Rich Sites Research Articles

High sensitivity and ultra-low detection limit of violet phosphorus-based formaldehyde gas sensor by ultrasonic-assisted laser ablation

Formaldehyde (HCHO) pollution has emerged as a progressively critical environmental concern, with the detection of formaldehyde at trace levels being an indispensable requirement. Violet phosphorus (VP) nanoplates, recognized as innovative two-dimensional materials, are promising candidates for gas sensing due to their rich active sites and substantial specific surface area. This work pioneered the use of ultrasonic-assisted laser ablation in the synthesis of VP nanoplates. The as-produced VP nanoplates had the lateral dimension of 6.5 μm and the thickness of 2–6 nm (1–5 layers), which was strongly influenced by the ablation techniques employed and the processing parameters. The VP nanoplates demonstrated excellent sensitivity towards formaldehyde: gauge factor is 7.23 × 109; and resistance response is 144.6 % for detecting 20 ppb of formaldehyde. The detection limit is only 3 ppb. This work employed experiments and calculations to study the sensing mechanism. The binding energy between VP/G and HCHO is −1.276 eV, demonstrating the strong chemical adsorption. This paper provided a novel approach to fabricate VP nanoplates with superior formaldehyde sensitivity and ultra-low detection limitation, thereby showcasing significant potential for applications in detecting of air pollution.

A DFT study of eugenol adsorption onto pure and Si-doped Al12N12 and B12N12 fullerene-like nanocages

Density functional theory (DFT) methods have been employed in this work to study the adsorption behavior of eugenol (Eug) on the external surface of pure and Si-doped Al12N12 and B12N12 fullerene-like nanocages. All calculations were performed using the M062X-D3 functional combined with the 6-311 + G(d,p) basic sets. In order to probe the reliability of the DFT method, three other functionals (B3LYP-D3, CB3LYP-D3 and WB97XD) were employed and no significant difference was observed in the adsorption energy values of the most stable configurations (AEII and BEII). Also, the complexes are found to be stable in standard conditions in gas and aqueous phases, and the adsorption process is found to be exothermic and spontaneous. Interestingly, Si-doped nanomaterials (Si-AEII and Si-BEII) form the most stable adsorbent-adsorate molecular states (Eads = −90.07 and −61.42 kcal/mol respectively) in gas phase. Furthermore, Si-AEII and Si-BEII complexes exhibit the highest reactivity, characterized by the lowest values of the HOMO-LUMO energy gap (5.50 and 7.07 eV respectively). MEP map of the studied systems showed electron rich and electron deficient sites. Natural bond orbital analyses revealed that the interaction of Al12N12 with Eug is mainly due to the strong electron delocalization LP(2)O10 → LP*(2)Al47 (E(2) = 34 kcal/mol), whereas in Eug-B12N12 complex, it is mainly due to the electron delocalization LP(2)O10 → P*(4)B36 (E(2) = 96.53 kcal/mol). The QTAIM analysis revealed that Si–O and Al–C/B–C bonds linking eugenol to doped cages are attractive weak interactions and their nature have been confirmed via RDG/NCI analyses. Indeed, the present study revealed the suitability of Si-doped Al12N12 and B12N12 fullerene-like nanocages for the efficient drug delivery of eugenol.

Photoluminescence Tuning of Stable CaYGaO4: Bi/Eu via Compositional Modulation and Crystallographic Site Engineering for nUV wLEDs.

The olivine-based gallate CaYGaO4 (CYG) with unique cationic ordering, rich lattice sites, and self-photoluminescence (PL) is suitable for application as a host of phosphor. However, research in this area is still in its early stages, especially in high-quality full-spectrum white lighting. Herein, novel CYG: Bi3+/Eu3+ with a controllable PL property is designed based on energy transfer and superposition of emissions from blue self-PL, blue PL of Bi3+, and red-PL of Eu3+. Intriguingly, PL intensity and quantum efficiency could be enhanced via codoping Li+/Zn2+ separately/simultaneously because of their two intentional functions as both charge balancer and flux. Unlike self- and Eu3+ PL, Bi3+ PL is quite sensitive to the lattice environment owing to its exposed 6s2 electronic configuration and is tuned via codoping Sr2+ to regulate the nephelauxetic effect and crystal field splitting concurrently around Bi3+. Meanwhile, for further regulating the PL of Bi3+ and obtaining "warm" white light, La3+ is codoped into the phosphor via crystallographic site engineering to control the substitution trends of Bi3+ at distinct lattice sites. Finally, as a proof-of-concept, a full-spectrum phosphor-converted white-light-emitting diode device under nUV pumping with remarkable color rendering index (Ra), high luminous efficiency, and chemical/thermal stability is achieved by utilizing the individual CYG:Bi/Eu/Li/Zn/Sr/La phosphor via a remote "capping" packaging method.

