Oxidation Research Articles

Enhancing the oxygen reduction reaction in microbial fuel cell by using NiFe-LDH@NiCo2S4@MWCNT as cathode catalyst

Enhancing the oxygen reduction reaction in microbial fuel cell by using NiFe-LDH@NiCo2S4@MWCNT as cathode catalyst

Reactive metal–support interaction of In2O3/crystalline carbon hybrid support for highly durable and efficient oxygen reduction reaction electrocatalyst

Reactive metal–support interaction of In2O3/crystalline carbon hybrid support for highly durable and efficient oxygen reduction reaction electrocatalyst

Star-shaped ZIF-derived carbon-based electrocatalysts with FeNX active sites for enhanced oxygen reduction reaction in high-performance zinc-air batteries

Star-shaped ZIF-derived carbon-based electrocatalysts with FeNX active sites for enhanced oxygen reduction reaction in high-performance zinc-air batteries

Modulating oxygen reduction reaction activity in nitrogen-doped porous carbon via Al-N-C incorporation for enhanced performance in liquid and solid-state Zn-air batteries

Modulating oxygen reduction reaction activity in nitrogen-doped porous carbon via Al-N-C incorporation for enhanced performance in liquid and solid-state Zn-air batteries

Design of a Peroxidase‐Based Gas Diffusion Electrode for Bioelectroenzymatic Applications

We report here the design and application of an all‐in‐one gas diffusion electrode (GDE) combined with surface immobilized horseradish peroxidase (HRP) capable of in situ generation of hydrogen peroxide (H2O2) from air and simultaneous oxidation of a model substrate (ABTS) within a single‐cell electrochemical reactor. Carboxyl‐functionalized multiwalled carbon nanotubes (MWCNT‐COOH) were employed as an electrocatalyst for oxygen reduction reaction producing 719 ± 97 µM h−1 H2O2 at −0.2 V (vs Ag/AgCl) as an electron acceptor for HRP. We investigated two immobilization strategies to obtain HRP‐modified biocathodes using covalent amide conjugation between primary amine groups of HRP and carboxyl groups of MWCNT‐COOH (GDE/MWCNT‐COOH/HRP) and entrapment into a cross‐linked pyrene‐modified linear poly(ethylenimine) matrix (GDE/MWCNT‐COOH/Py‐LPEI/HRP). Fourier transform infrared spectroscopy (FT‐IR) and scanning electron microscopy (SEM) were used to characterize such surface modifications. The apparent catalytic activity achieved by HRP‐modified biocathodes via either covalent conjugation or entrapment into a polymer film was 311 ± 31 U mg−1 and 174 ± 17 U mg−1, respectively, as compared to the activity of freely diffusing 188 ± 23 U mg−1. The interfaces were reused showing 55% and 82% residual activity after 5 consecutive cycles for GDE/MWCNT‐COOH/HRP and GDE/MWCNT‐COOH/Py‐LPEI/HRP, respectively. Our findings illustrate prospects for integrating GDE and surface‐bound peroxidases for H2O2‐dependent electroenzymatic reactions, offering a promising platform for diverse applications in bioelectrosynthesis.

Electronic descriptors for designing high-entropy alloy electrocatalysts by leveraging local chemical environments

High-entropy alloys (HEAs) present a vast compositional space for fine-tuning electrocatalytic activities, leveraging millions of distinct active sites on the surface. However, the intricate local chemical environment poses challenges to the rational and efficient design of HEA electrocatalysts with high reactivity. Here, focusing on noble-metal HEAs for oxygen reduction reactions, we propose a straightforward yet effective descriptor for quantitively determining the local reactivities of HEAs. This descriptor is based on a linear combination of the intrinsic d-band filling of the active center and the neighborhood electronegativity. Our model offers an accurate and robust description of the binding strengths of intermediates with different adsorption configurations on HEAs, supported by external density functional theory calculations. Importantly, the local environmental electronegativity of the HEA surface is strongly related to the d-band profile of the center atom(s) embedded within. Finally, we establish a library of activity maps for HEAs encompassing nine noble-metal elements, suggesting that Pd-rich and Ir-rich alloys, such as Pd–Ag, Ir–Pt, Ir–Au compositions, hold promise as potential candidates for optimal electrocatalysts.

