High Electron Transfer Research Articles

High efficiency removal of methyl blue using phytic acid modified graphene oxide and adsorption mechanism

Phytic acid modified graphene oxide (PGO) has encouraging prospect in environmental application. Herein, PGO was fabricated with a simple hydrothermal method and used as adsorbent to remove methyl blue (MB). Elaborate inspection based on the hard-soft acid-base (HSAB) principle, spectroscopic characterization, as well as batch adsorption and fitting were conducted to unravel the adsorption mechanism. Results show, PGO efficiently adsorbs 89.08 mg·g−1 of MB in 22 min. HSAB principle proposes, high electron transfer (ΔN) and energy lowering (ΔE) induce covalent bond (chemical interaction), while low ΔN and ΔE induce electrostatic effect (physical interaction). Accordingly, both the first and second strongest interaction occurs between PA moiety and MB: π electrons of MB flows towards O atom in OH and O(–O–) of PA, respectively. Yet the third strongest interaction happens between GO moiety and MB: electron of O atom in OH group of GO flows towards N atom of MB. Above top three interactions are characterized by prominent ΔN and ΔE implying the formation of covalent bond. However, other interactions yield low ΔN and ΔE, suggesting the presence of electrostatic effect. HSAB principle conclusion was substantiated by FTIR and UV–Vis analyses. These findings confirm that PA modification enhances the adsorption affinity of graphene oxide. Thereby, chemical adsorption induced by physical interaction is proposed. This work may inspire the design of efficient adsorbent based on PGO framework for environmental restoration.

Catalytic pyrolysis of plastic waste to gasoline, jet fuel and diesel with nano MOF derived-loaded Y zeolite: Evaluation of temperature, zeolite crystallization and catalyst loading effects

Catalytic pyrolysis of municipal plastic waste can serve as a means of refining nature from the non-degradable plastic pollutants while producing a significant amount of liquid fuel required for the transportation industry. The low quality of the produced liquid fuel is often a fundamental challenge in pyrolysis, which can be overcome by utilizing catalysts. In this study, an upgraded zeolite Y catalyst has been employed. However, one of the main issues with zeolites is their small pore size, which restricts the entry of heavy polymer compounds and only allows small molecules to enter. To address this limitation, an innovative approach has been applied in this research where MIL-53 (Cu) is loaded onto the surface of the zeolite. After pyrolysis, it was determined that a composite of copper and its oxides, enclosed in a carbon nanocarbon shell C60 and C70, has been loaded onto the surface of the zeolite. This inexpensive composite exhibit behavior similar to noble and expensive metals due to its high electron transfer density. Additionally, analyses XRD, FTIR, BET, XRF, EDX, GC–MS, NH3-TPD and CHNSO were utilized for the characterization of the catalyst and the liquid fuel. Furthermore, three key parameters were selected for experimental design: temperature (375–525 °C), catalyst loading in the reactor (2.5–17.5 %), and support crystallinity percentage (0–100 %). Using a response surface approach, the impact of these parameters on the liquid fuel production efficiency was investigated. Ultimately, the produced liquid fuel was separated into three fractions: gasoline, jet fuel, and diesel. The effects of these primary parameters on the efficiency of each fuel type were determined using the response surface methodology.

Improved supercapacitors and water splitting performances of Anderson-type manganese(III)-polyoxomolybdate through assembly with Zn-MOF in a host–guest structure