N-Doped Carbon Modified (NixFe1-x)Se Supported on Vertical Graphene toward Efficient and Stable OER Performance.

NiFe-based nanomaterials are extensively studied as one of the promising candidates for the oxygen evolution reaction (OER). However, their practical application is still largely impeded by the unsatisfied activity and poor durability caused by the severe leaching of active species. Herein, a rapid and facile combustion method is developed to synthesize the vertical graphene (VG) supported N-doped carbon modified (NixFe1-x)Se composites (NC@(NixFe1-x)Se/VG). The interconnected heterostructure of obtained materials plays a vital role in boosting the catalytic performance, offering rich active sites and convenient pathways for rapid electron and ion transport. The incorporation of Se into NiFe facilitates the formation of active species via in situ surface reconstruction. According to density functional theory (DFT) calculations, the in situ formation of a Ni0.75Fe0.25Se/Ni0.75Fe0.25OOH layer significantly enhances the catalytic activity of NC@(NixFe1-x)Se/VG. Furthermore, the surface-adsorbed selenoxide species contribute to the stabilization of the catalytic active phase and increase the overall stability. The obtained NC@(NixFe1-x)Se/VG exhibits a low overpotential of 220mV at 20mAcm-2 and long-term stability over 300h. This work offers a novel perspective on the design and fabrication of OER electrocatalysts with high activity and stability.

Outstanding CO2 Photoreduction in Single-Atom Thulium Modified Carbon Nitride.

CO2 reduction photocatalysts are favorable for obtaining renewable energy. Enriched active sites and effective photogenerated-carriers separation are keys for improving CO2 photo-reduction. A thulium (Tm) single atom tailoring strategy introducing carbon vacancies in porous tubular graphitic carbon nitride (g-C3N4) surpassing the ever-reported g-C3N4 based photocatalysts, with 199.47µmolg-1h-1 CO yield, 96.8% CO selectivity, 0.84% apparent quantum efficiency and excellent photocatalytic stability, is implemented in this work. Results revealed that in-plane Tm sites and interlayer-bridged Tm-N charge transfer channels significantly enhanced the aggregation/transfer of photogenerated electrons thus promoting CO2 adsorption/activation and contributing to *COOH intermediates formation. Meanwhile, Tm atoms and carbon vacancies both benefit for rich active sites and enhanced photogenerated-charge separation, thus optimizing reaction pathway and leading to excellent CO2 photo-reduction. This work not only provides guidelines for CO2 photo-reduction catalysts design but also offers mechanistic insights into single-atom based photocatalysts for solar fuel production.

Hollow-Structured Co-MoSx/Graphene Trifunctional Electrocatalyst for Self-Powered Hydrogen Production System.

