Chemical Stability Properties Research Articles

Facile modification of sepiolite and its application in wear-resistant and superhydrophobic epoxy coatings by mimicking the structure of shark skin

Superhydrophobic surfaces have demonstrated significant potential in various fields. Nonetheless, creating durable superhydrophobic surfaces with practical application value remains a major challenge. This study utilizes biomimicry to prepare a series of composites similar to shark skin, which possesses hydrophobic and wear-resistant properties. A dual-coating strategy was developed to create a durable and wear-resistant superhydrophobic surface. This article introduces a novel approach by incorporating chemically modified sepiolite and graphite nanoparticles in a layer-by-layer composite for enhancing wear resistance in epoxy resin coatings. Epoxy resin (EP) was used as the matrix material, graphite nanoparticles (GNP) were incorporated for the wear-resistant layer, and modified superhydrophobic Sepiolite (osSep) particles were utilized for the superhydrophobic layer. Both of these layers could form hydrogen bonds with epoxy resin, leading to a functional coating that offers wear resistance, superhydrophobicity, chemical stability, and self-cleaning properties. This article applies EP@GNP@osSep composites to glass, wood, and stainless steel mesh, imparting excellent superhydrophobic properties, wear resistance, self-cleaning abilities, and anti-staining properties. The superhydrophobic coating prepared in this manuscript can meet the requirements of robustness and superhydrophobicity for various materials, with promising market potential.

Intrinsically Microporous Polyimides Based on a Rigid-Soft Structure for Hydrogen Separation.

Polyimide (PI)-based gas separation membranes are of great interest in the field of H2 purification owing to their good thermal stability, chemical stability, and mechanical properties. Among polyimide-based membranes, intrinsically microporous polyimides are easily soluble in common organic solvents, showing great potential for fabricating hollow fiber gas separation membranes. However, based on the solution-diffusion model, improving the free volume or the movability of polymer chains can improve gas permeability, but would result in poor thermal stability. Herein, we develop a carbazole-alkyl-based diamine monomer that endows PI chains with a "rigid-soft" structure to balance the trade-off between them. Soft units enhance the movability of polymer chains during the film-forming process, ensuring that rigid units achieve tight chain packing and strong intermolecular interactions. Meanwhile, bulky carbazole groups could further restrict the motion of soft units in the solid state. On the one hand, it restricts the movability of the polymer chains below Tg, enhancing the small gas selectivity for H2 and He. On the other hand, it ensures good thermal stability. Moreover, extending the length of the alkyl chains helps improve the free volume and intermolecular interactions simultaneously, thereby further optimizing the gas permeability/selectivity trade-off. As a result, the as-prepared PI shows H2 permeability of 89.61 Barrer, H2/CH4 selectivity of 87.85, and H2/N2 selectivity of 45.03 in contrast to the reference FPI TFMB-6FDA exhibiting H2 permeability of 92.95 Barrer, H2/CH4 selectivity of 72.62, and H2/N2 selectivity of 38.57. Meanwhile, a high Tg value of 334 °C is also achieved.

Enhanced production of bacterial cellulose with a mesh dispenser vessel-based bioreactor

Abstract Bacterial cellulose (BC) has gained significant interest for various applications due to its useful properties which include chemical stability and strong physical properties as well as its biocompatibility. However, conventional fabrication methods are limited by a lack of control over the form, particularly depth and thickness, restricting BC applications to 2D planar shapes. The production of BC is constrained by the formation of a pellicle at the liquid–air interface. To overcome this constraint and enable continuous pellicle formation, a method was established to combine intermittent batch feeding with a supportive mesh scaffold. Intermittent feeding supplies nutrients to the pellicle, promoting sustained formation at the liquid–air interface, while the supporting mesh anchors the initial pellicle to prevent submersion. This approach facilitates the continuous growth of BC pellicle at a controlled rate. Moreover, the method described here results in a single BC pellicle with enhanced thickness, weight (both wet and dry states), water-holding capacity and mechanical strength. Continuous growth is achievable with ongoing nutrient supply, allowing for precise control over the final pellicle thickness. This culturing method is scalable and has been tested for volumes ranging from 250 mL to 10 L, and significantly increases glucose-to-cellulose conversion (3.4-fold) and water utilization efficiency (2.4-fold).