Enhancing performance through the combination of polyoxometalates (POMs) clusters with metal–organic frameworks (MOFs) that contain various transition metals is a challenging task. In this study, we synthesized a polyoxometalate-based metal–organic framework (POMOF) named HRBNU-5 using a solvothermal method. HRBNU-5 is composed of Zn[N(C4H9)4][MnMo6O18{(OCH2)3CNH2}2]@Zn3(C9H3O6)2·6C3H7NO, which includes two components: Zn[N(C4H9)4][MnMo6O18{(OCH2)3CNH2}2]·3C3H7NO ({Zn[MnMo6]}) and Zn3(C9H3O6)2·3C3H7NO (Zn-BTC). Structural characterization confirmed the host–guest structure, with Zn-BTC encapsulating {Zn[MnMo6]}. In a three-electrode system, HRBNU-5 exhibited a specific capacitance of 851.3 F g−1 at a current density of 1 A/g and retained high stability (97.2 %) after 5000 cycles. Additionally, HRBNU-5 performed well in aqueous-symmetric/asymmetric supercapacitors (SSC/ASC) in terms of energy density and power density in a double-electrode system. Moreover, it demonstrated excellent catalytic performance in a 1.0 M KOH solution, with low overpotentials and Tafel slopes for hydrogen and oxygen evolution reactions: 177.1 mV (η10 HER), 126.9 mV dec–1 and 370.3 mV (η50 OER), 36.3 mV dec–1, respectively, surpassing its precursors and most reported studies. HRBNU-5′s positive performance is attributed to its host–guest structure, high electron-transfer conductivity, and porous structure that enhances efficient mass transport. This work inspires the design of Anderson-type POMOF electrode materials with multiple active sites and a well-defined structure.

Reviving Zn0 Dendrites to Electroactive Zn2+ by Mesoporous MXene with Active Edge Sites.

Zinc metal-based aqueous batteries (ZABs) offer a sustainable, affordable, and safe energy storage alternative to lithium, yet inevitable dendrite formation impedes their wide use, especially under long-term and high-rate cycles. How the battery can survive after dendrite formation remains an open question. Here, we pivot from conventional Zn dendrite growth suppression strategies, introducing proactive dendrite-digesting chemistry via a mesoporous Ti3C2 MXene (MesoTi3C2)-wrapped polypropylene separator. Spectroscopic characterizations and electrochemical evaluation demonstrate that MesoTi3C2, acting as an oxidant, can revive the formed dead Zn0 dendrites into electroactive Zn2+ ions through a spontaneous redox process. Density functional theory reveals that the abundant edge-Ti-O sites in our MesoTi3C2 facilitate high oxidizability and electron transfer from Zn0 dendrites compared to their in-plane counterparts. The resultant asymmetrical cell demonstrates remarkable ultralong cycle life of 2200 h at a practical current of 5 mA cm-2 with a low overpotential (<50 mV). The study reveals the unexpected edge effect of mesoporous MXenes and uncovers a new proactive dendrite-digesting chemistry to survive ZABs, albeit with inevitable dendrite formation.

Direct determination of paraquat herbicide by square-wave voltammetry by two-step transfer mechanism at heterogeneous boron-doped carbon nanowall electrodes

Boron-doped carbon nanowalls (B:CNW) versus boron-doped diamond (BDD) materials were investigated for the effective electrochemical detection of highly toxic herbicide paraquat (PQ). Depending on the surface morphology and functional groups of BDD and B:CNWs, the electrochemical absorption and detection of the target analyte PQ revealed different detection mechanisms. The surface absorption mechanism was mainly observed for BDD, while for B:CNWs, both surficial and edge absorption were observed due to the sharp edges of carbon nanowalls. This effectually drives the high heterogenous electron transfer kinetics at absorption sites. Detection of PQ was carried out in phosphate buffer solution with an optimized pH of 10 and parameters of the square-wave voltammetry. Comparative studies show higher voltammetric current peak heights for B:CNWs (∼90.5 μA) than BDD (∼7.5 μA) at a much lower PQ concentration of 4 μM. B:CNWs show a higher sensitivity of 11 μA/μM/cm2 than BDD of 2.23 μA/μM/cm2, hence BDD shows a LOD of 1.8 μM, whereas B:CNWs have a much lower LOD of 0.47 μM. Density functional theory calculations (DFT) show a higher propensity of the B:CNW models toward electrocatalytic reduction of the PQ. Moreover, the proposed two-step detection mechanism is strongly supported by the distribution of the PQ electrostatic potential in different oxidation states in conjunction with the slab surfaces. The higher the sensitivity, the lower the LOD, and the excellent performance of B:CNWs in the detection of PQ in real water samples also suggests its potential for use in the environmental monitoring and assessment of emerging pollutants.