Developing a single electrocatalyst that can facilitate both rechargeable aqueous metal-air batteries and water splitting has become a crucial focus in renewable-energy technologies. This necessitates addressing the three distinct electrocatalytic reactions: the electrochemical oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER). Despite significant efforts, the creation of a alkaline medium based trifunctional catalyst with high activity at a low cost has proven to be a considerable challenge. Currently, Pt and its alloys have been considered as the most active catalysts for the ORR and HER, whereas noble-metal oxides such as IrO2 and RuO2 are considered as the golden standards of OER catalyst. However, noble-metals based catalyst have been suffered from their high cost, limited reserves in the Earth’s crust, and poor electrocatalytic stability. Moreover, these noble metals face challenges in simultaneously exhibiting trifunctional catalytic activity for ORR, OER, and HER. In recent study, Transiton metal sulfides(TMSs) have great attraction as trifunctional catalyts due to their eqrth abudance, tunnable band structure, and crystal structure. especially, one of widely used TMCs is MoS2 because of their Pt-like high catalytic activity for HER as well as thermodynamic electrochemical stability and rich catalytic sites in the planar nature. However, the most stable 2H (hexagonal) phase MoS2 suffers from poor electrical conductivity, low wettability, and aggregation indced reducing active catalytic sites and resulting high resistance. 2H MoS2 also shows poor activity for OER and ORR, thereby hampering its practical applications as trifunctional catalyst. To overcome this threshold, various strategies have been conducted to improve their electrochemical charateristics, such as defect engineering, heterojunction foramtion, phase transform and integrating porosity control. However, commonly considered method to synthesis requires complex multi-steps with high temperature, vaccum system, explosive gas, and toxic etchant.In this study, we successfully synthesized the homogeneous growth of a Co-based nanometer-scale metal-organic framework (MOF) on graphene oxide at room temperature. Furthermore, a facile one-pot solvothermal method was employed to synthesize Co-MoSx/Graphene, which consists of a hollow, heterogeneous bimetallic sulfide (Co3S4/MoS2 with Co-S-Mo bonding) within a sandwiched graphene/MoS2 layer, demonstrating superior trifunctional activity and stability. Incorporating a conductive graphene layer between MoS2 layers is an effective strategy for not only realizing high electrical conduction to MoS2 layers, but also increasing MoS2 interlayer spacing for high ion accessibility. Besides, a variety of techniques, including Cs-corrected scanning transmission electron microscope (Cs-STEM), X-ray diffraction(XRD), and X-ray absorption spectroscopy (XAS), are used to confirm the atomic configurations of Co-MoSx/Graphene structure and morphologies. Also, Raman, Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) were conducted to investigating the binding structure and chemical states. Furthermore, The internal electric field (IEF) within heterojunction, which induced from the differing electron density of the bimetallic species and the sandwiched graphene are contribute not only electron density structure optimization for enhancing reaction kinetics but also accelerating electron-hole exchange. The IEF in the microporous-heterostructure accelerates the diffusion of reaction intermediate with sufficient mass transport and facilitates a Graphene/MoS2-to-Co-MoSx pathway for enhancing redox kinetics of sluggish OER and ORR. Consequently, the OER and ORR-inactive MoS2, HER, and ORR-inactive Co3S4, along with less catalytically effective graphene, demonstrate outstanding performance when combined in the bimetallic sulfide based highly active heterojunctional structure. To investigate the electrochemical catalytic properties of Co-MoSx/Graphene, Rotating disk electrode(RDE) was used with three electrode measurment. The presence of MoS2/Graphene on Co3S4 and Co-MoSx bonding species in Co-MoSx/Graphene enhances the alkaline electrochemical catalytic activity by reducing overpotential and Tafel slopes(220 mV, 110 mV dec-1 in HER and 320 mV, 55.8 mV dec-1 in OER) under 1M KOH solution. Moreover, the ORR performance was evaluated by using Koutecky-Levich (K-L) Plot with different rotating speeds under 0.1M KOH. The electron transfer number (n) is closed theoretical value of 4.0 also shows outstanding performance of the onset potential, half-wave potential and kinetic current density (0.88 V, 0.67 V, and 10.4 mA cm-2), which is comparable that of Pt/C (0.92 V, 0.8 V, and 10.3 mA cm-2). Furthermore, Co-MoSx/G based rechargeable Zinc-Air battery achieve over 85% of theoretical zinc utilization efficiency and 1.4 times higher power density than a Pt/C + RuO2 air cathode based system. We believe that this work could provide a rational strategy for achieve trifunctional electrocatalyst and high performance self-powered hydrogen production system.This research was supported by the National Research Foundation of Korea (2022M3H4A1A04096482, RS-2023-00229679) funded by the Ministry of Science and ICT.

Engineering Water-Lotus-like Iridium-Cobalt Carbonate Hydroxides on Plasma-Treated Carbon Fibers for Enhanced Electrocatalytic Oxygen Evolution.