Preparation of sulfur-doped porous carbon from polyphenylene sulfide waste for photothermal conversion materials to achieve solar-driven water evaporation.

In recent years, solar-driven photothermal water evaporation technology for seawater desalination and wastewater treatment has developed rapidly, which is of great significance for addressing the issue of freshwater scarcity. However, due to the high costs associated with the manufacturing, maintenance, and operation of such devices, their application remains challenging in remote and resource-scarce regions. Due to its excellent light absorption capability in the near-infrared region, high hydrophilicity, and stable chemical properties, coupled with the low cost of recycling waste carbonized polyphenylene sulfide, this material is an excellent choice as a photothermal material for solar-driven water evaporation devices. Ordinary wood in nature usually has a highly regenerative porous structure, which is a natural water transport channel that facilitates the transport of water from the bottom to the top, allowing it to be rapidly converted into vapor. Based on this characteristic, this article innovatively proposes to prepare waste polyphenylene sulfide from porous carbonized materials (KCP) as the photothermal conversion material for novel photothermal water evaporation devices, achieving solar-driven water evaporation. This material efficiently facilitates the conversion between solar and thermal energies and exhibits excellent hydrophilicity, thereby enabling the rapid utilization of absorbed solar energy for water evaporation on the surface of the evaporator. In this study, a porous carbonized polyphenylene sulfide photothermal water evaporator (KCP-wood) was fabricated by using freeze-drying and in situ coating to load the photothermal conversion material onto a wood substrate. Under simulated one-sun irradiation, this evaporator achieved a water evaporation rate of 2.41 kg m-2 h-1 and a photothermal conversion efficiency of 91.3%. Additionally, a systematic study was conducted on the photothermal performance of various light-water evaporators, encompassing photothermal conversion efficiency, stability, thermal conductivity, and anti-fouling capabilities. Finally, the practical performance of the light-water evaporator under various environmental conditions was validated, demonstrating its excellent stability and durability. It is capable of effectively applying to high-efficiency water resource utilization and solar energy conversion fields.

Rapid Development of High Concentration Protein Formulation Driven by High-Throughput Technologies.

High concentration protein formulation (HCPF) development needs to balance protein stability attributes such as conformational/colloidal stability, chemical stability, and solution properties such as viscosity and osmolality. A three-phase design is established in this work. In Phase 1, conformational and colloidal stability are measured by 384-well-based high-throughput (HT) biophysical screening while viscosity reduction screening is performed with HT viscosity screening. Collectively, the biophysical and viscosity screening data are leveraged to design the phase 2 of short-term stability study, executed using 96-well plates under thermal and freeze/thaw stresses. In phase 2, samples are analyzed by stability-indicating assays and processed with pair-wise Student's t-test analyses to choose the final formulations. In phase 3, the final formulations are then confirmed through a one-month accelerated stability in glass vials. Using a model antibody A (mAb-A), the initial HT screening successfully established the 384-well based platform. A lead formulation was chosen from the second round based on statistical analyses and subsequently tested against the commercial formulation of mAb-A as a control. Compared to the control, the lead formulation reduced the viscosity of mAb-A by 30% and decreased subvisible particles after thermal stress by 80%. HT biophysical screening in 384-well plates was demonstrated to effectively guide the rational design of a high-throughput stability screening study using 96-well plates. This platform enables the identification of a high concentration formulation within seven weeks within the first two phases of study that strategically balance stability with solution properties, thus achieving a rapid development of HCPF.

A Comprehensive Review of Niobium Nanoparticles: Synthesis, Characterization, Applications in Health Sciences, and Future Challenges.