Valorization of Sargassum spp. biomass as a promising source of electrocatalysts for energy generation based on life cycle assessment

Valorization of Sargassum spp. biomass as a promising source of electrocatalysts for energy generation based on life cycle assessment

Bimetallic self-supported AuCu alloy aerogel with abundant diffusion channels for regulating oxygen reduction reaction by electronic structure modulation for zinc-air battery application

Bimetallic self-supported AuCu alloy aerogel with abundant diffusion channels for regulating oxygen reduction reaction by electronic structure modulation for zinc-air battery application

Anchoring ordered PtZn nanoparticles on MOF-derived carbon support for efficient oxygen reduction reaction in proton exchange membrane fuel cells

Anchoring ordered PtZn nanoparticles on MOF-derived carbon support for efficient oxygen reduction reaction in proton exchange membrane fuel cells

Tailoring local electronic structure to achieve reversible anion redox chemistry of layered oxide cathodes for high-performance sodium-ion batteries

Tailoring local electronic structure to achieve reversible anion redox chemistry of layered oxide cathodes for high-performance sodium-ion batteries

Modulation of redox chemistry of δ-MnO2 electrode by lithium inserting: experiments and first-principles calculations

Modulation of redox chemistry of δ-MnO2 electrode by lithium inserting: experiments and first-principles calculations

Doping dependency of chitosan and PAA controlled CdSe quantum dots for catalytic and bactericidal behavior by inhibiting DNA gyrase and DHFR through molecular docking.

The presence of toxic dyes in industrial waste dramatically diminishes the beneficial effects of remediation efforts. To overcome the hazardous impacts of dyes on biodiversity and environment, we integrated polymers into nanoparticles to substantially enhance their functionality and performance. 2 and 4wt% of chitosan (CS) and 3wt% of polyacrylic acid (PAA) doped cadmium selenide (CdSe) nanostructures (NSs) were prepared by co-precipitation approach. CdSe quantum dots (QDs) exhibit a narrow band gap energy, high solubility, and tunable properties, which are appropriate for redox reactions but show less adsorption and catalytic behavior. In this work, catalytic and antibacterial activities of CdSe QDs enhanced upon the integration of PAA due to increment in surface area confirmed by BET analysis. Furthermore, the addition of CS escalates the dye degradation and microbes evolve to the interaction of CdSe surface with the functional groups of CS. Highly doped CdSe shows significant inhibitory zones (8.65 to 9.30mm) against gram-positive bacteria Staphylococcus aureus (S. aureus). In addition, the inhibitory activity of CS/PAA-CdSe nanostructures against DNA gyrase and dihydrofolate reductase (DHFR) in S. aureus was elucidated using molecular docking investigations, providing a rationale for their bactericidal action.

Novel functional hydrogels based on lignin‑silver nanoparticles with adhesion, antimicrobial, antioxidant and anti-freezing properties for wound dressings and pressure strain sensors.

As wound dressings and wearable electronics advance, it is critical to develop an efficacious strategy for integrating a variety of powerful functions into hydrogels. In this work, sodium lignosulfonate‑silver nanoparticles and the functional [2-(methacryloyloxy) ethyl] dimethyl-(3-sulfopropyl) ammonium hydroxide structure (SBMA) are introduced into the multifunctional lignin-based hydrogel system. The sodium lignosulfonate‑silver nanoparticles, by catalyzing multiple redox reactions, facilitate the swift curing of hydrogels at room temperature. This process is advantageous for the structural refinement of hydrogel polymer segments and the integration of multiple functionalities. The synergistic effect of functional structure and nanoparticles bestows the hydrogel with superior adhesion, mechanical properties, antimicrobial properties and antioxidant properties. The introduction of a functional structure not only deferments the release of sodium lignosulfonate‑silver nanoparticles, but also imparts satisfactory conductivity and anti-freezing properties to the hydrogels. In applications related to wound dressings and pressure strain sensors, hydrogels demonstrate excellent potential. They effectively facilitate wound healing and enable the monitoring of limb movement. This work introduces a simple and effective approach to prepare lignin-based functional hydrogels, exhibiting significant potential for wound dressings and pressure strain sensors applications.

