity in the pH13.7 electrolyte, exhibiting the most positive characterized potentials (the ORR reduction potential E ORR of 0.76 V and the half-wave potential E 1/2 of 0.80 V) and the smallest Tafel slope of 43.1 mV dec−1. Whilst the sample with the pH3.7 electrolyte displays quite negative reduction potentials and a large Tafel slope, it exhibits an electron transfer number of 3.84, which indicates a nearly 4-electron transfer selectivity. The findings provide a practical protocol for regulating the catalytic reactivity and selectivity of ORRs by adjusting the components of electrolytes. [Display omitted] [ABSTRACT FROM AUTHOR]

Here, we report the investigation of carbon black as a cost-effective nanomodifier of thermoplastic polyurethane-based 3D printed electrodes for enhancing their electrochemical performances. The sensor was produced by scratching the working electrode with sandpaper, followed by the deposition of carbon black dispersion by drop casting. The morphological characterisation was carried out, showing the presence of a homogeneous coating of carbon black with a typical rough and spongy structure. Additionally, the electrochemical characterisation using electrochemical impedance spectroscopy highlighted the advantage of using carbon black as a nanomodifier of the working electrode surface after printing by obtaining the resistance of charge transfer equal to 327 ± 43 kΩ and 1.45 ± 0.06 kΩ for bare electrode and carbon black-modified electrode, respectively. When tested in cyclic voltammetry using ferro/ferricyanide, uric acid, dopamine, ascorbic acid, and free chlorine as target electroactive compounds, we demonstrated that the presence of carbon black cast onto the working electrode surface transformed the electrode from non-responsive to responsive electroanalytical tool. The analytical features of the developed responsive sensor were assessed for the detection of free chlorine in tap water with a linearity of 0.2–20 ppm and a limit of detection equal to 0.01 ppm. The accuracy was evaluated by spiking tap water samples with free chlorine concentrations equal to 0.5, 1, and 5 ppm, obtaining recovery percentages of (103 ± 2)%, (104 ± 3)%, and (95 ± 3)%, respectively. Additionally, the sustainability (electro)chemical-free pre-treatment thermoplastic polyurethane-based 3D printed electrodes modified with carbon black were evaluated by the White Analytical Chemistry principles. The advantages of 3D printed sensors modified with carbon black by drop casting were demonstrated, in terms of both the electrochemical performances and sustainable aspect, enlarging the use of carbon black as a nanomodifier to the 3D printed electrodes, beyond the 2D printed electrodes. [Display omitted] [ABSTRACT FROM AUTHOR]

Modifying stainless steel (SS) surfaces with biocompatible materials is a practical approach to making SS an efficient electrode material for microbial electrochemical systems (MESs). However, a simple, cost-effective method to modify large-size SS is still missing. Here, we proposed to use spray coating to modify SS mesh (SSM) with acetylene black (AB) nanoparticles to make SSM an efficient anode material for MESs. The SEM images and Raman spectrum confirmed that AB nanoparticles could be uniformly coated onto the surface of SSM. The AB nanoparticles dramatically increased the specific surface area and biocompatibility of SSM. Consequently, when tested as the anode in MESs, the AB-coated SSM exhibited excellent biofilm formation ability, while the bare SSM saw inferior biofilm formation potential. Moreover, the current density achieved on the AB-coated SSM (1.95 ± 0.1 mA/cm2) was orders of magnitudes higher than that achieved on the bare SSM (0.01 ± 0.01 mA/cm2). Compared to other surface modification methods for SS, spray coating is simple, cost-effective, and most importantly readily for large-size SS electrodes. Therefore, spray coating of carbon nanoparticles holds excellent potential for scaling up SS electrodes for MESs. [Display omitted] [ABSTRACT FROM AUTHOR]

• A Box-Behnken design for graphite anodes slurries optimization was presented to highlight the importance of the component's interactions to obtained higher performed anodes of lithium-ion batteries customization. • The carbon black content is the most significant effect in both materials which is reflected in higher capacities and coulombic efficiencies. • For the overall behavior, the binder/carbon black interactions are relevant in terms not only of electrochemical performance but also in the obtention of more homogeneous and better adhesion anodes. The technological application of lithium-ion batteries (LIB) grows constantly, making customization of the batteries a current necessity and sometimes a challenge. In this paper we described carbon-slurry optimization process for anodes of lithium-ion batteries customization by using a surface response statistical experiment with four response variables such specific discharge capacity, coulombic efficiency, anodes mass deviation, and capacity retention. We studied two commercial graphite active materials by characterizing the materials via Raman spectroscopy, SEM, and electrochemical techniques. We corroborate the graphite structure for both materials but with morphological differences such as shape and particle size. The binder composition seems to interfere with the active carbon materials capabilities while it generates better performance for one of them. Although the chemical structure of both materials was confirmed to be the same via Raman experiments, SEM images shows critical morphological differences that interferes with the final slurry thus, affecting the electrochemical performance of the anodes. Further studies are required to understand ECSA and its possible effect on the charge/discharge capacities of the anodes. [Display omitted] [ABSTRACT FROM AUTHOR]