Niobium nanoparticles (NbNPs) have gained attention as promising materials in biomedical applications due to their exceptional biocompatibility, corrosion resistance, and versatility. These nanoparticles offer potential in drug delivery, imaging, and tissue engineering, where their nanoscale properties allow precise interactions with biological systems. Among niobium-based nanomaterials, niobium pentoxide (Nb2O5) is the most extensively studied due to its chemical stability, bioactivity, and optical properties. Nb2O5 nanoparticles have shown significant potential in catalysis, biosensing, and photodynamic therapy, as their stability and reactivity make them ideal for functionalization in advanced biomedical applications. Despite these advantages, challenges remain regarding the biodegradability and long-term retention of NbNPs in biological systems. Their accumulation in tissues can lead to risks such as chronic inflammation or toxicity, emphasizing the importance of designing nanoparticles with controlled clearance and biodegradability. Surface modifications, such as coatings with biocompatible polymers, have demonstrated the ability to mitigate these risks while enhancing therapeutic efficacy. This review provides a comprehensive overview of NbNPs, with a focus on Nb2O5, highlighting their unique properties, current biomedical applications, and limitations. By addressing the remaining challenges, this work aims to guide the development of safer and more effective niobium-based nanomaterials for future medical innovations.

Synthesis of core–shell structured Cu2O@Co(OH)2 anchored on three-dimensional macroporous carbon for efficient non-enzymatic glucose detection

Transition metal oxides and hydroxides have gained significant attention from researchers due to their abundance, low cost, and stable chemical properties. In this study, a straightforward and efficient method was used to anchor Cu2O onto a three-dimensional macroporous carbon (MPC) framework. The Cu2O/MPC template was then etched, allowing for the growth of a cobalt hydroxide layer on the surface of Cu2O nanocubes. The resulting Cu2O@Co(OH)2/MPC composite provides a conductive carbon skeleton that promotes electron transfer, while its core–shell structure increases the specific surface area, enhancing the material’s electrocatalytic activity. The sensor demonstrates a broad linear range (0.3 to 1937.3 μM), high sensitivity (0.776 μA mM−1 cm−2), and a low limit of detection (0.124 μM), offering a promising new approach for non-enzymatic glucose detection. This work contributes to the development of a simple and highly sensitive non-enzymatic glucose sensor.

Application of advanced quantum dots in perovskite solar cells: synthesis, characterization, mechanism, and performance enhancement.

Quantum dots have garnered significant interest in perovskite solar cells (PSCs) due to their stable chemical properties, high carrier mobility, and unique features such as multiple exciton generation and excellent optoelectronic characteristics resulting from quantum confinement effects. This review explores quantum dot properties and their applications in photoelectronic devices, including their synthesis and deposition processes. This sets the stage for discussing their diverse roles in the carrier transport, absorber, and interfacial layers of PSCs. We thoroughly examine advances in defect passivation, energy band alignment, perovskite crystallinity, device stability, and broader light absorption. In particular, novel approaches to enhance the photoelectric conversion efficiency (PCE) of quantum dot-enhanced perovskite solar cells are highlighted. Lastly, based on a comprehensive overview, we provide a forward-looking outlook on advanced quantum dot fabrication and its impact on enhancing the photovoltaic performance of solar cells. This review offers insights into fundamental mechanisms that endorse quantum dots for improved PSC performance, paving the way for further development of quantum dot-integrated PSCs.

A vinylene-linked diketopyrrolopyrrole-based covalent organic framework for photocatalytic oxidation reactions.

A vinylene-linked DPP-COF with an ultra-narrow bandgap of 1.06 eV was reported. This COF demonstrates high chemical stability and significant charge transfer properties, and was applied to the photooxidation of sulfides and tetrahydroisoquinolines, exhibiting exceptional photoactivities.

Research Progress on the Application of Nanocellulose in Glucose Sensing.

Nanocellulose is not only a biocompatible and environmentally friendly material but also has excellent mechanical properties, biodegradability, and a large number of hydroxyl groups that have a strong affinity for water. These characteristics have attracted significant attention from researchers in the field of glucose sensing. This review provides a brief overview of the current research status of traditional materials used in glucose sensors. The sensing performance, chemical stability, and environ-mental properties of nanocellulose-based glucose sensors are compared and summarized based on the three sensing methods: electrochemical sensing, colorimetric sensing, and fluo-rescence sensing. The article focuses on recent strategies for glucose sensing using nanocel-lulose as a matrix. The development prospects of nanocellulose-based glucose sensors are also discussed. Nanocellulose has outstanding structural characteristics that contribute signifi-cantly to the sensing performance of glucose sensors in different detection modes. However, the preparation process for high-quality nanocellulose is complicated and has a low yield. Furthermore, the sensitivity and selectivity of nanocellulose-based glucose sensors require further improvement.