The sluggish kinetics of the oxygen evolution reaction (OER) in alkaline water electrolysis remains a significant challenge for developing high-efficiency electrocatalytic systems. In this study, we present a three-dimensional, micrometer-sized iridium oxide (IrO2)-decorated cobalt carbonate hydroxide (IrO2-P-CoCH) electrocatalyst, which is engineered in situ on a carbon cloth (CC) substrate pretreated with atmospheric-pressure dielectric barrier discharge (DBD) plasma (PCC). The electrocatalyst features petal-like structures composed of nanosized rods, providing abundant reactive areas and sites, including the oxygen vacancy caused by the air-DBD plasma. As a result, the IrO2-P-CoCH/PCC electrocatalyst demonstrates an outstanding OER performance, with overpotentials of only 190 and 300 mV required to achieve current densities of 10 mA cm-2 (j10) and 300 mA cm-2 (j300), respectively, along with a low Tafel slope of 48.1 mV dec-1 in 1.0 M KOH. Remarkably, benefiting from rich active sites exposed on the IrO2-P-CoCH (Ir) heterostructure, the synergistic effect between IrO2 and CoCH enhances the charge delivery rates, and the IrO2-P-CoCH/PCC exhibits a superior electrocatalytic activity at a high current density (300 mV/j300) compared to the commercial benchmarked RuO2/PCC (470 mV/j300). Furthermore, the IrO2-P-CoCH/PCC electrocatalyst shows exceptional OER stability, with a mere 1.3% decrease with a current density of j10 for 100 h testing, surpassing most OER catalysts based on CC substrates. This work introduces a novel approach for designing high-performance OER electrocatalysts on flexible electrode substrates.

Carbon cloth supporting (CrMnFeCoCu)3O4 high entropy oxide as electrocatalyst for efficient oxygen evolution reactions

High-entropy oxides (HEOs) have received more attentions for the oxygen evolution reaction (OER) due to their rich active sites and high configurational entropy. However, the difficulty of electron transfer during the catalysis process limits the application of HEOs in OER catalysis. Herein, we proposed the carbon cloth (CC) supporting (CrMnFeCoCu)3O4 HEO with spinel structure synthesized by the hydrothermal method following with the calcination. The carbon cloth used as the support of HEO could improve the conductivity and stability of the catalyst. Meanwhile, the excellent catalytic activity of HEO with the synergistic effects of multiple metal elements would be maintained. And the homo-disperse HEO nanoparticles were exposed on the surface carbon fibers, which was conducive to contact with electrolyte. Based on the above merits, the intrinsic catalytic activity of (CrMnFeCoCu)3O4/CC was enhanced, which was attributed to the self-regulating electronic structure and the fine HEO nanoparticles exposed on the surface of catalysts. And the catalytic kinetic process of (CrMnFeCoCu)3O4/CC was accelerated, mainly due to its conductivity and richer oxygen vacancies. The (CrMnFeCoCu)3O4/CC exhibited the outstanding OER performance with an ultralow overpotential (210.8 mV @10 mA·cm−2), a smaller Tafel slope value (59.4 mV·dec−1), and super long-term durability, which was competitive with other transition metal oxides based catalysts and noble metal oxides. Therefore, the excellent OER performance implied that the (CrMnFeCoCu)3O4/CC is an OER catalyst candidate for practical application.

Floatable Termination-Vacant MXene Architecture for High-Performance and Cost-Effective Photothermal Dehydrogenation.

Liquid hydrogen carriers have garnered considerable interest in long-distance and large-scale hydrogen storage owing to their exceptional hydrogen storage density, safety, and compatibility. Nonetheless, their practical application is hampered by the low hydrogen production rate and high cost, stemming from poor thermal utilization and heavy reliance on noble metals in solar bulk dehydrogenation platforms. To conquer these challenges, we devise an economical all-in-one architecture comprising the photothermal catalytic termination-vacant MXene and a highly insulated melamine substrate. This design floats on the air-reactant interface to efficiently drive solar interfacial dehydrogenation. The melamine enables interfacial heat localization to improve the thermal utilization, providing a high reaction temperature. Meanwhile, the MXene with termination vacancies exposes rich active sites for formic acid dehydrogenation, and simultaneously high performance and cost-effectiveness can be realized. This work offers fresh perspectives on the design and application of photothermal catalytic MXene, broadening the prospects for hydrogen storage using liquid hydrogen carriers.

Fabrication of cobalt phosphide/nitride/carbon nanotube composite: An efficient bifunctional catalyst for hydrogen and oxygen evolution

Designing composites with rational structure and composition is a promising approach to obtain efficient electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). In this study, zeolitic imidazolate frameworks-67 (ZIF-67) is employed as a self-sacrificing template to synthesize Co/carbon nanotubes (CNTs) precursor, which is subsequently in-situ nitrided and phosphorized to form cobalt phosphide/nitride/carbon nanotubes (Co2P/Co4N/CNTs) composite. The realized Co2P/Co4N composite exhibits heterogeneous nanoparticle microstucture with an average diameter of approximately 10 nm, encapsulated by carbon nanotubes with a porous dodecahedral array. Moreover, there is a well-defined interface between cobalt phosphide, cobalt nitride phases, and carbon nanotubes species. Benefiting from the synergistic effect of Co4N and Co2P, rich active sites, and high conductivity of CNTs, the composite catalyst demonstrates remarkable HER and OER activities, requiring overpotentials of 228 and 389 mV to support 100 mA cm−2 current density, respectively. This work presents a novel strategy for designing efficient bifunctional catalysts towards HER and OER.