• New insights on the reaction mechanism of Cu 2 Se with carbon-modified separator. • Altering the reaction mechanism of Cu 2 Se from bulk diffusion to surface capacitive. • The Cu 2 Se with carbon-modified separator delivers 95 mAh g −1 over 5000 cycles. • A promising strategy for the practical application of Cu 2 Se in aluminum batteries. Transition metal selenides (TMSs) become one of the most promising cathode materials for rechargeable aluminum batteries (RABs) due to the advantages of high specific capacity, low cost, and simple preparation process. However, TMSs are soluble in the acidic chloroaluminate ionic liquid electrolyte during cycling, leading to undesirable electrochemical performance. Herein, rechargeable Al-Cu 2 Se batteries are fabricated with acetylene black modified separator (AB/GF/A) showing excellent electrochemical performance with capacity retention of 95 mAh g−1 after 5000 cycles at 0.5 A g−1 and 166.1 mAh g−1 at 1.0 A g−1. By combining electrochemical tests and ex situ spectroscopy and electronic microscope characterizations, it is revealed that the dissolved Cu and Se species adsorbed on the surface of AB/GF/A still remain electroactivity, which transforms the diffusion-controlled mechanism of Cu 2 Se to surface pseudocapacitance-controlled behavior, thus suppressing the shuttle effects and boosting the reaction kinetics. The in-depth understanding of the functionalized separator in energy storage mechanism of TMSs could provide reference for further progress of RABs in the future work. Adopting carbon-modified separator in rechargeable aluminum batteries suppresses shuttle effect and alters the reaction mechanism of Cu 2 Se from bulk diffusion to surface capacitive, enabling long cycling life and fast reaction kinetics. [Display omitted] [ABSTRACT FROM AUTHOR]

The development of efficient and cost-effective water splitting electrolyzers is a fundamental step to support the achievement of climate neutrality by using renewable energy sources to produce green H 2 as a form of clean fuel. In this work, we investigated Pt-based nanostructured cathodes for high-performance alkaline electrolyzers (AELs), showing the beneficial effect of graphene over traditional carbon black as nanocatalysts support. By relying on a water-based, scalable, synthetic method, surface-cleaned Pt nanoparticles were successfully produced and strongly anchored to defect-free graphene flakes, the latter produced through wet-jet milling exfoliation of natural graphite. Once deposited on conventional gas diffusion layers, Pt/graphene catalysts outperform traditional Pt on Vulcan (Pt/C) in terms of hydrogen evolution reaction (HER) activity and performance durability. The two-dimensional morphology of graphene flakes strongly retains the catalysts in the electrode even in the absence of any binder, while intrinsically ensuring the exposure of the catalytic sites for the HER. This rationale enables the fabrication of high-performance AELs based on Pt/graphene cathodes. By using commercially available cost-effective anodes (stainless-steel meshes), our AELs reached current densities of 1 A cm−2 at a voltage of as low as 1.71 V. These AELs can even operate up to more than 2 A cm−2 (e.g., 2.2 A cm−2 at 1.90 V), with stable performance during accelerated stress tests. Our study discloses two main aspects: (1) graphene is an effective conductive support for 1–10 nm-scale catalysts for the development of nanostructured cathodes with elevated catalytic properties and durable performance; (2) the use of efficient nanostructured cathodes can boost the AEL's performance to state-of-the-art values reported for proton-exchange membrane electrolyzers, avoiding the use of expensive anodes (e.g., Ir-based ones). [ABSTRACT FROM AUTHOR]

This work presents a comprehensive analysis of the impact of carbon nanotubes (CNT) and carbon nanofibers (CNF) composition on the performance of nano-Si anodes in lithium-ion batteries. The nano-Si anode suffers from chemo-mechanical issues caused by its large volumetric change (e.g., 280%) during cycling. One of the promising solutions in electrode level is to establish a robust electronic conduction pathway in Si anodes by incorporating CNT and CNF with high aspect ratios. The objective of this work is to quantitatively measure the performance improvement achieved by CNT and CNF based on their compositions and analyze the improvement mechanism through electrochemical methods. The results indicate that substituting a portion of carbon black with CNT and CNF in a range of 1 – 10 wt% can enhance the capacity retention (from 44% to around 60%) and the fast-charging and fast-discharging capabilities. Electrochemical impedance spectroscopy (EIS) and distribution of relaxation times (DRT) analyses revealed that 5% – 10% CNT and CNF conductors effectively suppressed contact impedances growths in Si anodes. In summary, our findings highlight the importance of precise control over the composition of CNT and CNF to achieve good electrode morphology and electrochemical properties for nano-Si anodes. [ABSTRACT FROM AUTHOR]

