For effective and large-scale water electrolysis aimed at green hydrogen generation, the construction of efficient catalytic electrodes for both cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER) is critical. This process can further benefit by replacing the sluggish OER with tailored electrooxidation of certain organics, enabling a more energy-efficient and safer co-production of hydrogen and value-added chemicals. Electrodeposited onto a Ni foam (NF) substrate, amorphous Ni-Co-Fe ternary phosphides (NixCoyFez-Ps) with varying NiCoFe ratios were employed as self-supporting catalytic electrodes for alkaline hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The Ni4Co4Fe1-P electrode, deposited in a solution having a NiCoFe ratio of 441, exhibited a low overpotential (61 mV at -20 mA cm-2) and acceptable durability for the hydrogen evolution reaction. Simultaneously, the Ni2Co2Fe1-P electrode, synthesized in a deposition solution maintaining a NiCoFe ratio of 221, showcased a superior oxygen evolution reaction (OER) efficiency (275 mV overpotential at 20 mA cm-2) and substantial durability. This substitution of the OER with the anodic methanol oxidation reaction (MOR) facilitated selective formate production, exhibiting a 110 mV reduction in anodic potential at 20 mA cm-2. The HER-MOR co-electrolysis system, employing a Ni4Co4Fe1-P cathode and a Ni2Co2Fe1-P anode, demonstrates a remarkable 14 kWh per cubic meter of H2 energy savings compared to conventional water electrolysis. Rational electrode design and a co-electrolysis setup form the basis of this work's feasible strategy for co-producing hydrogen and enhanced formate using energy-efficient methods. This approach opens up potential for economically viable co-production of higher-value organics and environmentally friendly hydrogen using electrolysis.
Within the realm of renewable energy systems, the Oxygen Evolution Reaction (OER) has achieved significant prominence due to its crucial function. The quest for economical and low-cost open educational resource catalysts presents a significant and compelling challenge. This work details the potential of phosphate-incorporated cobalt silicate hydroxide (CoSi-P) as an electrocatalyst for the oxygen evolution reaction. Researchers first synthesized hollow spheres of cobalt silicate hydroxide, specifically Co3(Si2O5)2(OH)2 (denoted as CoSi), using SiO2 spheres as a template, employing a facile hydrothermal method. The layered CoSi system, subjected to phosphate (PO43-) treatment, caused the hollow spheres to restructure themselves into sheet-like morphologies. Consistent with projections, the resulting CoSi-P electrocatalyst manifested a low overpotential (309 mV at 10 mAcm-2), a significant electrochemical active surface area (ECSA), and a low Tafel slope. These parameters demonstrate superior performance compared to CoSi hollow spheres and cobaltous phosphate (denoted as CoPO). Subsequently, the catalytic activity at a current density of 10 mA per cm² exhibits a performance that is comparable to, or exceeds, that of the vast majority of transition metal silicates, oxides, and hydroxides. Phosphate's inclusion in the CoSi composition is found to heighten the catalyst's oxygen evolution reaction efficacy. Beyond introducing the CoSi-P non-noble metal catalyst, this study showcases the promising approach of incorporating phosphates into transition metal silicates (TMSs) for designing robust, high-efficiency, and low-cost OER catalysts.
The production of H2O2 via piezocatalysis has garnered significant interest as a sustainable alternative to conventional anthraquinone processes, which often entail significant environmental contamination and high energy expenditures. Although the efficiency of piezocatalysts in producing hydrogen peroxide (H2O2) is presently insufficient, a dedicated effort to discover an improved methodology for augmenting H2O2 yield is warranted. This study investigates the use of graphitic carbon nitride (g-C3N4) materials with various morphologies, including hollow nanotubes, nanosheets, and hollow nanospheres, to improve the piezocatalytic yield of H2O2. The hollow g-C3N4 nanotube exhibited a remarkable 262 μmol g⁻¹ h⁻¹ hydrogen peroxide generation rate, demonstrating a 15-fold and a 62-fold enhancement compared to nanosheet and hollow nanosphere performance, respectively, in the absence of any co-catalyst. Piezoelectrochemical tests, piezoelectric response force microscopy, and finite element simulations confirm that the excellent piezocatalytic performance of hollow nanotube g-C3N4 is primarily attributable to its superior piezoelectric constant, high intrinsic charge density, and robust external stress absorption and conversion mechanisms. Subsequently, examining the mechanism revealed a two-step single-electrochemical pathway for piezocatalytic H2O2 production, and the discovery of 1O2 opens up new avenues for investigating the process. This research unveils a novel eco-friendly method for H2O2 production and a valuable guide for future inquiries into morphological engineering in piezocatalytic systems.
