Iron-chromium redox flow batteries (ICRFBs) have emerged as a promising candidate for large-scale energy storage due to their cost-effectiveness, long cycle life, power-energy decoupling, and inherent safety. However, conventional ICRFBs using acidic FeCl₂ + CrCl₃ + HCl electrolytes face critical challenges, including severe material corrosion, active species cross-contamination, and parasitic hydrogen evolution reactions. To address these issues, we propose a neutral chelated Fe/Cr electrolyte system utilizing the identical ligand, 1,3-diaminopropanetetraacetic acid (DTPA), for both half-cells. This symmetric ligand design effectively suppresses metal ion crossover while enhancing redox kinetics, as confirmed by Fourier transform infrared (FTIR) and ultraviolet–visible (UV–vis) spectroscopy. The DTPA-complexed electrolytes exhibit high solubility (up to 1.0 mol/L) and environmental benignity, eliminating the need for corrosive acids. The resulting ICRFB demonstrates outstanding performance: a discharge energy density of 12.1 Wh/L, an average capacity decay rate of 0.13

In the original publication [...].

By combining the sulfate radical (SO4 center dot-), hydroxyl radical (center dot OH), and singlet oxygen (1O2), the elimination efficiency of refractory organic contaminants through activating peroxymonosulfate (PMS) would improve owing to the highly selective oxidation of 1O2 towards electrophilic pollutants. CuO catalyst possesses good performance for activating PMS, but the dispersion of nano-particles and the introduction of defects (such as oxygen vacancies, OV) in CuO are still the challenges. In this study, ZnO-modified CuOx@C (denoted ZnCuOx@C) was obtained by pyrolyzing Zn(NO3)2 doped HKUST-1(Cu) in N2. The as-synthesized ZnCuOx@C showed dispersed active sites and rich OV compared to undoped CuOx@C. The amount of OV in ZnCuOx@C could be prominently enhanced through the introduction of Zn, resulting in the evolution of 1O2 during the PMS activation by ZnCuOx@C. The optimal ZnCuOx@C could realize complete degradation of bisphenol A (BPA, 60 mg/L) in 30 min and the reactive rate constant (k) was 0.15 min-1, which significantly outperformed that CuOx@C (0.0076 min-1) derived from undoped HKUST-1(Cu). SO4 center dot-, center dot OH, and 1O2 as reactive oxygen species (ROSs) involved in the oxidation of BPA, and 1O2 was the dominant ROSs generated in the ZnCuOx@C/PMS system. The mechanism of the ZnCuOx@C/PMS system was further discussed. This study not only gave a new strategy for rational design and regulation of defects in MOFs-derived catalysts by the interaction between guest and host, but also opened a new insight into the PMS activation mechanism through the nonradical dominant pathway by ZnCuOx@C with rich OV derived MOFs for high-efficiency water purification.

A series of novel protonated amination magnetic chitosan microspheres (P-A-MCMs) were successfully prepared for efficient iodide (I-) removal from nuclear wastewater through the amination and protonation modifications using as-synthesized core-shell-shaped magnetic chitosan microspheres (MCMs) as the matrix materials. The morphology, composition, and surface property of microspheres were fully characterized by various analytical techniques. The characterization results confirmed the successful introduction of protonated amine groups while retaining the good magnetic properties of microspheres. The I- adsorption mechanism of P-A-MCMs was primarily governed by electrostatic attraction and ion-exchange process. Among the prepared P-A-MCMs, the protonated tetraethylenepentamine magnetic chitosan microspheres (P-TEPA-MCMs) achieved over 89 % iodide removal efficiency across a wide pH range of 3 to 11. The maximum I- adsorption capacity of P-TEPA-MCMs reached 1.3482 mmol g-1 within 120 min at 298 K, which was 1.67-fold greater than unmodified MCMs. Thermodynamic and kinetic analyses revealed that the I- adsorption process of P-A-MCMs was dominated by the monolayer physisorption, following the pseudo-first-order, Langmuir and Dubinin-Radushkevish models. Notably, the P-A-MCMs maintained a high I- removal efficiency of 88.4 % after ten regeneration cycles, demonstrating excellent reusability. These findings highlight the potential of P-A-MCMs as a cost-effective, high-performance, and recyclable adsorbent for managing radioactive iodide in nuclear wastewater.