• Gold nanoparticle (AuNPs) functionalized ultra low-cost carbon black (CB) modified electrode was prepared. • Intrinsic Ni in the CB was utilized as a precursor for in-situ AunPs formation via alloy-like complex formation. • Highly efficient hydrazine-electrocatalytic oxidation was observed. • SECM technique was adopted for imaging of the surface-morphology. • Electroanalytical performance of the CB@AuNPs was explored. Gold nanoparticles (AuNPs) anchored carbon-nanomaterial chemically modified electrodes have been widely used for electrocatalytic applications. Indeed, only a fraction of AuNPs surface is found to be active, while most of the surface is inactive in nature. Thus, it is a challenging research to prepare active AuNPs suitable for electrocatalytic applications. Herein, we present a low-cost intrinsic nickel-containing carbon black (CB-Ni int , int= intrinsic nickel) modified glassy carbon electrode as an efficient matrix for forming highly active AuNPs (GCE/CB-Ni int @AuNPs). Specific electrocatalytic oxidation of hydrazine has been used as a model system to compare the active sites of the AuNPs. Various carbon nanomaterials like SWCNT, MWCNT, carbon nanofiber, and graphite nanopower-modified electrodes and externally deposited Ni (Ni ext) on the carbon-modified electrodes were examined as controls for the AuNPs formation and hydrazine electrocatalytic activity. Amongst all, the CB-Ni int matrix-modified electrode has shown the best electrocatalytic activity. The GCE/CB-Ni int @AuNPs was subjected to various physicochemical characterizations like FESEM, TEM, Raman, IR, XPS, and scanning electrochemical microscopy (SECM) using a Eu3+/2+ redox probe. Meanwhile, with Fe(CN) 6 3−, ex-situ derivatization of Ni ext as Ni-hexacyanoferrate, CB@Ni ext -HCF, was specifically inferred. It has been revealed that AuNPs form an intrinsic Au-Ni int alloy system on the interstitial position of CB-Ni int. On the other hand, a bulk layer-like AuNPs morphology was observed with the CB-Ni ext modified electrode case. This unique structural feature of the CB-Ni int @AuNPs sets a new trend in AuNPs-based chemically modified electrode preparation and electrochemical applications. As a proof of concept, selective electrochemical sensor application of hydrazine with a current sensitivity of 4.37 mA mM−1 cm−2, which is about 5-10 times higher than the majority of the conventional AuNPs-modified electrodes, without any common interference from H 2 O 2 , uric acid, ascorbic acid, dopamine, and cysteine, was demonstrated. [Display omitted] [ABSTRACT FROM AUTHOR]

• Development of flexible nanocellulose-based carbon black@polyaniline electrodes. • Enhancement of the specific capacity and cycling stability by nanostructuring of PANI. • Green and cost-effective way to prepare high-performance pseudocapacitive electrode. Flexible, lightweight and electrically conductive composites based on renewable resources have recently attracted a growing interest for the development of high performance sustainable energy storage devices that can meet the needs of modern wearable and portable electronics. Herein, we developed a high performance carbon black@polyaniline (PANI) based flexible electrodes using a facile, low cost and environmentally friendly strategy. The strategy consisted of a co-deposition and nanostructuring of PANI layer with tailored morphology on the surface of carbon black and nanofibrillated cellulose (NFC) via in situ polymerization. NFC acted as a mechanical skeleton and imparted the electrode with strength and flexibility to ensure excellent electrochemical performance. The co-doping of PANI chains via a combination of a primary/secondary dopant, namely, HCl/poly(2-acrylamido-2-methyl-1-propanesulfonic acid), was used to control the morphology of PANI. Correlation between the textural properties of the carbon black, NFC loading, and the properties of the resulting electrodes was established. The maximum specific capacitance of 363±9 F/g at the potential scan rate of 50 mV/s was exhibited by the electrode with 60% of active material loading, for which an effective growth of hierarchical nanostructures of carbon black@PANI on the surface of NFC was achieved, leading to the highest specific surface area of the composite (861 m2/g) and a to a microporosity/mesoporosity balance. The remarkable cycling stability of the hybrid electrodes was attained as the specific capacitance retention was close to 100% with a negligible capacity decay within the tested period (over 500 cycles) regardless of the amount of the active material. This study provides an eco-friendly and cost-effective way to prepare high performance flexible electrodes for pseudo-capacitors [Display omitted] [ABSTRACT FROM AUTHOR]