Applying hollow octahedron PtNPs/Pd-Cu2O nanozyme and highly conductive AuPtNPs/Ni-Co NCs to colorimetric -electrochemical dual-mode aptasensor for AFB1 detection.

Aflatoxin B1 (AFB1) is a secondary metabolite produced by Aspergillus flavus and Aspergillus parasiticus. This toxin is highly carcinogenic and toxic, posing a serious threat to human and animal health. AFB1 primarily enters the human body through contaminated food, particularly peanuts, corn, nuts, and wheat. These foods are easily contaminated with AFB1 during planting, harvesting, storage, and processing. Therefore, the establishment of an accurate and sensitive method for the detection of AFB1 is essential to safeguard food safety and human health. This study applied catalytic hairpin assembly (CHA), hybridization chain reaction (HCR), hollow octahedron PtNPs/Pd-Cu2O bifunctional nanozyme, and AuPtNPs/Ni-Co NCs to develop a colorimetric-electrochemical dual-mode aptasensor for AFB1 detection. Here, Pd-Cu2O corner-etched octahedra with cavities and oxygen vacancy defects were first designed, followed by the synthesis of PtNPs/Pd-Cu2O through the loading of PtNPs to enhance the peroxidase-like activity of Pd-Cu2O. PtNPs/Pd-Cu2O effectively catalyzed the generation of blue oxidation products from 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide (H2O2). It also enhances the redox reaction of methylene blue (MB) at the electrode and improves the electrochemical signal. AuPtNPs/Ni-Co NCs possess a large specific surface area and excellent conductivity, enhanced the redox signal of MB. Additionally, the aptasensor combined the enzyme-free amplification strategies of CHA and HCR to improve sensitivity. The aptasensor reached limit of detection (LOD) 0.76pg/mL in electrochemical mode and 0.49pg/mL in colorimetric mode. The designed colorimetric-electrochemical dual-mode aptasensor exhibits high selectivity, specificity, stability, and reliability. The dual-mode aptasensor had been successfully applied to the spiked analysis of edible oils, peanuts, and cornmeal, demonstrating excellent recovery rates. Therefore, the dual-mode aptasensor had a wide application prospect in the field of quality supervision and food safety.

Removal of Cr6+ in water by superoxide anion-mediated redox reaction assisted by lignin-rich kiwifruit twig biochar: Application of DFT calculation.

This research aims to investigate the role of reactive oxygen species (ROS) in the adsorption and reduction of Cr6+ on lignin-rich biochar under dark conditions and under various oxygen treatment conditions. The research found that under aerobic conditions, the reduction content of Cr6+ (0.38mg) and the production content of ·O2- (20.36×10-6mg·L-1) are the highest, followed by untreated conditions (0.32mg, 15.03×10-6mg·L-1), and the lowest under anaerobic conditions (0.21mg, 5.14×10-6mg·L-1). Compared with anaerobic conditions, the reduction content of Cr6+ increased by 1.52 times under untreated conditions. Meanwhile, under anaerobic conditions, ·O2- disappeared, indicating that ·O2- had played an important role in the reduction of Cr6+. Kinetic results showed that the role of ·O2- in the reduction of Cr6+ mainly occurred in liquid solution. DFT calculations confirmed that C-OH was the main electron supplier in the reduction process of Cr6+, and there was a positive correlation between the production content of ·O2- and the content of C-OH in liquid solution. The present research is expected to provide a scientific basis for the transformation of Cr6+ on lignin-rich biochar in liquid solution.