In-situ engineering of 3D porous Co nanoparticles incorporated in B/N Co-doped carbon nanotube/nanofiber networks as integrated cathode materials for Zn-air batteries

Rational design and construction of low-cost and highly efficient bifunctional catalysts toward oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is crucial for the commercialization of the rechargeable Zn-air batteries (ZABs). Herein, a 3D self-standing bifunctional catalytic electrode has been successfully achieved by in-situ confinement of Co nanoparticles into B/N co-doped carbon nanotube/nanofiber well-integrated networks (Co-B/N-CNTs@CFs). The purpose of designing such a 3D network structure is to optimize the electronic structure of the active sites for high electrocatalytic activity, ensure continuous and fast electron and charge transfer for high utilization of active sites, and avoid the abscission and aggregation of nanocatalysts for high electrocatalytic stability, which is confirmed by a series of experimental, characterization, and theoretical studies. As a result, the Co-B/N-CNTs@CFs as integrated cathode materials deliver efficient and stable OER/ORR performance with a ΔE of 0.59 V, largely outperforming the benchmark Pt/C-RuO2 electrode (0.71 V), and hence leading to appealing applications in both the assembled aqueous and flexible solid-state ZABs. This study forges a new path for the production of integrated cathode while enhancing their superiority, allowing for the construction of energy storage devices.

A 3D cross-linked hierarchical hydrogel E-skin with sensing of touch position and pressure

Artificial hydrogel electronic skin (E-skin) sensing systems have received considerable attention due to their ability in providing tactile perception. Recent advancements in hydrogel E-skin have allowed for simultaneous sensing of touch position and pressure through construction of sensor arrays. However, the fabrication process is complex, and the sensing resolution is limited by the size and number of array cells. Here, we report a multi-modal sensory E-skin based on a polyvinyl alcohol (PVA) hydrogel embedded with carbon nano-materials, which can recognize touch position and pressure simultaneously without constructing arrays. Combining the advantages of high electron transfer efficiency of 1D nanotube and 2D graphene nanosheet, the 3D hierarchical cross-linked polydopamine (PDA) modified reduced graphene oxide (rGO)/carboxylic multiwalled carbon nanotube (MWCNT-COOH) composites were proposed as a conductive filler, which was added by nano-doping to hydrogel substrate to gain an elastic modulus and stretchability of the hydrogel similar to that of human skin. Meanwhile, a surface-capacitive touch (SCT) system and piezoresistive technology were adopted to sense touch position and pressure due to the stability of conductive networks and the piezoresistive properties of carbon nanomaterials. Our E-skin device demonstrates superior sensing performance and provides a new direction for designing novel E-skin sensor devices.

Graphene‐Based Nano Materials: Biomedical Applications

AbstractGraphene is a single layered two‐dimensional structure of graphite and it has been a flaming topic of research due to its remarkable properties. The efficiency of graphene‐based materials is exploited in many spheres of life ranging from biosensing, targeted drug delivery, bio‐imaging, quantum physics, transportation, energy storage devices, faster electronics, and many more. Graphene is made of a monolayer of sp2 carbon atoms organized in a hexagonal pattern with a C−C bond length of 1.42 A. Graphene has attracted interest in the development of electrochemical sensors and biosensors due to its excellent electrical conductivity, significant surface area, and high electron transfer potential. Because of these exclusive characteristics, it has also become a suitable contender for extensive biomedical uses that favors the differentiation of human mesenchymal stem cells (MSC) into bone cells and inhibit proliferation of cells, fluorescence quenching, drug/gene delivery, tissue engineering and antitumor treatments. In last ten years, notable research has been conducted to explore its biomedical applications. Encouraged by its numerous successful integrations into the biomedical fields, the up‐to‐date developments of graphene applications in various dimensions of biomedical field such as biosensors, gene and drug delivery, photo‐thermal therapy, bio‐imaging and tissue engineering are summarized here.

