Recycling Tests Research Articles

Nitrogen-vacancy-rich molybdenum nitride nanosheets as highly efficient electrocatalysts for nitrogen reduction reaction.

The development of low-cost earth-abundant electrocatalysts to produce ammonia (NH3) with high efficiency for the nitrogen (N2) reduction reaction (NRR) remains challenging. Herein, we propose the development of highly efficient ultrathin nitrogen-vacancy-rich molybdenum nitride nanosheets (MoN-NV) for NRR using basic electrolytes under ambient conditions. In 0.1 M KOH, this catalyst attained a high faradaic efficiency (FE) of ∼14% with an NH3 yield of 22.5 μg h-1 mg-1cat at -0.3 V vs. a reversible hydrogen electrode under ambient conditions. The characterization results and electrochemical studies disclosed that nitrogen vacancies in the MoN-NV nanosheets played a critical role in the enhanced electrocatalytic activity for NRR. Furthermore, the recycling tests confirmed the stability of the catalyst during NRR electrolysis.

Hydrothermal synthesis of Mg/Al-layered double hydroxide modified water hyacinth hydrochar for remediation of wastewater containing mordant brown dye.

A high-performance dye adsorbent of Mg/Al-layered double hydroxide modified water hyacinth hydrochar (MgAl@WH) was synthesized by a simple hydrothermal method. The surface functional groups, elemental composition, crystalline structure, and surface morphology of the prepared (MgAl@WH) were determined using different analytical techniques. The characterization results revealed that the (MgAl@WH) hydrochar surface offered more active adsorption sites, facilitating the mordant brown (anionic dye) adsorption, leading to its superior performance with much higher uptake capability (311.0 mg g-1 at 298 K) than Mg/Al double hydroxide nanosheets (MgAl DLHs, 80.2 mg g-1 at 298 K) and dried water hyacinth (WH, 10.0 mg g-1 at 298 K). The adsorption behavior of MgAL@WH follows the pseudo second order kinetic model (R2 = 0.999) and Langmuir isotherm model (R2 = 0.999). Moreover, MgAl@WH bonded efficiently with mordant brown dye via hydrogen bonding and interlayer anion exchange with monolayer formation. Additionally, the recycling tests revealed that the MgAl@WH can be reused over 10 cycles without significant change in the removal efficiency. Based on the obtained findings, Mg/Al-layered double hydroxide modified water hyacinth hydrochar (MgAl@WH), for its economic and environmental benefits, has recently been used as an efficient adsorbent to remediate industrial wastewater containing anionic dyes.

A floating photocatalytic fabric integrated with a AgI/UiO-66-NH2 heterojunction as a facile strategy for wastewater treatment.

With an increased need of wastewater treatment, application of photocatalysts has drawn growing research attention as an advanced water remediation strategy. Herein, a floating photocatalytic fabric in a woven construction was developed for removal of Rhodamine B (RhB) in water. For an efficient photocatalytic reaction, AgI nanoparticles were grown on the surface of UiO-66-NH2 crystals in a layered structure, forming a heterojunction system on a cotton yarn, and this was woven with polypropylene yarn. The floating photocatalyst demonstrated the maximized light utilization and adequate contact with contaminated water. Through the heterojunction system, the electrons and holes were effectively separated to generate reactive chemical species, and this eventually led to an enhanced photocatalytic performance of AgI/UiO@fabric reaching 98% removal efficiency after 2 hours of irradiation. Photodegradation of RhB occurred mainly by superoxide radicals and holes, which were responsible for de-ethylation and decomposition of an aromatic ring, respectively. The kinetics of the photocatalytic reaction suggested that circulation of solution by stirring affected the photocatalytic removal rate. The recycle test demonstrated the potential long-term applicability of the developed material with structural integrity and catalytic stability. This study highlights the proof-of-concept of a floating photocatalytic material for facile and effective water remediation with repeated usability.

Isotype heterojunction: tuning the heptazine/triazine phase of crystalline nitrogen-rich C3N5 towards multifunctional photocatalytic applications.