High-performance supercapacitors are widely studied, but few works have paid attention to the optimization of conductive bonding networks in the electrode to improve its electrochemical performance. Herein, a rationally designed three-dimensional (3D) conductive bonding network consisting of one-dimensional carboxylated carbon nanotubes (CNT-COOH) and two-dimensional reduced holey graphene oxide (rHGO) is introduced to porous carbon nanofiber/ultra-thin MnO 2 nanosheets (PCNF/U-MnO 2) electrode through vacuum filtration. The CNT-COOH/rHGO network endows the electrode with desired electron transport and ion diffusion properties for its advantages in 3D structures, conductivity and electrolyte wettability, which promote efficient use of PCNF/U-MnO 2 active materials. Thus, PCNF/U-MnO 2 in the electrode with CNT-COOH/rHGO network shows better capacitive performance than that of traditionally fabricated electrode with PTFE and acetylene black. Besides, CNT-COOH/rHGO network is conducive to structural stability of PCNF/U-MnO 2 electrode, and it obtains a capacitance retention of 87% even after 4500 cycles. Then, an asymmetric supercapacitor with PCNF/U-MnO 2 cathode and N, B-doped PCNFs anode has been assembled, which exhibits good flexibility using LiCl/PVA hydrogel as electrolyte and has a high energy density of 45 Wh kg−1 at a power density of 540.8 W kg−1. The strategy of CNT-COOH/rHGO network construction can be an effective and promising way beneficial to high-performance supercapacitor fabrication. [Display omitted] [ABSTRACT FROM AUTHOR]

This work aims at better understanding the interactions existing between the liquid electrolyte and the solid composite electrode in a Li-ion battery. We substituted the common active material (e.g. LiNi 1/3 Mn 1/3 Co 1/3 O 2 or LiFePO 4) by an insulating (inactive) γ-Al 2 O 3 compound in order to detect and evidence the interaction between the carbon black electronic additive and the liquid electrolyte. Our study presents the characterization of charge (electrons and ions) transport at different scales by combining a high-frequency analysis performed by broadband dielectric spectroscopy (BDS, up to 1010 Hz), along with a low-frequency analysis performed by electrochemical impedance spectroscopy (EIS, down to 10−3 Hz). Two carbon black materials with two different specific surface areas (80 m2.g−1 and 65 m2.g−1, respectively) were studied. The electronic percolation threshold and the kinetics of impregnation of the hierarchical composite electrode by the liquid electrolyte have been determined with respect to the carbon black content. The significant influence of the adsorbtion of ions at the carbon black surface on the electrons transport is particularly highlighted and explained. [ABSTRACT FROM AUTHOR]

• Hybrid nanoparticles can improve the conductivity in NR nanocomposites. • Piezoresistivity and piezoimpedance have linear trend in higher conductivities. • Impedance spectroscopy gives versatility to strain sensing measurements. • Piezo-capacitance has better sensitivity than piezoresistivity in solvent sensing. In this work, natural rubber nanocomposites filled with carbon black and carbon nanotubes were prepared via latex mixing, and their applicability as multisensory devices were analyzed through Electrochemical Impedance Spectroscopy (EIS). Static and cyclic strain sensing was performed until 300% strain and the piezoresistivity, piezo-impedance, and piezo-capacitance were evaluated. The results indicated that impedance magnitude could be used instead of calculated resistivity, especially in lower and medium strain ranges. In higher strains, the capacitive behavior turns predominant, and the piezo-capacitance becomes the ideal parameter to be measured providing higher sensitivities as the gage factor (GF) reaches ∼41.82 in 300% strain. The solvent sensing also showed that piezo-capacitance is a better measure than piezo-impedance, with a quicker response time and greater sensibility. This study demonstrated that using EIS in strain and solvent sensing of rubber nanocomposites can offer more detailed information about complex transport mechanisms and improve the sensitivity, linearity, and response time of elastomeric sensors. [ABSTRACT FROM AUTHOR]