Elucidating the impact of sulfur precursors on the reactivity, toxicity, and colloidal stability of post-sulfidized nanoscale zerovalent iron

The sulfur precursor-induced sulfidation effectively enhances the nanoscale zerovalent iron (nZVI) reactivity. However, due to the batch-to-batch variation in synthesis and reaction conditions, the sulfur precursor that confers superior reactivity to sulfidized nZVI (S-nZVI) and its application potential are undetermined. This study evaluated the impact of six sulfur precursors (Na2S, Na2S2O4, S0, Na2S2O3, K2S6, and sulfate reduction effluent [a sulfide-containing effluent]) on the reactivity, toxicity, and colloidal stability of S-nZVI. The reactivity enhancement induced by sulfidation of the different sulfur precursors was inconsistent and dependent on the contaminant. In the removal of trichloroethylene (TCE) and hexavalent chromium Cr(VI) in aqueous solution, S-nZVI, with a high Fe0 content, hydrophobicity, and electron transfer properties (i.e., S-nZVINa2S and S-nZVINa2S2O3), yielded relatively high capacities. In the removal of tetracycline (TC) by S-nZVI, the performance was relatively unaffected by the sulfur precursors. The toxicity evaluation demonstrated that S-nZVIs showed a limited toxicity (less than 0.35-log) to Escherichia coli (E. coli) in simulated groundwater. Despite sulfidation marginally improving the colloidal stability of nZVI—by reducing the interparticle forces—, the S-nZVI particle settling was observed, within 60 min, at the bottom of the vial containing the suspension. Overall, none of the sulfur precursors was manifestly preferable to the others. Na2S, Na2S2O3, and SR-effluent were recommended for use in low sulfur content post-sulfidation processes considering the material performances and costs. These findings contribute to the understanding of the effect of the sulfur precursors on the reactivity and application potential of S-nZVI, thereby providing guidance for tuning S-nZVI properties and selecting suitable sulfur precursors for specific in situ remediation scenarios.

Electrocatalytic dechlorination of Florfenicol using crystalline Co3S4/Ni3S4 nanowires arrayed on nickel foam via cathodic reduction

Chlorinated antibiotics, particularly Florfenicol (FF), pose a serious global threat to humans and animals by contaminating freshwater and causing water pollution. Electrocatalytic dechlorination (ECH) is effective for removing chlorinated organic compounds during wastewater treatment and water remediation, however, there are limited reports on high-performance, cost-effective, and environmentally friendly cathode materials. In this study, a catalyst was prepared using a two-step hydrothermal process, and a vertically grown 2D Co3S4/Ni3S4 heterostructure was constructed on a nickel foam electrode. Owing to its inherently high electron transfer performance and H* adsorption properties, extensive dechlorination of FF could be achieved via cathodic reduction. The electrode formed using a 100 mM Na2S concentration during the hydrothermal reaction exhibited an optimal crystal composition and morphology, resulting in a substantial electrocatalytic dechlorination effect exhibiting nearly 100 % FF removal after 120 min at −1 V vs Ag/AgCl. The experimental results indicated that the dechlorination of FF is primarily achieved via direct electron transfer, with the degradation rate decreasing by only 5 % after the addition of 400 mM tert-butanol, confirming that H* played a supporting role. Therefore, this study proposes a cost-effective and sustainable electrochemical approach for reducing chlorinated antibiotics using a highly efficient non-noble metal electrode material. It can be successfully utilized as an effective, eco-friendly electrochemical strategy for the removal of similar antibiotics.

Facile one-pot synthesis of plasmonic gold nanoparticles decorated porphyrin-metal organic framework for photocatalytic hydrogen evolution

Plasmonic metals and single-atom nanocomposites have recently gained attention for their enhancement of photocatalyst ability to harvest energy from visible light photons and consequently increase their photoactivity. Over the last decade, the functionalization of Au nanoparticles has been extensively studied to support photocatalytic processes such as hydrogen generation. Furthermore, porphyrin metal-organic frameworks (MOF) materials have demonstrated promising properties such as high crystallinity, surface area, and electron transfer to favor this reaction. Thus, herein Au@PCN(M) nanocomposite was designed by anchoring surface-modified Au nanoparticles into a porphyrin MOF (PCN(M)) where M represents single-atom transition metals (Pt and Co), these nanocomposites were synthesized by both one-pot and post-synthesis methods. Post-synthesis method displayed a higher yield in comparison to the one-pot method, which could be related to the higher crystallinity and metalation of Co and Pt species on PCN-222. Nevertheless, the obtained results for the one-pot method demonstrated that the developed approach is comparable in terms of performance and is promising for the synthesis of efficient plasmonic photocatalysts and their possibility of scale-up in the future.