Photocatalytic technology has been well studied as a means to achieve sustainable energy generation through water splitting or chemical synthesis. Recently, a low C/N atomic ratio carbon nitride allotrope, C3N5, has been found to be highly prospective due to its excellent electronic properties and ample N-active sites compared to g-C3N4. Tangentially, crystalline g-C3N4 has also been a prospective candidate due to its improved electron transport and extended π-conjugated system. For the first time, our group successfully employed a one-step molten salt calcination method to prepare novel N-rich crystalline C3N5 and elucidate the effect of calcination temperature on the heptazine/triazine phase. Calcination temperatures of 500 °C (CC3N5-500) and 550 °C (CC3N5-550) lead to crystalline carbon nitride with both heptazine and triazine phases, forming an intimate isotype heterojunction for robust interfacial charge separation. An excellent photocatalytic hydrogen evolution rate (359.97 μmol h-1; apparent quantum efficiency (AQE): 12.86% at 420 nm) was achieved using CC3N5-500, which was 15-fold higher than that of pristine C3N5. Furthermore, CC3N5-500 exhibited improved activity for simultaneous benzyl alcohol oxidation and hydrogen production, as well as H2O2 production (AQE: 9.49% at 420 nm), signifying its multitudinous photoredox capabilities. Moreover, the recyclability tests of the optimal CC3N5-500 on a 3D-printed substrate also showed a 92% performance retention after 4 cycles (16 h). This highlights that crystalline C3N5 significantly augmented the reaction performance for diverse multifunctional solar-driven applications. As such, these results serve as a guide toward the structural tuning of 2D metal-free carbon nanomaterials with tunable crystallinity toward achieving boosted photocatalysis.

Extraction and Purification of Aucubin from Eucommia ulmoides Seed Draff in Natural Deep Eutectic Solvents Using Macroporous Resins.

Aucubin (AU) is an active ingredient that exerts strong antioxidant and anti-inflammatory effects in the treatment of several diseases. In order to improve the efficiency of resource utilization of traditional biomass waste, Eucommia ulmoides seed-draff (EUSD) waste biomass was used as the raw material, and a series of deep eutectic solvents were selected to evaluate the extraction efficiency of aucubin from EUSD. A response surface experiment was designed based on a single-factor experiment to optimize the extract conditions. The results showed that the best conditions for aucubin extraction were an HBD-HBA ratio of 2.18, a liquid-solid ratio of 46.92 mL/g, a water percentage of 37.95%, a temperature of 321.03 K, and an extraction time of 59.55 min. The maximum amount of aucubin was 156.4 mg/g, which was consistent with the theoretical value (156.8 mg/g). Then, the performance of 12 resins for adsorption and desorption was contrasted. The results revealed that HPD950 resin exhibited the best performance, with an adsorption capacity of 95.2% and a desorption capacity of 94.3%. Additionally, the pseudo-second-order model provided the best match to the kinetics data, the Langmuir model provided the best fit to the isotherm data, and adsorption was a beneficial, spontaneous, exothermic, and physical process. In the recyclability test, the HPD950 resin had great potential and excellent sustainability in aucubin recovery. In the antioxidant activity study, the aucubin extract exerted a strong antioxidant ability with scavenging capabilities for four free radicals. Furthermore, the antifungal activity study found that the aucubin extract exhibited a good antifungal effect against 5 tested pathogens. The research results can provide a theoretical basis for the extraction of high-value components from waste biomass by deep eutectic solvent and a certain application value for the development and utilization of natural aucubin products.

2D/3D MXene/NiFeMn-layered double hydroxide decorated gelatin for removal of Cr(VI) and Congo red: Performance and mechanism

The discharge of toxic heavy metals and dyes into water is considered a principal reason for ecosystem deterioration. Therefore, the development of versatile adsorbents that can treat this threat is an urgent issue. On this basis, we designed and characterized a novel Ti3C2TX/NiFeMn-LDH@Gel composite to aptly remove hazardous hexavalent chromium ions Cr(VI) and organic Congo red dye (CR). Ti3C2TX/NiFeMn-LDH@Gel composite was facilely synthesized by introducing NiFeMn-layered double hydroxide and Ti3C2TX MXene into gelatin via a cross-linking reaction. Experimental data revealed that raising Ti3C2TX amount to 10 % in the matrix has dramatically promoted the adsorption aptitude of Ti3C2TX/NiFeMn-LDH@Gel towards Cr(VI) and CR. Freundlich model best described Cr(VI) and CR adsorption, with qmax reaching 423.73 mg/g, and 588.24 mg/g, respectively. Additionally, the adsorption kinetics of Cr(VI) and CR were fitted to the pseudo-second order model accompanied with spontaneity, randomness, and endothermic behavior. In addition, stability, and selectivity of Ti3C2TX/NiFeMn-LDH@Gel were investigated. Effect of ionic strength and interfering ions were explored as well. Besides, the recyclability test inferred superb adsorption capacities towards Cr(VI) and CR till the 5th cycle, revealing the potentiality of Ti3C2TX/NiFeMn-LDH@Gel towards anionic contaminants removal.