Supercapacitor technology, an electrochemical energy-storage method, represents a potential solution for satisfying the green and sustainable energy needs of the future. Medically Underserved Area However, the limited energy density hampered practical use cases. In order to overcome this limitation, we constructed a heterojunction system consisting of two-dimensional graphene and hydroquinone dimethyl ether, a unique redox-active aromatic ether. The heterojunction exhibited a substantial specific capacitance (Cs) of 523 F g-1 at a current density of 10 A g-1, along with noteworthy rate capability and cycling stability. In the case of symmetric and asymmetric two-electrode architectures, supercapacitors demonstrate voltage windows of 0-10 volts and 0-16 volts, respectively, while exhibiting noteworthy capacitive characteristics. A superior device delivers an energy density of 324 Wh Kg-1 and a power density of 8000 W Kg-1, yet unfortunately exhibited a slight capacitance decrement. The device's sustained performance was characterized by low self-discharge and leakage current during extended use. This strategy's potential lies in motivating investigation into aromatic ether electrochemistry and facilitating the development of EDLC/pseudocapacitance heterojunctions, thereby promoting critical energy density enhancement.
Due to the increasing bacterial resistance, high-performing and dual-functional nanomaterials that simultaneously fulfill the requirements of bacterial detection and eradication are critically important, but their design remains a considerable obstacle. Newly developed and fabricated for the first time, a 3D hierarchically structured porous organic framework, PdPPOPHBTT, was rationally designed to simultaneously detect and eradicate bacteria. The PdPPOPHBTT system facilitated the covalent integration of palladium 510,1520-tetrakis-(4'-bromophenyl) porphyrin (PdTBrPP), a prime photosensitizer, with 23,67,1213-hexabromotriptycene (HBTT), a 3D building unit. Agrobacterium-mediated transformation The resultant material exhibited remarkable near-infrared (NIR) absorption, a narrow band gap, and a strong capacity for singlet oxygen (1O2) production. This characteristic is essential for the sensitive detection and effective removal of bacteria. A colorimetric method successfully detected Staphylococcus aureus and efficiently eliminated both Staphylococcus aureus and Escherichia coli. First-principles calculations, performed on highly activated 1O2 structures derived from 3D conjugated periodic structures, revealed ample palladium adsorption sites within PdPPOPHBTT. The bacterial infection wound model, assessed in vivo, showed that PdPPOPHBTT exhibited superior disinfection capabilities with a negligible side effect on surrounding normal tissue. This research offers a groundbreaking strategy for the development of individual porous organic polymers (POPs) with diverse functionalities, consequently extending the range of applications of POPs as potent non-antibiotic antimicrobial agents.
Vulvovaginal candidiasis (VVC) is a vaginal infection, characterized by the abnormal growth of Candida species, especially Candida albicans, within the vaginal mucosal layer. Vulvovaginal candidiasis (VVC) displays a marked shift in the composition of its vaginal flora. Lactobacillus's presence is a key component in the maintenance of vaginal health. Despite this, several studies have demonstrated the resistance of Candida species to various interventions. For VVC treatment, azole drugs are recommended, and they effectively combat the related microorganisms. To address vulvovaginal candidiasis, the probiotic properties of L. plantarum could be utilized as an alternative. 1-Thioglycerol mw To achieve their therapeutic benefits, probiotics require sustained viability. By employing a multilayer double emulsion approach, microcapsules (MCs) containing *L. plantarum* were formulated, consequently enhancing their viability. A revolutionary vaginal drug delivery system, utilizing dissolving microneedles (DMNs), was created to treat vulvovaginal candidiasis (VVC) for the first time. The demonstrable mechanical and insertion properties of these DMNs, along with their rapid dissolution upon insertion, enabled efficient probiotic release. Scientific analysis confirmed that all formulated products were non-irritating, non-toxic, and safe when used on the vaginal mucosal membrane. Essentially, DMNs demonstrated a growth-inhibitory effect on Candida albicans, showing a 3-fold reduction in growth compared to hydrogel and patch treatments in the ex vivo infection model. Thus, this study successfully developed the multilayered double emulsion-based formulation of L. plantarum-loaded microcapsules which are further incorporated into DMNs for vaginal delivery, to address the issue of vaginal candidiasis.
The escalating need for high-energy resources is accelerating the development of hydrogen as a clean fuel, facilitated by the process of electrolytic water splitting. For the production of renewable and clean energy, exploring high-performance and cost-effective electrocatalysts for water splitting poses a significant challenge. The oxygen evolution reaction (OER)'s sluggish kinetics presented a major obstacle to its practical application. A novel electrocatalyst, comprising oxygen plasma-treated graphene quantum dots embedded Ni-Fe Prussian blue analogue (O-GQD-NiFe PBA), is suggested herein for its high activity in oxygen evolution reactions.