Cold sintering of geopolymer powders

AbstractGeopolymers (GP) represent a promising class of inorganic materials with diverse applications due to their properties, including high temperature resistance and strong interfacial bonding ability. They are produced through alkali activation of aluminosilicate sources, such as metakaolin or fly ashes. Despite their attractive characteristics, conventional casting methods for GP production often result in prolonged curing times and inferior mechanical properties to OPC or other benchmark materials. In this study, we investigated the feasibility of rapidly densifying GP matrices using cold sintering technology (CSP), a novel approach previously employed in ceramic systems. Through CSP, it was possible to obtain a dense body starting from GP sodium‐based powder with optimal moisture content (10% wt.) under mild isostatic pressure (70 MPa) and moderate temperature (150°C) conditions, with a short duration process (10 min). The resulting products exhibited chemical stability (high resistance to boiling test), high density (> 90% theoretical density) and good mechanical properties (flexural strength equal to 30 MPa and compressive strength over 200 MPa) without requiring additional thermal treatments. SEM, EDS and NMR studies indicated that the predominant densification mechanism was likely to be homogeneous dissolutions and precipitation of the material, consistent with pressure solution creep. Dilatometric tests were performed to track the densification process in real‐time and to determine the activation energy, which revealed an exceptionally low value for the system (21.7 kJ/mol). Our results demonstrate the potential of CSP as a rapid and efficient method for producing high‐quality GP‐based components, paving the way for their broader application in various fields.

Organogel Polymer Electrocatalysts for Two-Electron Oxygen Reduction.

Polymer gels, renowned for unparalleled chemical stability and self-sustaining properties, have garnered significant attention in electrocatalysis. Notably, organic polymer gels that exhibit temperature sensitivity and incorporate suitable polar nonvolatile liquids, enhance electronic conductivity, and impart distinct morphological features, but remain largely unexplored as electrocatalysts for oxygen reduction reaction (ORR). To address this issue, an innovative strategy is proposed for synergistic modulation of the rigidity of mainchain molecular skeleton and length of alkyl sidechains, enabling the development of organogel polymers with a sol-gel temperature-sensitive phase transition that promises high selectivity and enhanced activity in electrocatalytic processes. Notably, the shortening of alkyl sidechain length can significantly affect the gelation behavior and internal microstructure of the catalyst, which modifies the electron state, ultimately impacting the catalytic activity of the gel polymer catalysts. In particular, phenyl-containing Ph-FL1 with short alkyl sidechains demonstrates outstanding 2e- ORR activity in alkaline medium, achieving a remarkable hydrogen peroxide (H2O2) selectivity of 98.6% with an impressive yield of 4.08 mol g-1 h-1. This performance surpasses most metal-free carbon-based electrocatalysts. Through theoretical calculation, the carbon atom (site-3) of C═N group is identified as potential active sites, representing a significant advancement toward designing cost-effective and efficient ORR electrocatalysts.

Unveiling the Origin of the Strengthening Mechanism in a Novel Precious Metal Multi-Principal Elements Alloy.

Precious metal electrical contact materials are pivotal in microelectronic devices due to their excellent chemical stability and electrical properties. Their practical application is hindered by the strength, contact resistance, and high cost. Multi-principal elements alloys (MPEAs) provide the possibility to develop cost-effective materials with enhanced mechanical properties. To address this, a novel precious metal MPEA, PdAgCuAuPtZn alloy, is designed, which exhibits significant solid solution strengthening and aging strengthening effects. The ultimate tensile strength increases from 747MPa in the solution state to 1126MPa in the aged state, while resistivity remains low. This study presents the first systematic investigation into the strengthening mechanisms of precious metal MPEAs using nanoindentation technology. These findings indicate that the aging strengthening of the alloy is attributed to spinodal decomposition (SD) and chemical short-range order (CSRO) in the matrix. Furthermore, the precipitation structure with Cu-rich and Ag-rich phases gradually replaces the matrix, primarily accounting for aging softening. Additionally, it is discovered that precipitation structure can be strengthened by CSRO formed in the Cu-rich phase, thus providing an innovative strengthening in PdAgCuAuPtZn alloy. These results will be beneficial to both deeply understanding the aging behaviors of PdAgCuAuPtZn alloys and designing high-performance precious metal MPEAs.