High-vacuum-calcined multi-MOF mixed-matrix membrane for CH4/N2 separation

Methane/nitrogen (CH4/N2) separation remains a persistent challenge owing to the similar polarities, kinetic diameters, and boiling points of CH4 and N2. Herein, a novel method is proposed for enhancing the separation performance of CH4/N2 via vacuum resistance calcination, which uses surface-carbonized and hardened ZIF-8 (SCH-Z), MOF-74-Ni (SCH-M), and UiO-66-NH2 (SCH–U). The nanoparticles treated by vacuum resistance calcination remain the microporous characteristics of MOF, while introducing additional mesoporous structure and unsaturated metal sites. Such multistage pore structure and rich metal sites display a significant improvement in the CH4 adsorption over N2. In addition, the separation performance of multiple metal–organic frameworks (MOFs) mixed matrix membranes (MMMs) fabricated by homogeneously mixing the alkaline polymer polyvinylamine (PVAm) with SCH-M/SCH-Z and SCH-M/SCH–U was investigated, respectively. When the measured pressure was 0.1 MPa and the binary filler loading was 48 %, the PVAm/(SCH-M)0.7(SCH-Z)0.3/MPSf MMM exhibited outstanding CH4/N2 separation performance (CH4 permeance of 2888.48 GPU and selectivity of 4.38). Furthermore, when the loading of the binary filler was 45 %, the ideal CH4/N2 selectivity and CH4 permeance of PVAm/(SCH-M)0.67(SCH–U)0.33/MPSf MMM are 5.57 and 2263.94 GPU, respectively. This study provides a novel idea that introducing multi-MOF nanoparticles into MMMs for optimizing gas separation performance.

Advances in the selection of functional monomers for molecularly imprinted polymers: A review.

Molecularly imprinted polymers, a type of special polymer materials, are widely used in biosensing and other fields due to their ability to specifically recognize target molecules, often called "artificial receptors.". Nowadays, researchers are constantly exploring new design and synthesis methods for molecularly imprinted materials to improve the selectivity and sensitivity of molecularly imprinted materials. Among them, the selection of functional monomers has attracted great attention. This review comprehensively analyzes and discusses the selection methods of functional monomers. The most commonly used functional monomers among different types of templates are screened based on the structural properties of the template molecules, including the selection of functional monomers among ion-imprinted polymers, protein-imprinted polymers, and bacterial imprinted polymers. The rich binding sites and functional group types of multifunctional monomers are also highlighted to advance the development of molecular imprinting technology. The article further explores the current challenges and prospects in the selection of functional monomers and emphasizes multiplex experiments and computer simulations as important directions for future research. This review provides comprehensive information and constructive guidelines for researchers in selecting functional monomers in areas such as analytical chemistry and biosensors.

Engineering rich defects in nitrogen-doped porous carbon to boost oxygen reduction reaction kinetics

Metal-free carbon-based materials offer a promising alternative to Pt-based catalysts for the oxygen reduction reaction (ORR). However, challenges persist due to its sluggish kinetics and poor acid ORR performance. Here, we introduce a novel nitrogen-doped porous carbon with rich defects sites (such as pentagons, edge and vacancy defects) (PV/HPC) via a simple etching strategy. The PV/HPC demonstrates long-term stability and exceptional catalytic activity with half-wave potential of 0.9 V and average electron transfer number of 3.98 in alkaline solution while 0.78 V and 3.78 in acidic solution, indicating its efficiency and robustness as an ORR catalyst. Additionally, it achieves a higher kinetic current density of 91.9 mA cm−2 at 0.8 V, which is 1.75 times that of Pt/C (52.5 mA cm−2). Furthemore, it enables Al-air battery to attain a maximum power density of 487 mW cm−2, compared to 477 mW cm−2 for the Pt/C catalyst. Density functional theory (DFT) calculations elucidate that the introduction of multifunctional defects in nitrogen-doped porous carbon collectively reduces the reaction energy barrier of the departure of OH* and boosts the oxygen reduction reaction kinetics. This work presents a simple method to design durable and effective carbon-based ORR catalysts.