Back Cover

By harnessing the powers of both light and electricity, photoelectrocatalysis could enable challenging redox reactions under extremely mild conditions, and the cover image shows a three‐component net‐oxidative sulfonocyclization of DABSO leading to sulfono 4‐pyrrolin‐2‐ones with an oxidatively activated radical precursor. The in situ generated DABCO functions as an electron shuttle between the photocatalytic cycle and the reactants. More details are discussed in the article by Liang et al. on pages 491—500. image

DFT insights into the role of penta-SiC₂ in enhancing Li-S battery performance through polysulfide anchoring

DFT insights into the role of penta-SiC₂ in enhancing Li-S battery performance through polysulfide anchoring

Bimetallic active sites with tailored d-bands boost multistep sulfur redox reactions for enhanced lithium-sulfur battery performance

Bimetallic active sites with tailored d-bands boost multistep sulfur redox reactions for enhanced lithium-sulfur battery performance

The impact of the structural transformation mechanism of fulvic acid on redox capacity during composting with different biowastes.

Fulvic acid (FA) derived from composting functions can act as electron shuttle, facilitating and expediting the redox reaction during the composting process. However, limited research has been conducted on the redox capacity and structural transformation of FA during composting with different biowastes. The Fe (II) production quantity of the single S. oneidensis MR-1 (MR-1), MR-1 with FA derived from lignocellulose-rich and lignin-rich composting after 300h inoculation were up to 2.28, 3.67 and 2.52mmol/L, indicating the redox capacity of FA in lignocellulose-rich composts was stronger than that in lignin-rich composting. Furthermore, two-dimensional correlation spectroscopy revealed that FA derived from lignocellulose-rich composting exhibited a layer-by-layer structure, characterized by aromatic functional groups and other groups. In contrast, FA obtained from lignin-rich composting displayed an arrangement where the inner aromatic functional groups were obstructed by the methyl group. The structural equation model revealed that the high relative abundance and aromatic functional groups of FA derived from lignocellulose-rich composting process exert a direct influence on the reduction of Fe (III)-citrate, and the methyl groups of FA obtained from lignin-rich composting process also directly linked to the reduction of Fe (III)-citrate. The present study thus posited that the quantity of aromatic functional groups within outer of FA structure during composting constituted a crucial factor influencing its redox capacity. The findings offer novel insights into the transformation mechanism of FA derives from diverse biowastes and its redox characteristics, thereby providing significant guidance for the application of FA in mitigating environment pollutants.

Complex gene-dependent and-independent mechanisms control daily rhythms of hematopoietic cells.

The abundance and behaviour of all hematopoietic components display daily oscillations, supporting the involvement of circadian clock mechanisms. The daily variations of immune cell functions, such as trafficking between blood and tissues, differentiation, proliferation, and effector capabilities are regulated by complex intrinsic (cell-based) and extrinsic (neuro-hormonal, organism-based) mechanisms. While the role of the transcriptional/translational molecular machinery, driven by a set of well-conserved genes (Clock genes), in nucleated immune cells is increasingly recognized and understood, the presence of non-transcriptional mechanisms remains almost entirely unexplored. Studies on anucleate hematopoietic components, such as red blood cells and platelets, have shown that auto-sustained redox reaction cycles persist and operate in mammals. This opens to the possibility that transcriptional and non-transcriptional circadian mechanisms might coexist in nucleated immune cell populations, potentially complementing each other. It is becoming increasingly clear that disruption of the circadian rhythm at the central level (core clock) is strongly implicated in a plethora of diseases that are associated with maladaptive immune responses. On the other hand, several evidence imply that dysregulated immune activity (e.g. excessive inflammation) may alter/disrupt the proper functioning of peripheral clocks. This knowledge paves the way to the exploitation of chronobiological concepts in clinical practice. A better comprehension of various transcriptional/translational and biochemical mechanisms that maintain rhythmicity in immune system activities, as well as the many factors (host-derived, microbiota-derived, environment) that can alter or disrupt these processes, will facilitate the development of novel chrono-immunotherapeutic approaches.