A Comprehensive Review of MXene-Based Emerging Materials for Energy Storage Applications and Future perspectives.

MXenes is a rapidly emerging class of two-dimensional (2D) materials. It exhibits unique properties that make it suitable for a wide range of applications. This review provides a comprehensive overview of the synthesis and processing techniques for MXenes including both bottom-up and top-down approaches. The synthesis of MXene-based composites is explored in detail focusing on MXene-carbon composites, MXene-metal oxides, MXene-metal sulfides, MXene-polymer composites and MXene-ceramic composites. Key properties of MXenes are examined including structural, electrical, morphological, optical, mechanical, chemical stability, electrical and thermal properties, conductivity, magnetic properties, dielectric charge and catalytic properties. Characterization techniques used to study these properties are also reviewed. Their 2D structure provides a high surface area and unique interlayer spacing, making MXenes ideal for applications in energy storage devices (like supercapacitors and batteries) where surface area and ion transport are critical for performance. The diverse applications of MXenes are presented emphasizing their use in batteries, catalysis, sensors, environmental remediation and supercapacitors. Special attention is given to the supercapacitor applications of MXenes of their potential in energy storage devices. Due to their high capacitance, fast charge/discharge rates, and excellent stability, MXenes are used in supercapacitors, lithium-ion batteries, and sodium-ion batteries.

Current Advances in Synthesis and Therapeutic Applications of Thiazole and its Derivatives

Thiazole, a five-membered heterocyclic compound with sulfur and nitrogen atoms, serves as a fundamental scaffold in medicinal chemistry. The aromatic nature and diverse substitution patterns of the thiazole ring system enable its extensive applications in drug development. Multiple synthetic routes, from classical Hantzsch synthesis to modern methods, yield varied thiazole derivatives under specific reaction conditions. The biological importance of thiazole-containing compounds extends to anticancer, antimicrobial, and antidepressant activities. Several thiazole-based drugs have demonstrated significant therapeutic effects - dasatinib and dabrafenib as antitumor agents target specific kinases to inhibit cancer cell growth, while ampicillin and myxothiazole exhibit broad-spectrum antimicrobial properties. Structure-activity relationship studies have revealed that substituents at different positions of the thiazole ring significantly influence the biological activity. For instance, attachment of thiourea linker at position 2 enhances anticancer properties, while aryl/alkyl substitutions affect chemical stability and pharmacokinetic properties. The mechanistic understanding of thiazole-based compounds has led to targeted drug development. Recent synthetic methods have produced novel thiazole derivatives with enhanced therapeutic properties, particularly in antimalarial activity where thiazolyl benzenesulfonamide carboxylates show promising results against Plasmodium falciparum

Carbon plastics for reusable hypersonic flight vehicles

The development of hypersonic unmanned aerial vehicles (UAVs) for aerospace systems presents ambitious challenges for scientists and engineers. Extreme flight conditions, such as ultra-high speeds and significant aerodynamic heating, necessitate the creation of new materials capable of withstanding such loads. One of the most promising materials for constructing hypersonic UAVs is carbon fiber-reinforced polymer based on bisphenol nitrile. This material exhibits high thermal resistance, chemical stability, and excellent mechanical properties. Utilizing bisphenol nitrile combined with carbon fibers has enabled the production of composite materials that can operate at temperatures exceeding 3000C, far surpassing the capabilities of traditional polymer matrices. To assess the suitability of the developed carbon fiber-reinforced plastic for hypersonic UAV applications, comprehensive studies of its physical, mechanical, and thermal characteristics were conducted across a wide temperature range from 20 to 3000C. The obtained results provided a detailed characterization of the composite and allowed for comparisons with other high-temperature composite materials. The developed carbon fiber-reinforced plastic based on bisphenol nitrile binder shows great promise for constructing hypersonic UAVs. Its high thermal resistance, combined with excellent mechanical properties, makes it suitable for use in the extreme temperature conditions typical of hypersonic flight.