Use of iron-bearing waste materials in laundry wastewater treatment

This study evaluates the efficiency of a steel waste-derived magnetite (WM) for the treatment of laundry wastewater under various irradiation conditions (ultraviolet-A and C: UVA and UVC), both in the presence and absence of H2O2. Because WM can contain magnetite and elemental iron phases, its ability to remove ciprofloxacin and phenol, here used as model pollutants, and total organic carbon (TOC) from laundry wastewater was compared with that of synthetic magnetite (SM) and zero-valent iron (ZVI). We show that the mixed ZVI/H2O2 system under UVC degraded up to 80 % of the pollutant and 70 % of the TOC. WM had, on the other hand, a lower reactivity for pollutants due to the presence of inorganic impurities, yet removed up to 60 % of TOC. In all cases considered in this work, a higher degradation rate was observed under UVC irradiation than under UVA. Moreover, iron-based materials can adsorb heavy metals co-existing in the laundry wastewater. Recyclability tests showed no significant loss in the activity of WM or SM for up to 5 cycles in laundry wastewater. This study can have strong implications for the development of new remediation technologies relying on industrial solid wastes, especially in the context of a circular economy.

Enhanced Redox Cycle of Rod-Shaped MIL-88A/SnFe2O4@MXene Sheets for Fenton-like Degradation of Congo Red: Optimization and Mechanism.

This study intended to fabricate a novel Fenton-like catalyst by supporting the rod-like MIL-88A and the magnetic tin ferrite nanoparticles (SnFe2O4) on the MXene sheets (MIL-88A/SnFe2O4@MXene). The well fabrication and determination of the MIL-88A/SnFe2O4@MXene properties were investigated using SEM, XPS, VSM, Zeta potential, XRD, and FTIR tools. The Fenton-like degradation reaction of CR by MIL-88A/SnFe2O4@MXene was thoroughly studied to identify the optimal proportions of the catalyst components, the impact of CR and H2O2 concentrations, as well as the effect of raising the temperature and the pH medium of the catalytic system and the catalyst dosage. Kinetics studies were executed to analyze the decomposition of CR and H2O2 using First-order and Second-order models. Furthermore, the degradation mechanism was proposed based on the scavenging test that proceeded in the presence of chloroform and t-butanol, in addition to the XPS analysis that clarified the participation of the containing metal species: Fe, Sn, and Ti, and the formation of a continual redox cycle. The obtained intermediates during the CR degradation were defined by GC-MS. A recyclability test was performed on MIL-88A/SnFe2O4@MXene during five runs of the Fenton-like degradation of CR molecules. Finally, the novel MIL-88A/SnFe2O4@MXene Fenton-like catalyst could be recommended as a propitious heterogeneous catalyst with a continuous redox cycle and a recyclability merit.

Synthesis and characterization of a novel MnO2@MXene-based 2D/3D hierarchical Z-scheme for sustainable environmental applications

A wet chemical synthesis of a novel 2D/3D hierarchical Z-scheme that utilizes manganese oxide decorated 2D Ti3C2 MXene (MnO2@MXene), which is designed for effective utilization in environmentally sustainable applications, is presented in this study. The synergistic role of 20 nm thick MnO2 nanopetals (NPTs) and MXene sheets, which inhibited the electron/hole pair recombination and improved the surface activity, enhanced the catalytic properties of the material. This was facilitated by the unique 3D/2D structural characteristics of MnO2 NPTs and MXene. The MnO2 nanopetals NPTs integrated the MXene-based photocatalyst, which was synthesized using the ultrasonication approach, removed ∼99 % of the methylene blue dye (MB) and 75 % of the phenol within 30 min. The antibacterial test of the as-prepared MnO2@MXene simultaneously confirmed its admirable antibacterial efficacy. The recyclability test verified that the synthesized material can be recycled multiple times without a significant loss, which was only a 3 % loss in this case, in photocatalytic activity. The results imply that MnO2@MXene has significant promise as an eco-friendly material that is suitable for utilization in photocatalytic and antibacterial applications.

