Electrochemical impedance spectroscopy (EIS) provides valuable insights into the interfacial kinetics and mass-transport behavior of an electrochemical system. However, conventional steady-state EIS cannot sufficiently capture transient processes in enzymatic biofuel cells (EBFCs), wherein electrode/electrolyte interactions evolve dynamically. In this study, we demonstrate a multi-in situ impedance method applicable to glucose/O2 EBFCs that employ MgO-templated carbon electrodes. Chronopotentiometry reveals that lower current densities induce higher glucose utilization efficiencies, reflecting the balance between the rates of substrate diffusion and surface reactions. In situ impedance analysis further differentiates the electrode-specific degradation: the cathode exhibits progressively increasing charge-transfer resistance attributable to enzyme and mediator leaching, whereas the anode displays non-monotonic resistance changes linked to overpotential-driven kinetics. Equivalent circuit modeling confirms that the cathodic overpotential is responsible for accelerating charge-transfer processes, leading to smaller semicircular features in the Nyquist plot over time. These results highlight the utility of multi-impedance measurements in identifying the performance-limiting factors in an EBFC under operational conditions. This approach provides mechanistic insights into enzyme stability, mediator retention, and substrate transport, and it serves as a diagnostic tool for the rational design of next-generation bioelectrochemical energy devices.
There is a concept called Ecofitting technology. It is a concept that making industrial processes more environmentally friendly leads to a transformation into a more economical industrial process as a result. I have developed several new chemical processes based on this research concept. One of them is the radical vapor reactor (RVR), which is already in practical use (commercially available) as a process device. I found and developed a reaction (called the oxygen P/L reaction or RVR reaction) that can generate high concentrations of hydroxyl radicals and singlet oxygen, which are highly oxidizing among reactive oxygen species, and developed a device that can expose objects to the high-concentration reactive oxygen atmosphere generated by the reaction. I have then put it into practical use as a reactive oxygen species generation and exposure device that can be used in various chemical industrial processes. In this paper, the author, who discovered the RVR reaction, developed the RVR device, and further demonstrated various applications of the RVR, outlines the research and development of the RVR reaction (device design and commercialization), and examples of applications of the commercialized RVR device.
The primary objective of this study is to assess the adsorption behavior of boron using a tannin-based biosorbent known as tannic acid resin, synthesized from Turkish acorns (valonia) through the spray-drying method. The resulting biosorbent, named Valex, underwent modification into a tannic acid resin-based structure, rendering it suitable for use as a biosorbent. Comprehensive characterization studies involving Fourier transform infrared, X-ray diffraction, scanning electron microscopy, and Brunauer-Emmett-Teller analysis were conducted on this biosorbent. The outcomes demonstrated the effectiveness of tannic acid resin, a tannin-based biosorbent, in removing boron from aqueous solutions. Various parameters such as pH, initial boron concentration, and adsorbent dosage were investigated for their impact on boron removal. The study also delved into adsorption kinetics, adsorption isotherm models, and adsorption thermodynamics. Maximum boron removal, reaching 92.9%, was achieved using 1 g of tannic acid resin-based biosorbent with an initial boron concentration of 8 mg L −1 within 6 h at pH 3. The Langmuir, Freundlich, Dubinin–Radushkevich, and Temkin isotherm models were applied to experimental data, with the Temkin model demonstrating a good fit. Adsorption kinetics were explored using pseudo-first-order, pseudo-second-order, Elovich, first-order, second-order, and intraparticle diffusion models, with the pseudo-second-order kinetic model fitting the data effectively. The negative values of Δ G ° at all temperatures indicated the spontaneous nature of boron adsorption on the tannin resin, and the positive value of Δ H ° suggested the endothermic nature of adsorption. This study shows the efficacy of Valex in boron adsorption and suggests its potential application as an effective method for boron removal. This study's findings on the impact of various parameters on boron removal provide insights for optimizing the boron adsorption process in practical applications.