• Facile vacuum-assisted filtration method was used to assemble ERGO/MoS 2 -based films. • USER reaction quickly expanded the structure of graphene oxide-based films. • The most electrochemically active film was with the ratio 1:1 of ERGO to ex-MoS 2. • The displayed discharge capacity of ERGO/MoS 2 –1 (ratio 1:1) is 916 mAh/g. • Reduced graphene oxide-based films electrodes do not utilize non-active materials. In this paper, thin free standing films based on ultrafast self-expanded reduced graphene oxide (ERGO) and exfoliated molybdenum disulfide (ex-MoS 2) were prepared via vacuum-assisted filtration and tested as anodes in Li-ion half-cells. Three films with GO to ex-MoS 2 ratio of 1:1, 1:2 and 2:1 were assembled (ERGO/MoS 2 –1, ERGO/MoS 2 –2, ERGO/MoS 2 –3, respectively). Reduction of GO-based films was conducted via ultrafast self-expanded reaction (USER) in Ar atmosphere. This process not only immediately reduced GO but also significantly expanded films structure. The sample with the highest specific capacity and the highest stability consisted of GO and ex-MoS 2 with ratio of 1:1. The anode composed of this film showed approximately 6 times higher discharge capacity (916 mAh/g at 50 mA/g) than reference film (RGO/MoS 2 –1) where graphene oxide was thermally reduced in a furnace (145 mAh/g at 50 mA/g). Such high performance is associated with the expanded structure of ERGO allowing better lithiation yield and served as a protection of ex-MoS 2 against overexpanding upon charging/discharging process. What is more, the proposed Li-ion half-cells are free of any non-active materials e.g. carbon black or poly(vinyl difluoride) which are commonly used in batteries increasing the cost of the whole energy storage device. [Display omitted] [ABSTRACT FROM AUTHOR]

Bioinspired transition-metal catalysts seek to mimic the specific active site of metalloenzymes, as the multicopper oxidase, that can efficiently reduce dioxygen to water via a complete 4-electrons mechanism at low overpotential. However, the multicopper oxidase enzymes lack stability under operando conditions, hampering their application in fuel cell electrodes. Bioinspired multicopper catalysts present a remarkable electrocatalytic activity for the oxygen reduction reaction (ORR), where the structure and electronic properties of the ligands play a fundamental role. In this work, we explore the instantaneous catalytic activity and its evolution under operando conditions of two multicopper catalysts with different ligand flexibility, pyridyl ligand (CuL1), and pyridylmethyl ligand (CuL2), by conventional electrochemical techniques and scanning electrochemical microscopy (SECM). Both catalysts present similar instantaneous electrocatalytic activity with no significant role of the ligand, but there is a change in the mechanism. While the rigidity of CuL1 reduces the dioxygen via direct 4e-, the catalyst with higher flexibility (CuL2) follows a 2e− x 2e− mechanism. The production of H 2 O 2 as ORR byproduct evaluated by rotating ring-disk electrode (RRDE) and stability test evaluated under ORR operating conditions by SECM imaging of both catalysts demonstrated a higher decrease in catalytic activity and higher H 2 O 2 production in CuL2 than in CuL1, which evidences a ligand structure-reactivity correlation. These results contribute to the rational design of next generation of copper catalysts and open the door to a new methodology to evaluate the activity evolution under operando conditions by SECM. [Display omitted] [ABSTRACT FROM AUTHOR]

Lithium-sulfur (Li-S) batteries are considered to be competitive next-generation energy storage systems. However, practical applications are limited due to the shuttle of lithium polysulfides (LiPSs) and the poor electronic conductivity of the sulfur cathode, especially at high-rate currents. Here, we applied commercialized Acetylene black (AB) as separator coating in Li-S batteries. The stacking of AB nanospheres forms a void space that can physically adsorb polysulfides, store electrolytes, and promote lithium-ion diffusion; Simultaneously, it forms an excellent electronic conduction network that significantly improves the utilization of higher-order LiPSs. The thickness and composition of the coating can regulate the nucleation of crystalline S and Li 2 S to promote the uniform deposition of solid-phase particles. AB-150 releases an initial capacity of 961.3 mAh g−1 and still maintains at 825 mAh g−1 after 100 cycles with a capacity retention rate of 85.8% at 0.2C. Even remains at 371.2 mAh g−1 after 1000 cycles at 1C with a weak capacity decay rate of 0.06% per cycle. These understandings can also be extended to the design of polar/catalytic interlayer materials driving the large-scale application of Li-S batteries. [ABSTRACT FROM AUTHOR]

The application of gas diffusion electrodes (GDE) modified with carbon black materials at high overpotentials leads to the substantial production of H 2 O 2 via oxygen reduction reaction. The greatest challenge in this process lies in the reduction of the high overpotentials without affecting H 2 O 2 selectivity. One way of circumventing this problem is through the modification of GDEs with coordination compounds. The present work investigates the modification of Printex L6 carbon (CPL6) with different amounts of porphyrin complexes containing the following metallic centers: Mn, Co, Ni, Cu and Zn. The application of 5.0 wt % Co-Porphyrin/CPL6 modifier yielded the best results, with high selectivity for H 2 O 2 generation (90.2%) and marked improvement in catalytic activity (72.6%) compared to CPL6; these positive effects are attributed to the enhancement of both the interaction energy between Co and HOO* reaction intermediate and the effect of the conjugated π-electrons of the CPL6. The application of the modified GDE led to the electrogeneration of 340 mg L−1 of H 2 O 2 with energy consumption of 86.6 kWh kg−1 and 92.1% improvement in efficiency compared to the unmodified GDE. Thus, the findings show that the 5.0 wt % Co-Porphyrin/CPL6 modifier is an excellent cathode for application in H 2 O 2 generation and in electrochemical advanced oxidation processes. [Display omitted] [ABSTRACT FROM AUTHOR]