Preparation of Co–CaCO3 catalysts for improved hydrogen production from sodium borohydride

Ca1-xCoxCO3 nanoparticle catalysts (x = 0.0, 0.1, 0.2 and 0.3 %) were prepared by the sol-gel method. The samples were characterized using various techniques such as X-ray diffraction (XRD), attenuated total reflectance spectroscopy (ATR), environmental scanning electron microscopy (ESEM), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) surface area analysis. The XRD peaks of Ca1-xCoxCO3 displayed a significant level of conformity with the rhombohedral calcite structure. The average crystal size of Ca1-xCoxCO3 nanoparticles was found to be 14 nm. The ESEM micrographs of Ca1-xCoxCO3 showed rhombic calcite shapes. The most prominent peaks in the XPS spectra of Ca1-xCoxCO3 are the Ca 2p, C 1s, Co 2p and O 1s peaks. The sample Ca1-xCoxCO3 has the highest surface area (58.27 m2/g) and large pore size (20.25 Å). The rates of hydrogen production for CaCO3, Ca0.9Co0.1CO3, Ca0.8Co0.2CO3 and Ca0.7Co0.3CO3 were 5204, 4381, 6666 and 6136 mL/g.min. The Ca0.8Co0.2CO3 catalyst revealed an activation energy for hydrogen catalytic reaction of 34.56 kJ/mol. The recyclability tests of Ca1-xCoxCO3 catalysts showed a reduction of efficiency by 7 % over 5 reaction cycles. Accordingly, the prepared Ca1-xCoxCO3 catalysts are promising for improved hydrogen production systems. This research contributes to advancements in hydrogen production technology.

3D integrated non-noble metal oxides nano arrays for enhanced nitrate electroreduction to ammonia

The electrochemical nitrate reduction reaction (eNO3RR) to ammonia (NH3) is a promising alternative method to the Haber-Bosch process that requires high temperature and pressure. In this contribution, the integrated Co3O4 nanowire arrays on Ni foam (Co3O4/NF) are reported to exhibit the outstanding performance with a high NH3 yield rate of 117.01 mg h−1cm−2, a superior NH3 Faradaic efficiency of 99.28 %, a high effective current density of 1475.71 mA cm−2, and a good operation durability during 40 consecutive recycling tests (40 h) in 1.0 M NaOH (0.1 M NaNO3). The high-valence metal cations as electron-deficient centers can act as Lewis-acid sites, favorably interacting with the Lewis base NO3−, and accordingly boosting the NO3− adsorption and activation. Moreover, the in-situ growth array configuration provides the substantial active sites and constructs a fast electron-transport channel, thus facilitating the conversion of NO3−-to-NH3. Density functional theory (DFT) calculations also reveal that the Co atoms as the active sites are preferred to adsorb NO3−, implying that the NO3− electroreduction dominates the cathodic reaction rather than hydrogen evolution reaction. This study provides a viable method to design integrated electrodes with enhanced eNO3RR activity and selectivity, which might have broad prospects in the application of renewable energy.

Sweety, salty, sour, and romantic biochar-supported ZnO: highly active composite catalysts for environmental remediation