When using a wrench, the nut is easily damaged due to improper operation or impact. Although coating a polymer layer on the surface of the wrench can effectively solve the above problem, the layer is easy to be deboned due to the lack of adhesion between the polymer and the surface of the wrench. Herein, we implemented an anodizing treatment strategy on the surface of the wrench to obtain a porous oxide film. Interestingly, during the anodization process, micro-nanopores with a specific diameter can be obtained by adjusting the voltage, temperature, and electrolyte concentration. Furthermore, the ammonium fluoride/ethylene glycol electrolyte was used to etch the formed large hole to form the large hole sleeve small hole structure. In order to inject polyphenylene sulfide (PPS) molecules into multiscale holes to form a pinning effect, we also used nano molding technology to inject PPS into the metal surface. The results showed that the adhesion between PPS and the wrench was greatly improved compared with the commonly used dip coating method.
Approximate density‐functional theory (DFT) has become the major workhorse of modern computational chemistry and materials science, but the most widely used DFT approaches, local‐density approximation (LDA) and generalized gradient approximation (GGA), suffer from some fundamental deficiencies, including, in particular, the band gap problem. As a relatively cheap way to overcome the difficulty confronted by LDA/GGA, hybrid functional methods have attracted tremendous interest, first in molecular quantum chemistry, and more recently also in computational materials science. While early hybrid functionals use fixed parameters that are determined either by fitting some standard experimental database or based on theoretical arguments, recent studies have clearly indicated that the hybridization parameters carry on the physical significance and therefore should be system‐dependent. Developing theoretical methods to evaluate those parameters in a first‐principles manner has become one of the most active frontiers in theoretical chemistry community, and various schemes have been proposed. In this article, we aim at giving a systematic overview on the main theoretical concepts underlying various strategies and review major methodological developments in the recent years.
Progress in the synthesis, design, and characterisation of single-molecule magnets (SMMs) has expanded dramatically from curiosity driven beginnings to molecules that retain magnetization above the boiling point of liquid nitrogen. This is in no small part due to the increasingly collaborative nature of this research where synthetic targets are guided by theoretical design criteria. This article aims to summarize these efforts and progress from the perspective of a synthetic chemist with a focus on how chemistry can modulate physical properties. A simple overview is presented of lanthanide electronic structure in order to contextualize the synthetic advances that have led to drastic improvements in the performance of lanthanide-based SMMs from the early 2000s to the late 2010s.
The topic of heavier main group compounds possessing multiple bonds is the subject of momentous interest in modern organometallic chemistry. Importantly, there is an excitement involving the discovery of unprecedented compounds with unique bonding modes. The research in this area is still expanding, particularly the reactivity aspects of these compounds. This article aims to describe the overall developments reported on the stable derivatives of silicon and germanium involved in multiple bond formation with other group 13, and heavier groups 14, 15, and 16 elements. The synthetic strategies, structural features, and their reactivity towards different nucleophiles, unsaturated organic substrates, and in small molecule activation are discussed. Further, their physical and chemical properties are described based on their spectroscopic and theoretical studies.
The binding of malaria pigment, hemozoin, by a gradient magnetic field has been investigated in a manual trapping column system. Two types of magnetic filling have been tested to produce field gradients: nickel-plated steel wires, wrapped around a steel core, and superparamagnetic microbeads. The latter system allows an efficient trapping (> 80%) of β-hematin (a synthetic pigment with physical and paramagnetic properties analogous to those of hemozoin). Tests with a Plasmodium falciparum 3D7 culture indicate that hemozoin is similarly trapped. Off-line optical spectroscopy measurements present limited sensitivity as the hemozoin we detected from in vitro cultured parasites would correspond to only a theoretical 0.02% parasitemia (1000 parasites/µL). Further work needs to be undertaken to reduce this threshold to a practical detectability level. Based on these data, a magneto-chromatographic on-line system with reduced dead volumes is proposed as a possible low-cost instrument to be tested as a malaria diagnosis system.
Three-dimensional models based on polylactide containing 1 and 5% hydroxyapatite were obtained by the method of fused deposition. In vitro testing showed that a surface modification of the polymer models with 4% hydroxyapatite gel or an aqueous suspension containing 4% polyvinyl alcohol and 4% hydroxyapatite can improve bioactive properties of such materials.