HISTORICAL AND CULTURAL HERITAGE OF BUNDELKHAND REGION CONSERVATION, VISUALIZATION, USING G.I.S TECHNOLOGIES

This research paper investigates the conservation, visualization, and study of Bundelkhand's historical and cultural heritage using Geographic Information Systems (GIS) technologies. Located in central India, Bundelkhand is renowned for its rich historical sites, including ancient temples, forts, and palaces. These sites face significant preservation challenges due to environmental degradation, neglect, and socio-economic constraints. This study explores the application of GIS technologies in documenting, analyzing, and visualizing Bundelkhand's heritage. GIS offers powerful tools for creating detailed inventories, assessing the physical condition of structures, monitoring changes, and enhancing public engagement through immersive visualizations. The paper highlights the transformative potential of GIS in heritage conservation through case studies of the Khajuraho temples and the Orchha Fort Complex, demonstrating how GIS facilitates comprehensive documentation, condition assessment, and informed conservation strategies. While GIS technologies present numerous benefits, such as enhanced data integration and improved spatial analysis, challenges related to data accuracy, technical expertise, and resource constraints must be addressed. The study underscores the need for a balanced approach that combines traditional conservation methods with advanced GIS technologies to ensure the sustainable preservation of Bundelkhand's cultural legacy. By leveraging GIS, conservationists, researchers, and policymakers can safeguard Bundelkhand's heritage, promote sustainable tourism, and foster a deeper appreciation for the region's rich cultural history. This research contributes to the broader discourse on digital transformation in heritage conservation, emphasizing the critical role of GIS in preserving and promoting cultural heritage in the digital age.

Phytocoenological and ecological typification of the March Mushroom (Hygrophorus marzuolus (Fr.) Bres.) habitat in Bijambare, Sarajevo Canton

Biodiversity of mushrooms in FBiH is poorly researched, as well as the areas of distribution and ecological conditions under which mushrooms develop. This is also the case with the March Mushroom, so the main goal of the paper is to present the ecological conditions under which it develops. For the research, we used the Braun-Blanket (1932) method with all necessary parameters related to the selected habitat. These are: phytocenological affiliation, flora element, indicator value, and life form. The abundance of fungi was provided according to Tortić and Lisiewska (1971). Chemical analysis of the soil with basic parameters was also done. March Mushroom was detected in the Abieti-Fagetum in the locality of Motike within the "ZP Bijambare". This is the new site for the March Mushroom. Primary indicator values prevail in the association. Species of the order Fagetalia are the most numerous within the researched association. Hemicryptophytes prevail among the life forms. A total of 25 floral elements from 9 groups were determined. The largest number of species belongs to the sub-Atlantic-sub-Mediterranean group. The floral element with the largest number of determined species is subatl-smed. Fortunately, this locality is quite far from hiking trails, which is important, considering it as an extremely rich site of the March Mushroom.

Soft carbon filled in expanded graphite layer pores for superior fast-charging lithium-ion batteries

The slow kinetics and lithium deposition of graphite anode are considered the key limitations of fast-charging lithium-ion batteries. Expanded graphite has shown tremendous potential for the improvement of rate performance due to its massive active sites released and lifted lithium storage platform. However, the risk of structural collapse caused by fast charging will reduce the cycling life of the expanded graphite anode. Herein, this study designed a stable structure of expanded graphite by filling its layer pores with pitch-derived soft carbon (EGC). The honeycomb-like EGC is a great fast-charging candidate material with rich active sites, enlarged ion transport channels, and efficient ion transport interfaces. As the experimental and simulation results, the EGC electrode demonstrated significantly fast lithium-ions storage kinetics and durable long cycle life, compared to commercial fast-charging graphite anode. Notably, the EGC//LiNi0.8Co0.1Mn0.1O2 full cell delivered a superior fast-charging and stability performance (near 20 min charging for 80 % State of Charge). The simple multifunctional modification strategy for graphite anode in this work provides a new approach for superior fast-charging lithium-ion batteries.