Rapid PFOS mineralization with peroxydisulfate activation process mediated by N modified Fe-based catalyst

As the cheap and efficient catalysts, the iron-based catalysts have been considered as one of the most promising catalysts for peroxydisulfate (PDS) activation and the development of high-performance iron-based catalysts are attracting growing attentions. In this work, a magnetic Fe-based catalysts (Fe/NC-1000) was obtained by using Fe modified ZIF-8 as the precursor and used to activate the PDS for the degradation of perfluorooctane sulphonate (PFOS). Morphology and structure analysis showed that the resulted Fe/NC-1000 catalyst was displayed porous spheres (40–60 nm) and mainly composed of Fe0, FeNx and carbon. When Fe/NC-1000 was employed to activate the PDS (0.1 g/L of catalyst dosage, 0.5 g/L of PDS dosage and at initial pH of 4.6), the Fe/NC-1000/PDS system exhibited excellent efficiency (97.9 ± 0.1) % for PFOS (10 mg/L) degradation within 30 min. The quenching tests and EPR results revealed that the Fe/NC-1000/PDS system degraded PFOS primarily through singlet oxygen (1O2) evolution and electron-transfer process. Besides, based on the degradation byproducts determined by LC-MS-MS, the PFOS first occurred de-sulfonation to form PFOA, and then the resulted PFOA underwent stepwise defluorination in the Fe/NC-1000/PDS system. Density Functional Theory (DFT) calculations and electrochemistry tests strongly confirmed that Fe/NC-1000 exhibited high electron transfer efficiency, resulting in promoted performance on activating PDS. Importantly, the results of Ecological Structure-Activity Relationship (ECOSAR) analysis showed that the intermediates were lowly toxic during the PFOS degradation, manifesting a green process for PFOS removal. This study would provide more understandings for the persulfate activation process mediated by Fe-based catalysts for Perfluorinated alkyl substances (PFAS) elimination.

Modulating the redox couples of graphene-like NBC-TiO2@FeMn through forming photo-Fenton system for boosting persulfate activation to accelerate the contaminant degradation

The sluggish cycling of redox couples hampers the practical application of catalysts in contaminant degradation. Herein, a novel strategy was introduced by constructing a photo-Fenton system onto the graphene-like NBC to realize the ultrafast modulating of redox couples during the contaminant degradation. The constructed NBC-TiO2@FeMn (NBTF) exhibits a higher proportion of reductive redox couples (Fe (II)/Mn (II)) after the degradation, which is attributable to the photo-Fenton system and the graphene-like NBC with high electron transfer efficiency. Density functional theory (DFT) calculations also confirm that constructing the photo-Fenton system on graphene-like NBC greatly enhances electron transfer, enabling the modulation of redox couples during the degradation process. During activation, various reactive oxygen species (including •OH, SO4•-, high-valent metal oxides, and non-radical pathways) are generated, effectively degrading pulp wastewater Tetrachloroguaiacol (TeCG) with a degradation efficiency of 98.8 % within 14 min. Quenching experiments and EPR spectroscopic analysis indicate that the degradation of TeCG is mainly mediated by hydroxyl radicals (•OH) and sulfate radicals (SO4•-) as predominant pathways, while high-valent metal oxides, 1O2 and direct electron transfer mechanisms act in a cooperative manner. Substitution reaction on active sites reveal that both FeMn LDH and graphene-like NBC are identified as the main active sites, with Mn exhibiting superior PMS activation compared to Fe. A possible degradation pathway of TeCG is proposed, and a decrease in the toxicity of intermediates is observed. This study provides a new perspective on the modulation of redox couples in SR-AOPs to realize sustainable pollutants degradation.

The Linkage-Moderated Covalent Organic Frameworks with C=N and NN on Charge Transfer Kinetics Towards the Robust Photocatalytic Hydrogen Activity.