AbstractThe present work focuses on valorizing the various biochar supports of nano-catalysts and investigates the effect of the type of the initial biomass on the deposition and salient physico-chemical features of the zinc oxide (ZnO) nanoparticles. In this regard, we have used four different biomasses, namely, sugarcane bagasse (Saccharum officinarum), algae (Phaeophyta), mandarin orange peels (Citrus reticulata), and China rose petals (Rosa chinensis) as sources of biochar. Their wet impregnation with zinc acetate was followed by pyrolysis at 500 °C. It led to biochar (nicknamed “sweety,” “salty,” “sour,” and “romantic” biochar, respectively) loaded with very well dispersed, 20–360 nm-sized (mostly) ZnO nanoparticles. Interestingly, depending on the type of biomass used, the size, shape (quartz-like, semi-spherical, spherical, semi-cauliflower, needle or rod-like), and degree of crystallinity of ZnO nanoparticles (hexagonal crystal system) vary, in spite of all other synthesis parameters being similar. Nanoparticle-induced graphitization and crystallization of biochar have been also observed by Raman spectroscopy. The malachite green dye mineralization efficiency in the presence of H2O2 and different biochar-supported ZnO nanocatalysts was 15.1%, 46.3%, 99.9%, 67.9%, and 66.4% for H2O2, china rose petals, algae, mandarin peels, and sugarcane bagasse-supported ZnO catalyst in the presence of H2O2, respectively. Malachite green removal fits in very well with a pseudo-first-order kinetic model with R2 = 0.9701 (at algae biochar-ZnO). 6.6 times enhancement in the mineralization efficiency is observed as compared to just H2O2. The recyclability test of algae biochar impregnated with ZnO after 5 cycles indicates the mineralization efficiency levels up to 81.4%. Beyond these scientific results, this work is based on the principle of biomass waste valorization for sustainable development and circular economy, on the one hand, and addresses the UN Sustainable Development Goals 6, 13, and 14, on the other hand. It is also very clear that biochar is the new romance in the field of materials science and for sustainable future. Graphical Abstract

Influence of cerium and iron substitution on the Bi2WO6 hierarchical microsphere and their enhanced photocatalytic degradation performance

A facile hydrothermal approach was employed to synthesize cerium and iron co-doped Bi2WO6 photocatalysts, and their photocatalytic performance for the degradation of cationic rhodamine B (RhB) and thionine (TH) dyes under UV–visible light illumination was investigated. Powder XRD investigation revealed that the Ce and Fe ions significantly influenced the Bi2WO6 crystal structure, while HR-XPS confirmed the valence states of Ce and Fe ions in the Bi2WO6 lattice. The light absorption wavelength of the co-doped samples was red-shifted when compared to the pristine Bi2WO6. The photoluminescence spectroscopy results showed that the synergistic effect of the Ce–Fe intermediate state in the Ce–Fe co-doped Bi2WO6 photocatalyst significantly reduced the recombination of photoinduced electron-hole pairs and boosted photocatalytic degradation activity. Furthermore, the stability of the best-performed catalyst was verified using recycling tests. The degrading efficiency of TH and RhB was not significantly affected after five repeated cycles. A potential mechanism for increased photocatalytic activity was also discussed.

An efficient wastewater treatment through reduction of organic dyes using Ag nanoparticles supported on cellulose gum beads

This work reports silver nanoparticles (AgNPs) supported on biopolymer carboxymethyl cellulose beads (Ag-CMC) serves as an efficient catalyst in the reduction process of p-nitrophenol (p-NP) and methyl orange (MO). For Ag-CMC synthesis, first CMC beads were prepared by crosslinking the CMC solution in aluminium nitrate solution and then the CMC beads were introduced into AgNO3 solution to adsorb Ag ions. Field emission scanning electron microscopy (FE-SEM) analysis suggests the uniform distribution of Ag nanoparticles on the CMC beads. The X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis revealed the metallic and fcc planes of AgNPs, respectively, in the Ag-CMC catalyst. The Ag-CMC catalyst exhibits remarkable reduction activity for the p-NP and MO dyes with the highest rate constant (kapp) of a chemical reaction is 0.519 and 0.697 min−1, respectively. Comparative reduction studies of Ag-CMC with CMC, Fe-CMC and Co-CMC disclosed that Ag-CMC containing AgNPs is an important factore in reducing the organic pollutants like p-NP and MO dyes. During the recyclability tests, the Ag-CMC also maintained high reduction activity, which suggests that CMC protects the AgNPs from leaching during dye reduction reactions.