Enhancing reaction interface with modified microporous layers for high-efficiency hydrogen production in PEM water electrolysis

Improving the reaction interface is imperative for increasing catalyst utilization and enhancing overall cell performance in proton exchange membrane electrolyzer cells (PEMECs). Herein, a thin Nafion-carbon-mixed microporous layer coated carbon paper (Nafion-C MPL/CP) is first developed as an efficient cathode liquid/gas diffusion layer for PEMECs. With the Nafion-C MPL/CP, low cell voltages of 1.64, 1.74 and 1.84 V are delivered, which are 50, 80 and 140 mV lower than those of the conventional bare carbon paper at 2, 4 and 6 A/cm2, respectively, achieving about 3-fold higher catalyst utilization. Meanwhile, superior performance is also demonstrated compared to the commercial PTFE-C MPL/CP. The remarkable performance of the Nafion-C MPL/CP should be attributed to the enhanced reaction interface, which not only provides rich active sites with abundant electron and proton transport pathways for the electrochemical reaction but also reduces the interfacial contact resistance and mass transport losses. Moreover, excellent stability of the Nafion-C MPL/CP is demonstrated at a current density of 1.8 A/cm2 with no performance degradation during over 100-h operation. Due to the enhanced reaction interface with significantly improved catalyst utilization, the developed Nafion-C MPL/CP shows great potential to reduce the hydrogen production cost and accelerate PEMEC commercialization.

Conformal sulfidation of HKUST-1 for constructing porous Cu2S/CuO octahedrons realizing highly sensitive non-enzymatic glucose detection

Metal–organic frameworks (MOFs) are believed to be promising precursors for constructing novel and efficient catalysts for glucose sensing. Herein, HKUST-1 precursors are first fabricated using a one-pot hydrothermal approach, and then HKUST-1 is converted into porous Cu2S/CuO octahedrons through conformal sulfidation with the help of OH− ions. The as-obtained Cu2S/CuO composite can provide rich electrochemical active sites and promoted electric transfer kinetics. Benefiting from these combined merits, the as-fabricated Cu2S/CuO composite is confirmed to be a high-performance catalyst, with high sensitivities of 8269.45 and 4140.82 μA mM−1cm−2 in the corresponding ranges of 0.05 ∼ 0.6 mM and 0.6 ∼ 1.2 mM, respectively. Moreover, the as-prepared electrode materials possess good anti-interference ability, reproducibility and long-term stability. This work opens up new avenues for the design and preparation of transition metal sulfide composites.

In light of myth: photography as truth in Roland Barthes’s Camera Lucida

ABSTRACT Wishing to access the referential nature of things, the later Roland Barthes turned to premodern modes of thinking that emphasise presence, exteriority, and certainty. This essay shows this turn by elaborating on the Platonic, mythical, and tragic subtexts of his Camera Lucida. The photographic pose – interpreted variously through tragic masks, sacred icons, or documentary transparency – offers a rich site to reflect on the objectivity of experience. Though its memories are subjective, photography’s vivid effect shares in the universality promised by myth, which is also an imagistic mode of experience. The tension between the studium (techne/rhetoric) and the punctum (wound/experience) leads Barthes to affirm the incontrovertible reality of the latter over the artificiality of the former. Additionally, photography’s temporality of the past functions as a confirmation of presence rather than absence: the no-more does not signify what is not there, but corroborates in its melancholy what once was. In short, the light of photography in Camera Lucida is not so much a technical device required by an artistic medium but the very light of truth that grounds the referentiality of existence.

Political protest landscapes in Catalonia: language choice, utopian/dystopian discourse and “Catalans”-“Spaniards” identities

ABSTRACT Catalonia has become a rich site to investigate minorised-language identity, with the reemergence of a movement calling for independence. Our case study analyses how pro-/anti-secessionist protests are (counter)-fought in urban Linguistic Landscapes. We approach LLs as identity-markers and place-makers delivering messages of political subversion/dominance where majority/minorised-language choice and utopian/dystopian discourse become crucial for understanding their meanings during social upheaval, with renewed nationalist protests linked to an independence Referendum. We employed a content analysis based on a semiotic/semantic interpretation and thematic categorisation of the data. We show that two antithetical “Catalans”/“Spaniards” identities reemerge which mobilise either utopian projects written in Catalan or dystopian visions in Spanish, through intertextuality. The former, categorised as pro-independence “political resistance LLs,” project a hopeful impossible to extend a liberating possible. The latter, pro-unionist “threats to Catalan protesters LLs,” reinstate order, enforcing the suppression of dissent. This reveals that ethnolinguistic identities are newly reconfigured/resignified, unpacking how a social-semiotics focus on language choice and utopia/dystopia can prefigure social conflict development.