• High charge propagation of carbon electrode for electrochemical capacitor. • Adenine-derived carbon of high conductivity, good wettability and rich in nitrogen. • Comparison of gravimetric and volumetric metrics for carbon materials. Electrochemical capacitors are attractive power sources, especially when they are able to operate at high frequency (high current regime). In order to meet this requirement their constituents should be made of high conductivity materials with a suitable porosity. In this study, enhanced power and simultaneously high capacitance (120 F g −1 at 1 Hz or 10 A g −1) electrode material obtained from carbonized adenine precursor is presented. A micro/mesoporous character of the carbon with optimal pore size ratio and high surface area was proven by the physicochemical characterization. The beneficial pore structure and morphology resembling highly conductive carbon black, together with a significant nitrogen content (5.5%) allow for high frequency response of aqueous capacitor to be obtained. The carbon/carbon symmetric capacitor (in 1 mol L −1 Li 2 SO 4) has been tested to the voltage of 1.5 V. The cyclic voltammetry indicates a good electrochemical response even at high scan rate (50 mV s −1). The cyclability of the capacitor is comparable to the one operating with commercial carbon (YP50F). The adenine-based capacitor is especially favourable for stationary applications requiring high power. [ABSTRACT FROM AUTHOR]

• PFSA ionomer/N-doped CB is solely used as electrolyte in the PEFC cathode. • Carbon atoms adjacent to nitrogen derive a homogeneous distribution of the ionomer. • Cell performance is notably improved by superior activity and O 2 transportation. • This is attributed to suppression of catalyst poisoning and agglomeration of ionomer. • Cell durability is also enhanced due to higher graphitization of N-doped CB. An implementation of the polymer electrolyte fuel cell (PEFC) electrode, composed of the perfluorinated sulfonic acid (PFSA) ionomer with unprecedented uniform distribution, has recently gained a great attention due to its positive impact on the cell performance as well as durability. However, an issue with the conventional electrodes is a stronger adsorption of sulfonate terminal groups specifically onto Pt catalyst than carbon black (CB) support, that accelerates an inhomogeneous distribution of the PFSA ionomer. In this work, we report a novel PEFC electrode by introducing the ionomer immobilized onto nitrogen-doped carbon black (I/NCB) as electrode binder as well as electrolyte. The carbon atoms adjacent to nitrogen allow a considerable attraction with sulfonated groups over the NCB surfaces, which creates more homogeneous distribution of ionomer when compared with Pt/CB in the conventional electrode. As compared with the conventional electrode, the electrode employing I/NCB presents a superior activity towards oxygen reduction reaction (Pt mass activity increased from 91.3 to 139.6 A g−1) and mass-transport characteristics (mass-transport resistance decreased from 65.9 to 45.5 mΩ cm2), with the cell current density enhanced by 23% at 0.6 V. The enhanced cell durability is confirmed by less degradation in the electrochemically available surface area after the accelerated stress test of carbon support, mainly attributed to the promoted stability of NCB over CB. Given the advances in both performance and durability, the proposed electrode architecture based on I/NCB may provide an alternative pathway in obtaining better electrode kinetics and O 2 transport, along with an exceptional resistivity towards the carbon support degradation. [Display omitted] [ABSTRACT FROM AUTHOR]

• An effective strategy for enhancing microbial electrocatalysis of metal bioanode was developed. • Thermal oxidation of carbon black lead to an increase of oxygen content. • A 20% current density increase is achieved by thermal oxidation of carbon black at 500 °C in air. • The type but not the amount of the oxygen-containing groups facilitated electron transfer. • The quinone oxygen-containing groups were crucial for the enhanced microbial electrocatalysis. Metal-based materials, like stainless steel (SS), have been proved to be a promising bioelectrodes and current collectors for microbial fuel cells (MFCs). The microbial electrocatalysis performance of these metal electrodes could be greatly enhanced by surface modification, e.g. reactive bonding nanocarbon. Herein, we report the enhancement of microbial electrocatalysis of metal-based bioanode by thermal oxidation of the nanocarbon conductive filler, carbon black (CB). Oxidation of CB by thermal treatment at 400 and 500 °C in air (denoted as CB-400, CB-500) only led to slightly increase of oxygen content, from 4.34% in pristine CB to 5.54% in CB-500, while by thermal treatment at 110 °C in nitric (denoted as CB-N) led to a great increase of oxygen content to 9.58%. Microbial electrocatalysis results revealed that though the CB-N had the highest oxygen content, the bioanode it modified did not bring improvement of microbial electrocatalytic performance; while the bioanode modified by CB-500 led to an approximately 20% current density increase comparing to that modified by pristine CB. The quinone oxygen-containing functional groups of the CB-500 filler resulted by thermal treatment were found to be crucial for the enhancement of microbial electrocatalysis of the bioanode, because they could act as mediators to enhance the mediated electron transfer. This study provided an effective strategy for enhancing the microbial electrocatalysis of CB/SS composite bioanode by the appropriate oxidation of CB. [ABSTRACT FROM AUTHOR]