Effect of modified investment and casting system on the recasting properties of high-gold alloy

Background/purposeHigh gold (Au) alloys have many advantages, such as good mechanical properties and stable chemical properties for dental restoration. The purpose of this investigation was to investigate the effect of zirconia (ZrO2)-magnesia (MgO)-based investment combined with an argon arc vacuum pressure (Ar-arc VP) casting process on the recasting of high Au alloys. Materials and methodsThe recasting Au alloys were compared between the control group of conventional SiO2-based investment/horizontal centrifugal (HC) casting and the experimental group of ZrO2–MgO-based investment/Ar-arc VP die casting. The first-generation castings were defined as being made from purchased Au alloys and the second-generation castings were made from 50 wt% of the original Au alloys before casting, plus the balance of the remaining 50 wt% from the previous castings. The third-generation was made from all old surplus from the previous castings. The ingots were measured for the marginal gap, surface roughness, interface oxidation, hardness, and phase identification. ResultsThe results showed that the recasting success rate reached 100%. The ZrO2–MgO-based investment/Ar-arc VP group had better edge precision, smaller oxide layer thickness, and lower hardness than the SiO2-based investment/HC group. However, surface roughness analysis indicated little difference between the two groups. Phase analysis showed that the recasting alloys of the second and third-generation groups contained higher Au contents than those of the first-generation. ConclusionOverall, the Au alloy can be better recasted and retain good mechanical properties under the clinically used 5 wt% ZrO2–MgO-based investment/Ar-arc VP casting method.

Bi2S3/BiOCl heterojunction-based photoelectrochemical aptasensor for ultrasensitive assay of fumonisin B1 via signal amplification with in situ grown Ag2S quantum dots.

Fumonisin B1 (FB1) is a mycotoxin mainly found in corn, peanuts, and wheat crops, which affects human health.Based on bismuth sulfide/bismuth oxychloride (Bi2S3/BiOCl) composite material, silver sulfide (Ag2S) was grown in situ as a quantum dot sensitization signal, and a photoelectrochemical (PEC) aptasensor was designed by layer upon layer modification to detect FB1. Bi2S3/BiOCl has a wide range of visible light absorption, stable chemical properties, and asimple synthesis method. In the construction process, L-ascorbic acid (AA) is selected to provide electrons and inhibit photogenerated electron-hole (e-/h+) recombination. Under the optimal experimental conditions, the detection range of the fabricated PEC aptasensor was 0.001 ~ 100ng/mL, and the detection limit was 0.016pg/mL. The prepared PEC aptasensor has high sensitivity, stability, and reproducibility. The combination of aptamer and PEC sensor provides a novel method for the application of PEC sensor in mycotoxin detection.

Carbothermal Shock Derived Electrochemical Regeneration of Spent Biochar for Remediation of Ciprofloxacine Contaminated Water