Since the linkages structured in covalent organic frameworks (COFs) usually impact the charge transfer behavior during photocatalytic hydrogen evolution reaction (pc-HER), linkage dependence on charge transfer kinetics should be further claimed. Herein, COFs with N-based linkages and pyrene-based building nodes are constructed to enable us to obtain new clues about the charge transfer behavior and evolution tendency relevant to linkages at a molecular level for pc-HER. It is demonstrated that photo-excited electrons preferably move to the N sites in C=N linkage for pc-HER and are trapped around NN linkage as well. A high electron transfer rate does not point to high photocatalytic activity directly, while a small difference between the electron transfer rate and electron recombination rate ΔkCT - CR predicts the inefficiency of charge transfer in Azod-COFs. Contrarily, large value of ΔkCT - CR in the case of Benzd-COFs, demonstrats an unimpeded charge transfer process to result in boosted pc-HER rate (2027.3 µmol h-1 g-1 ). This work offers a prominent strategy for the reasonable design of efficient photocatalysts at the molecular level for structural regulation and achieves an efficient charge transfer process for the pc-HER process.

AQDS-mediated dissimilatory reduction of iron (hydr)oxides induces the formation of large grain vivianite: A new insight for phosphorus pollution control in sediment

Quinones plays a crucial role in iron (hydr)oxides dissimilatory reduction and the geochemical cycle of elements. However, the interfacial reactions and the subsequent effect of phosphorus (P) in sediments remain unclear. To clarify it, 9,10-anthraquinone-2,6-disulfonic acid (AQDS) was used to participate in reduction of hematite and goethite by Geobacter metallireducens GS-15, and the interfacial electron transfer between iron (hydr)oxides and AQDS were also explained. Results showed that AQDS had a higher promotion effect on the reduction of goethite than hematite, and more than 41% of goethite was reduced compared to the control check, with an 80.6 mg g−1 phosphorus immobilized. Vivianite was produced in this system, and the size of vivianite in hematite-AQDS and goethite-AQDS groups increased 7.59% and 57.78%, respectively, compared to the corresponding groups without AQDS. The highest weight of vivianite-P was in the Goe-AQDS group by X-ray absorption near edge structure (XANES). Electrochemical characteristics showed that the interfacial electron transfer rates of hematite and goethite with AQDS adding were 7.49 s−1 and 9.03 s−1, respectively. Therefore, high electron transfer efficiency led more microbial iron reductions, which generated high concentrations of Fe(Ⅱ) and facilitated the increasing of production and grain size of vivianite. These findings provide a new understanding of vivianite generation and phosphorus immobilization.

Conjugated polymerized bimetallic phthalocyanine based electrocatalyst with Fe−N4/Co−N4 dual-sites synergistic effect for zinc-air battery

The bifunctional oxygen catalyst is essential for zinc-air batteries (ZABs). Here, an efficient bifunctional oxygen catalyst, PPcFeCo/3D-G, is obtained through π-π interaction between the conjugated polymerized iron-cobalt phthalocyanine (PPcFeCo) with excellent thermal stability and three-dimensional graphene (3D-G). The bimetallic synergistic effect of PPcFeCo, verified by DFT (Density functional theory) calculation, and π-π interactions enhances the catalytic activity and durability of the PPcFeCo/3D-G. Regarding electrochemical performance, the PPcFeCo/3D-G with a high electron transfer number (3.98, @0.768 V vs. RHE) has excellent half-wave potential (E1/2 = 0.890 V vs. RHE) and exhibits outstanding reversibility (ΔE = 0.700 V, ΔE = Ej=10 − E1/2). The liquid ZAB (LZAB) employed PPcFeCo/3D-G displays a high power density (222 mW cm−2), a specific capacity (792 mA h g−1), and excellent durability (120 h). This work has guiding significance for the preparation of high-efficiency bifunctional catalysts.

Structural characterization and electrochemical performance of laser-induced graphene: Insights into electron transfer kinetics and 4-aminophenol sensing