Thermoplastic carbon composite electrodes have been introduced by our group as novel electrodes with improved electrochemical properties and previously applied for accurate detection of biomarkers using voltammetric methods. Because of their exceptional properties, we hypothesized they would work well as potentiometric ion-selective electrodes as well. In this work, potassium selective thermoplastic electrodes (TPEs) were developed for potentiometric detection for the first time and applied in biofluids. TPEs were fabricated using mixture of polystyrene and polycaprolactone and two types of graphite (MG1599 and Nano19) for comparison, and modified with carbon black via drop-casting. Carbon black modification was optimized in the presence of various numbers of carbon black layers, while ion selective membrane components were optimized at different component ratios. Under optimized conditions, TPEs exhibited Nernstian response to K + with sensitivity of 59.3 ± 1.01 mV decade−1 and near-Nernstian response with sensitivity of 56.8 ± 1.7 mV decade−1 within a linear range of 1.0 × 10−4 M-1.0 × 10−1 M with a LOD of 1.0 × 10−4- M for Nano19- and MG1599-based TPEs, respectively. The K +-selective TPEs demonstrated rapid response (4 s) and excellent stability, repeatability and reproducibility. The applicability of electrodes were shown in human pooled urine and artificial interstitial fluid samples with potassium ion concentrations ranging from healthy and unhealthy levels. Therefore, the electrodes could be used in healthcare applications for accurate detection of K + exists in complex matrix and can be easily adapted to simultaneously monitor other ions for diagnosis of diseases due to miniaturization of TPEs. [Display omitted] [ABSTRACT FROM AUTHOR]

Ultrahigh power is needed beyond the state-of-the-art supercapacitors for emerging technologies. Towards this goal, nanostructured carbon materials have been extensively studied but unfortunately encountered with the difficulty in practical applications, which is largely due to their limited packing densities. In this work, we utilize a highly dense commercial activated carbon to develop high-rate nanocomposite electrodes and ultrahigh-power supercapacitors by compositing activated carbon with carbon nanomaterials, including zero-dimensional carbon black, one-dimensional carbon nanotube, and two-dimensional graphene. Enabled by the mixed packing (forming a unique point-to-line-to-plane contact morphology), diverse electrical conduction (forming a well-interconnected three-dimensional electrical conduction network), and varied porosity (forming a well-defined hierarchical porous structure) from these multiple constituents, the optimized quaternary nanocomposite electrode possesses a good combination of facilitated electron transport and enhanced ion diffusion and thus a twofold higher rate capability (capacitance retention: 83.3% vs. 28.9% at 80 A g−1 vs. 0.5 A g−1), twofold higher power density (84.1 kW kg−1 vs. 41.9 kW kg−1), and superior high-rate cycling stability (capacitance retention: 80.2% vs. 65.9% after charge/discharge at 10 A g−1 for 30,000 cycles) than its conventional activated carbon counterpart, while its high volumetric power density (50.5 kW L−1) strengthens its practical usefulness. Our research represents a novel approach to fabricate commercially available materials into practically useful ultrahigh-power supercapacitors at low cost, which may also be employed as a universal strategy to develop high-performance nanocomposites to benefit a wider range of application technologies. [ABSTRACT FROM AUTHOR]

• Nanosized VC was synthesized by disproportionation of V(IV) ions in molten salt. • The VC powder have excellent dispersibility and uniform size distribution. • The VC exhibits desirable electrochemical performances as an anode in LIBs and SIBs. • It is a new insight into the synthesis of high-performance carbide as anode in metal-ion batteries. Nanosized VC with an average particle size of ∼40 nm was synthesized by disproportionation of V(IV) ions on acetylene black template in molten (Na,K)Cl at 950 °C holding for 5 h. The as-synthesized VC has exhibited desirable electrochemical performances as an anode in lithium-ion batteries (LIBs), delivered a reversible discharge capacity of 597.8 mAh g−1 at 0.1 A g−1 and ∼397.8 mAh g−1 at 0.5 A g−1 in 200 consecutive cycles. It is noteworthy that nanosized VC also displayed impressive charge-discharge capacities in sodium-ion batteries (SIBs), released ∼252.5 mAh g−1 at 0.1 A g−1. This work provides a new insight into the preparation of high-performance carbide ceramics as anodes in metal-ion batteries. [Display omitted] Well-distributed nanosized VC was synthesized by a convenient and efficient synthesis method, utilizing disproportionation reaction of V(IV) in molten salt, exhibits excellent electrochemical performances in lithium ion batteries. [ABSTRACT FROM AUTHOR]