Synthesis and application of recyclable magnetic cellulose nanocrystals for effective demulsification of water in crude oil emulsions

The development of eco-friendly, efficient, and economical demulsifiers for the demulsification of water in crude oil emulsion is one of the important issues in the petroleum industry. Demulsifiers with suitable performance in several demulsification methods are good choices for effective and economical demulsification. In this study, recyclable magnetic cellulose nanocrystals have been synthesized from cotton by a simple method and used in the demulsification of water in crude oil emulsions. Chemical and magnetic demulsification by magnetic cellulose nanocrystals has been investigated. In addition, the effects of time, temperature, and demulsifier concentration on the demulsification efficiency have been evaluated. According to the results, this demulsifier can be used as an effective demulsifier for both chemical and magnetic demulsification and displayed a demulsification efficiency of 100 % at 50 °C without a magnet and 90 % at 20 °C with a magnet. The chemical demulsification efficiency of Fe3O4 nanoparticles was investigated and it showed lower DE compared to magnetic cellulose nanocrystals. The recyclability tests of the demulsifier indicated that magnetic cellulose nanocrystals can be used up to 4 times. Finally, the demulsification mechanism and interfacial tension measurements revealed that this demulsifier reduced the interfacial tension between water and crude oil and increased the water droplet sizes.

Simultaneous enhanced generation of reactive oxygen species and H2 over Pd-(Cu-s-Fe0) trimetal for bifunctional catalytic degradation of refractory combined pollutants

Presently, it is a great challenge to maintain high catalytic reactivity and recycling performance of zero-valent iron (ZVI) for rapid degradation of refractory combined pollutants possessing electron withdrawing groups and electron-donating groups, simultaneously. The state-of-the-art ZVI technique aims to enhance the generation of reactive oxygen species (ROSs) and H2 with the construction of novel noble metals-decorated ZVI-based tri(bi)metal. Herein, we selected the precursors of Cu(NO3)2 and KPdCl6 to synthesize sponge iron (s-Fe0)-based trimetal via interfacial displacement reactions and further disclosed the main influencing factors for detailed evaluation of ideal trimetal. The results show that the preferred palladised copper-decorated s-Fe0 (0.025 wt%Pd-(5 wt%Cu-s-Fe0)) with 30 g/L input dosage could achieve ∼ 90% removal of 20 mg/L rhodamine B (RhB) within four recycling tests. The aeration process over trimetal (Pd-(Cu-s-Fe0)/O2) as well as the addition of H2O2 (Pd-(Cu-s-Fe0)/H2O2) further achieves high catalytic reactivity and recycling performance. Moreover, Pd-(Cu-s-Fe0) could effectively degrade a series of combined pollutants including RhB + triclosan and RhB + tetrabromobisphenol A (TBBPA), respectively. Furthermore, the interfacial nanostructures of Pd–Cu covering the surface of trimetal have been characterized and the variations of ROS have been recorded with electron spin resonance (ESR) signals. Additionally, the bicatalytic mechanism over Pd-(Cu-s-Fe0) has been explored. Accordingly, the simultaneous generation of ROSs and H2 over Pd-(Cu-s-Fe0) highlights the significant potential for rapid degradation of a series of refractory combined pollutants.

Heterogeneous Integration Supply Chain Integrity Through Blockchain and CHSM

Over the past few decades, electronics have become commonplace in government, commercial, and social domains. These devices have developed rapidly, as seen in the prevalent use of system-on-chips rather than separate integrated circuits on a single circuit board. As the semiconductor community begins conversations over the end of Moore’s law, an approach to further increase both functionality per area and yield using segregated functionality dies on a common interposer die, labeled a System in Package (SiP), is gaining attention. Thus, the chiplet and SiP space has grown to meet this demand, creating a new packaging paradigm, advanced packaging, and a new supply chain. This new distributed supply chain with multiple chiplet developers and foundries has augmented counterfeit vulnerabilities. Chiplets are currently available on an open market, and their origin and authenticity consequently are difficult to ascertain. With this lack of control over the stages of the supply chain, counterfeit threats manifest at the chiplet, interposer, and SiP levels. In this article, we identify counterfeit threats in the SiP domain, and we propose a mitigating framework utilizing blockchain for the effective traceability of SiPs to establish provenance. Our framework utilizes the Chiplet Hardware Security Module to authenticate a SiP throughout its life. To accomplish this, we leverage SiP information including electronic chip identification of chiplets, combating die and IC recycling sensor information, documentation, test patterns and/or electrical measurements, grade, and part number of the SiP. We detail the structure of the blockchain and establish protocols for both enrolling trusted information into the blockchain network and authenticating the SiP. Our framework mitigates SiP counterfeit threats including recycled, remarked, cloned, overproduced interposer, forged documentation, and substituted chiplet while detecting of out-of-spec and defective SiPs.