Laser-induced graphene (LIG) is increasingly gaining importance as a 3D porous graphene material with outstanding properties. Here, LIG structures are realized for electrochemical sensors by patterning polyimide Kapton using a visible 405 nm laser under ambient conditions. The LIG electrodes for flexible electrochemical sensors show a large surface area with a hierarchical porosity distribution along the cross-section.To optimize the laser parameters, we investigated the electron transfer (ET) kinetics and the electrochemical performance of LIG surfaces produced with an exposure time varied from 10 ms to 50 ms. Characterization of the resulting LIG was performed to understand the correlation between the resulting electrochemical properties and the LIG surface properties by optical microscopy and Raman spectroscopy. The electrochemical properties were evaluated in ferri-ferrocyanide [Fe(CN)6]3−/4− by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The highest electron transfer rate constant was registered at an exposure time of 10 ms. However, for an exposure time of 20 ms, the electrochemical behavior is better due to both high surface area and high electron transfer rate constant.A voltammetric 4-Aminophenol sensor is developed as a proof-of-concept device. It exhibits a good analytical performance realizing a low limit of detection at a level of 9.23 nM in the concentration range from 10 nM to 400 nM. The results demonstrate the suitability of LIG for the development of efficient, disposable, and flexible electrochemical sensors. The developed technological approach supports sustainability while simplifying production and reducing costs.

Molten salt strategy to activate biochar for enhancing biohydrogen production

Generally, dark fermentation (DF) of hydrogen (H2) synthesis has low H2 production from industrial-scale plants. In this study, campus greening wastes-ginkgo leaves were used to produce molten salt-modified biochar (MSBC) and nitrogen (N2)-atmosphere BC (NBC) in molten salt and N2 environment at 800 °C, respectively. MSBC showed excellent properties including high specific surface area and electron transfer ability. After supplementation with MSBC, H2 yield rose by 32.4% compared to the control group without carbon material. Electrochemical analysis revealed MSBC improved the electrochemical properties of sludge. Furthermore, MSBC optimized the microbial community structure and increased the relative abundance of dominant microbes, thus promoting H2 production. This work provides a deep understanding of two carbons that play vital roles in increasing microbial biomass, supplementing trace element and favoring electron transfer in DF reactions. Salt recovery achieved 93.57% in molten salt carbonization, which has sustainability compared with N2-atmosphere pyrolysis.

Multilayered nano Ti3C2Tx electrode: An ultrasensitive electrochemical sensor for rutin antioxidant detection

Multilayer two-dimensional (2D) structures (MXenes) provide promising advantages in biomedical applications. Using SEM and XRD characterization techniques, the synthesized substance was identified. Our results show that Ti3C2Tx-GCE possesses a significant number of active sites, enhancing its electrocatalytic activity and electrochemical sensing abilities for RT oxidation. The multilayered Ti3C2Tx-GCE that was produced had good electrochemical properties and acceptable pore structures. Additionally, it exhibited remarkable linearity starting from 1 to 10 μM and demonstrated high sensitivity for the electrochemical measurement of RT, with an impressively low limit of detection (LOD) of 0.345 μM. EIS studies revealed that the synthesized multilayered Ti3C2Tx possessed a significantly low charge transfer resistance and a high electron transfer rate constant. Our research lays the groundwork for designing a multilayered Ti3C2Tx network, which opens up intriguing possibilities for creating high-performance electrochemical sensors for use in biomedicine and clinical settings.

A Suitable Porous Micro/Nanostructured Cu and Cu–Ni Film: Evaluation of Electrodeposition Behavior, Electrocatalytic Activity, and Surface Characterization of Porous Film

Selecting an appropriate catalyst with a high surface area and proper electron transfer ability can accelerate improved hierarchical catalysts. In this research, an appropriate porous film was formed by the dynamic hydrogen bubble template (DHBT) method with a pulse current (PC) electrodeposition. CH3COOH was added to the Cu electrodeposition bath as a non-ionic surfactant, CTAB was added as a cationic surfactant, and Ni was added as an alloying element. Results show the formation of a nano-dendritic porous Cu film. The presence of surfactants, especially CTAB, causes dendritic arms to be more elegant and denser, with more round voids. Furthermore, adding Ni sulfate to the bath containing both surfactants resulted in a porous Cu film with the most improved HER behavior by decreasing the overpotential (η 10) from 389 to 195 mV RHE−1 and the Tafel slope from 174 to 93 mV dec−1 in a 1.0 M KOH solution. According to the results of the electrochemical active surface area (ECSA), normalized LSV curves, and charge transfer resistances, the co-deposition of Cu and Ni revealed more active surface area and improved intrinsic HER catalytic activity. Therefore, these properties can convince researchers to utilize an improved porous Cu–Ni electrode for energy applications.