• A dual-coated multifunctional separator is prepared by a facile coating method. • The dense PMMA-LLZO layer provides strong physical and chemical confinements of polysulfides. • The porous AB layer enhances the redox conversion kinetics of polysulfides. • The assembled Li-S cell demonstrates excellent electrochemical performances. The lithium-sulfur (Li-S) battery has received widespread attention because of the high theoretical energy density and inexpensive raw material. However, some issues still restrict its commercialization, including the shuttle effect, the lithium dendrite growth and low safety, etc. In this work, a PMMA-LLZO/PP/AB multifunctional separator was designed and facilely prepared to overcome these problems. A composite dense layer of the PMMA and LLZO sheets with excellent interface stability was coated on one side of the PP separator to face lithium metal anode, which can inhibit the lithium dendrites growth and increase the safety. Meanwhile, this composite coating possesses high affinity with the liquid electrolyte and the soluble polysulfides, which can improve the ionic conductivity, effectively adsorb the polysulfides. An acetylene black (AB) layer was further coated on the other side of the PP separator to not only act as an electron conductor but also adsorb and hinder the migration of lithium polysulfides. The co-modified PMMA-LLZO/PP/AB separator displays remarkable electrochemical performances and an excellent thermal stability. The cell with the co-modified separator exhibits high specific capacities of 1456 mAh g−1 at 0.1 C and 969 mAh g−1 at 1.0 C, and retains a capacity of 413 mAh g−1 after 500 cycles, corresponding to a retention of 42.6% as well as a low decay of 0.114%/cycle. Especially, the cell with the multifunctional separator also displays a high capacity and a low decay even for a high sulfur mass loading cathode of 2.5–3.0 mg cm−2 or at a high temperature of 60 °C. The co-modified multifunctional separator has great application potential in the high-performance Li-S battery. [Display omitted] [ABSTRACT FROM AUTHOR]

The synergic combination of printed electronics and printed electrochemical sensors has recently emerged as a new route for developing smart chemical wearable devices applied to sweat monitoring. Sodium ion is one of electrolytes monitored in sweat to evaluate sweating level for electrolyte replacement recommendations. Herein, we report the development of new designed screen-printed electrodes, in which working electrode has been easily modified by drop-casting with the nanomaterial carbon black and a selective membrane cocktail, and the reference electrode with a polyvinyl butyral-based membrane. Once optimised all conditions, the screen-printed electrochemical sensor demonstrated no aqueous layer formation between working electrode and selective membrane, long-term potential stability, good shelf life, and resistance to interferences from oxygen and light. The carbon black-based sensor allowed for the detection of sodium ions in range 10-4 M e 1 M with a slope of 58 ± 3 mV/decade and a detection limit of 63 µM. The applicability for sweat analysis was evaluated by analysing three sweat samples collecting during running activity, obtaining concentrations of 44 ± 4 mM, 55 ± 6 mM, and 47 ± 3 mM, values in agreements with sodium ions content in healthy people, as well as using artificial sweat with recovery values of 90 ± 3%, 94 ± 2%, and 94 ± 5%. [ABSTRACT FROM AUTHOR]

The potential use of electrochemically polymerized polycarbazole as an additive in lithium-sulfur battery cathodes has been investigated. Optimization of the polymer properties considered solvent, electrolyte and current-time profile during electropolymerization. It was found that electrodeposition from LiClO 4 -acetonitrile electrolyte and constant-potential deposition (at 1.15 V vs Ag/Ag+) gives the highest initial discharge capacity. This is most likely due to an optimum combination of specific surface area and conductivity. To improve the quality of the cathode, a slurry of carbon disulfide and dimethyl formamide was devised to balance the dispersion of carbon black and the solubility of sulfur. In 2032-coin cells, against a lithium anode, a polycarbazole-sulfur (PCBz-S) cathode with 30% sulphur showed the highest initial discharge capacity. A very good coulombic efficiency of around 98% and a capacity retention of over 91% for 50 charge/discharge cycles were obtained for the optimized PCBz-S cathode. Based on the cycling performance, PCBz is a potentially useful additive to mitigate the polysulfide shuttle effect. In addition, the electropolymerized carbazole matches the performance of a commercial polypyrrole that has been widely used as a conductive binder. [ABSTRACT FROM AUTHOR]