Biochar, derived from waste biomass, is a potent material for carbon dioxide sequestration, owing to its stable, non-degradable aromatic structure [1]. Biochar is found to have advantageous characteristics, such as a unique pore structure, large specific surface area, complex surface-active functional groups, and stable chemical properties. These properties make biochar as a high potential biosorbent for removal of pollutants from water [2]. Meanwhile, the escalating use of pharmaceuticals has led to pervasive environmental residues, posing public health risks. Specifically, antibiotic contamination risks augmenting antibiotic resistance, underscoring the need for efficient wastewater treatment methods [3]. However, current wastewater treatment plant(WWTP) based on biological treatment was not effectively eliminate this types of waste in the water and it is necessary to investigate efficient method for removal of antibiotics from wastewater.This study explores the use of biochar for ciprofloxacin (CIP) removal from water and introduces a novel electrochemical biochar regeneration technique. We utilized sludge from chemical plants to produce biochar through standard and alkali-activated pyrolysis, yielding CB (normal pyrolysis) and CAB (alkali activated pyrolysis) types with distinct physicochemical properties. CAB, with an exceptionally high surface area (~2330 m²/g) and carbon purity (95.4%), demonstrated superior CIP adsorption capacity (~550 mg/g). We investigated the CIP adsorption isotherm, kinetics and thermodynamics to elucidate the underlying mechanisms, which appear dominated by π-π and electrostatic interactions facilitated by the high pyrolysis temperatures reducing oxygen-containing groups on the biochar. After the biochar became saturated with CIP, we regenerated it using joule heating in Ar atmosphere, employing the carbothermal shock method for rapid, short-duration temperature increases [4]. In contrast to traditional CTS which can sometimes lead to structural damage by directly heating the material on the carbon substrate [5], we used radiant heat from the CTS process to ensure controlled temperature elevation. This modified approach maintains the structural integrity of the biochar by avoiding direct contact between the biochar and the carbon substrate while facilitating the regeneration process. Additionally, this method facilitates the physical separation of the biochar from the carbon substrate, enhancing the recovery and reuse of biochar. Such an approach contributes to the efficient regeneration of biochar and environmentally friendly processing. We examined parameters such as distance from the substrate and duration to optimize the regeneration conditions. Ultimately, we assessed the efficacy of the CIP adsorption by the regenerated biochar. Traditional thermal treatments for biochar regeneration are energy-intensive and time-consuming. We propose an innovative approach using joule heating under a nitrogen atmosphere, employing carbothermal shock for rapid, efficient regeneration. By optimizing parameters such as voltage and duration, we identified ideal conditions for regenerating biochar, significantly enhancing its CIP adsorption efficacy. This study not only highlights the potential of biochar in environmental remediation but also introduces an energy-efficient regeneration method, contributing to sustainable pollution management solutions.

(Invited) Titanium Dioxide Photocatalyst Treated by in-Liquid Plasma and Its Application in Environmental Purification

Titanium dioxide (TiO2) has been widely investigated as photocatalyst because of its environmentally and economically advantages with high chemical stability, earth abundant and biocompatible properties. However, its large band gap for the activity to only UV light region, and the high recombination rate of photogenerated electron and hole pairs have to be overcome to utilize effectively sunlight, and to enhance the photocatalytic performance. Recent enormous efforts to overcome the above-mentioned drawbacks have resulted in the one-dimensional TiO2 nanotubes, nanofibers and nanorods to suppress the carrier recombination, and/or the heterojunction structure of TiO2 with another semiconductor to achieve larger separation of the photogenerated electron and hole, as well as the modification of TiO2 nanoparticles with gold clusters to expand the light conversion from UV to visible and near-infrared region. Another interesting approach on black TiO2 nanoparticles succeeded in narrowing the band gap of pure white TiO2 nanoparticles, however, it required the hard treatment condition of a 2 MPa hydrogen atmosphere at ca. 200 °C for 5 days (X. Chen, et al., Science, 331 (2011) 746). In order to synthesize the hydrogenated TiO2 nanoparticles, the thermal treatment under hydrogen and plasma treatment have mostly relied on the reduction of TiO2 nanoparticles. But, these processes have drawbacks such as high temperature over 1,000 °C, vacuum system for hydrogen plasma and long treatment time. After thermal treatment, the sintered nanoparticles should be crush to follow multistep processes. Thus, alternative approaches have been highly demanded in the reduction of TiO2 with keeping its nano-sized particle.On the other hand, non-equilibrium plasma, in which the electron temperature is very high and deviates from the ion temperature, is an attractive reaction field because it can achieve low temperature processes in material synthesis and other applications. In particular, when plasma is generated in a liquid, reaction processes below the boiling point of the liquid become possible, and a special reaction field can be expected to be formed. In a so-called solution plasma using a bipolar pulse power supply (O. Takai, Pure Appl. Chem., 80 (2008) 2003), the solvent was water, and plasma was generated in an air-fed environment within solvent. Therefore, the surface modification of TiO2 nanoparticles in a solution plasma reaction field to introduce oxygen vacancy on the sub-surface while maintaining the nano-size has succeeded in improving photocatalytic activity (S. Pitchaimuthu, C. Terashima et al., ACS Omega 3 (2018) 898). The present study focused to treat pristine TiO2 nanoparticles by the discharge in water-based solution and to investigate the material properties as well as the photocatalytic activities for decomposing organics.