Catalytic activation of peracetic acid for pelargonic acid vanillylamide degradation by Co3O4 nanoparticles in-situ anchored carbon-coated MXene nanosheets: Performance and mechanism insight

Pelargonic acid vanillylamide (PAVA), a capsaicin-type dacryagogue agent utilized for counter-terrorism and riot control, possesses a low stimulus threshold. This characteristic can lead to environmental contamination following its application and may easily result in secondary stimulation to personnel. Cobalt-doped Ti3C2-MXene nanosheets (Co3O4/Ti3C2@C) were synthesized for the purpose of activating peracetic acid (PAA) and degrading PAVA. A carbon layer was coated on the surface of Ti3C2-MXene nanosheets to address the challenge of poor oxygen resistance in MXenes, thus preventing a significant decline in surface reactivity. The BET surface area of Co3O4/Ti3C2@C was expanded to 149.6 m2/g, significantly exceeding that of Ti3C2 (13.0 m2/g) and Co3O4 (56.4 m2/g). With 0.5 mg/mL of Co3O4/Ti3C2@C and 0.35 mM of PAA, 100 mg/L of PAVA was completely degraded within 60 min. The augmented BET surface area and the presence of more active sites confer remarkable PAA activation and catalytic degradation properties toward PAVA. Parameters such as initial pH, PAVA concentration, catalyst dosage, and PAA concentration on PAVA degradation were systematically assessed. Furthermore, the reusability and stability of the nanocomposite were substantiated through recycling tests. Radical quenching experiments and electron paramagnetic resonance analysis demonstrated the acetylperoxy radical (CH3CO3) as the primary species responsible for PAVA degradation. This research serves as an illustration of the utilization of MXene and transition metal activated PAA in wastewater treatment.

Efficient Iodine Uptake of Ultra Thermally Stable Conjugated Copolymers Bearing Biaceanthrylenyl Moieties and Contorted Aromatic Units Using a [3 + 2] Palladium-Catalyzed Cyclopolymerization Reaction.

A novel series of copolymers made from alternating aromatic surrogates with contorted and spiro compounds, denoted as BCP1-3, was successfully synthesized employing a palladium-catalyzed one-pot [3 + 2] cyclopentannulation reaction. The resulting copolymers BCP1-3, which were isolated in high yields, exhibited weight-average molecular weights (Mw) ranging from 11.0 to 61.5 kg mol-1 (kDa) and polydispersity index (Mw/Mn) values in the range of 1.7 and 2.0, which suggest a narrow molecular weight distribution, thus indicating the formation of uniform copolymer chains. Investigation of the thermal properties of BCP1-3 by thermogravimetric analysis disclosed outstanding stability with 10% weight loss temperature values reaching 800 °C. Iodine adsorption tests revealed remarkable results, particularly for BCP2, which demonstrated a strong affinity toward iodine reaching an uptake of 2900 mg g-1. Additionally, recyclability tests showcased the effective regeneration of BCP2 after several successive iodine adsorption-desorption cycles.

Role of the surface chemistry of carbon xerogel-based supports and Cu catalysts in the oxidation reaction of glycerol

Carbon xerogel with pore size of about 10 nm were obtained using the sol–gel method and applying different thermal treatments. Catalysts were prepared depositing 3 wt% of copper on the xerogel. The catalytic activities of catalysts and supports were evaluated in the selective oxidation of glycerol (GLY). The supports showed good conversion and selectivity to glyceric acid (GA) and lactic acid (LA), with higher preference to GA. For the catalysts, the conversions were slightly higher, and the order of selectivity changed, benefiting the production of LA. Changes in selectivity between supports and catalysts were mainly associated with the different acid-base surface characteristics and the presence of the Cu domains in the catalysts. In the supports, even if the thermal treatment applied modifies the type and content of oxygenated functional groups (OFG) on the surface, predominates a superficial acid character, addressing the selectivity to GA. On the other hand, the basic character of the catalysts due to the Cu presence and the large metallic domain sizes favoured the production of LA. During the recycle test, supports and catalysts showed a decrease in catalytic activity. After three recycles, the catalytic performances of catalysts and supports were similar due to metal leaching.