Fenton-like technology can efficiently dispose of recalcitrant pollutants, but developing catalytic oxidation system for deep mineralization of pollutants remains a challenge. Therefore, spinel Cu1.5Mn1.5O4 nanospheres anchored N-doped carbon (Cu1.5Mn1.5O4@N-C) was prepared by a one-step calcination method and used to activate peroxymonosulfate (PMS) for efficient mineralization in bisphenol A (BPA) removal. The results showed the use of 0.5 g L-1 Cu1.5Mn1.5O4@N-C and 0.2 g L-1 PMS made 50 mg L-1 BPA being completely degraded and deeply mineralized (nearly 100%) in 9 min. The corresponding rate constant k was 0.557 min-1, which was 61.9, 6.2 and 2.5 times than those of N-C/PMS (0.009 min-1), CuO@N-C/PMS (0.09 min-1) and Mn3O4@N-C/PMS (0.22 min-1). The effect of the molar ratio of Cu and Mn precursors on the catalytic performance of Cu1.5Mn1.5O4@N-C showed that the synergy between Cu and Mn sites promoted the catalytic activity. XPS and H2-TPR characterizations further proved that the strong Cu-Mn interaction caused Mn species easier to donate electrons to PMS and Cu species easier to accept electrons from PMS. Through investigation of continuous flow BPA wastewater removal, the influence of coexisting anions and catalyst cycling stability, it was clearly demonstrate that the present system had broad application prospects. The degradation pathway and intermediate toxicity suggested that the current system did not produce secondary pollution. Based on the results of EPR and capture experiments confirming that 1O2 was the main active species, a mechanism in PMS activation has been proposed. This work provides a new efficient and low cost catalyst for PMS activation towards refractory pollutants degradation.

Highly n-doped silicon nanowires (SiNWs) exhibit excellent hydrogen generation. Our results indicate three hydrogen generation possibilities, i.e. SiNWs oxidation, photocatalysis and the cleavage of dangling H bonds, are jointly responsible for the efficient hydrogen generation. Oxidation accounts for about 80% of total hydrogen, photocatalysis contributes less than 20% of total hydrogen, and about 0.1% of total hydrogen is from cleavage of dangling H bonds. SiNWs were oxidized in water and form SiOx (0 < X < 2) thin layer. Furthermore, the ratio of photo-generated hydrogen to photo-generated oxygen is about 2.4:1. It suggests that photocatalysis appears to be a process of water splitting. This study is significant to reveal the mechanism of hydrogen production on SiNWs prepared by Metal-Assisted Wet Chemical Etching (MAWC).

Fenton-like technology can efficiently remove recalcitrant pollutants, but developing catalytic oxidation system for deep mineralization of pollutants remains a challenge. Therefore, Cu-Mn spinel oxide nanospheres anchored N-doped carbon (CMO/NC) was prepared by a one-step calcination method and used to activate peroxymonosulfate (PMS) for efficient mineralization of bisphenol A (BPA). With the use of 0.5 g/L CMO/NC and 0.2 g/L PMS, the added BPA (50 mg/L) was completely degraded and deeply mineralized (nearly 95.2 %) in 9 min. The apparent first-order degradation rate constant k was 0.557 min(-1), which was 61.9, 6.2 and 2.5 times than those in the systems of N-C/PMS (0.009 min(-1)), CuO/NC/PMS (0.09 min(-1)) and Mn3O4/NC/PMS (0.22 min(-1)). A comparison between the catalytic performances of CMO/NC catalysts prepared by changing the dosage of urea confirmed the catalysis synergism between Cu-Mn spinel oxides and N-C. A further comparison between the catalytic performances of CMO/NC catalysts prepared by varying the Cu/Mn molar ratio of the precursors showed that the synergy between Cu and Mn sites promoted the catalytic activity, with a synergistic effect factor of 1.8. XPS and H-2-TPR characterizations proved that strong Cu-Mn interaction caused Mn species easier to donate electrons to PMS and Cu species easier to accept electrons from PMS. The degradation pathway and intermediate toxicity suggested that the system did not produce secondary pollution. Based on the results of EPR and capture experiments confirming that O-1(2) was the major active species, a mechanism on PMS activation was proposed. Through investigations of continuous flow BPA wastewater removal, the influence of coexisting anions and catalyst cycling stability, it was clearly demonstrated that the present system had broad application prospects.

The magnetic CuFeO2 anchored on nitrogen-doped porous carbon (CuFeO2/NC) hybrid catalysts were further synthesized via hydrothermal reaction without the addition of a chemical reductant. The systematic CuFeO2/NC with larger specific surface areas (SSAs) and abundant active sites exhibited strong adsorption ability and great catalytic performance towards activating peroxymonosulfate (PMS) for sulfamethoxazole (SMX) removal. It was noted that 18 mg/L SMX was completely removed after 40 min of pre-adsorption and 30 min of oxidative degradation in CuFeO2/NC and PMS system. The degradation rate constant (k) was calculated by fitting as 0.166 min-1, being about 7.9 times that in the CuFeO2 and PMS system (0.021 min-1). The SO4 & BULL;-,& BULL;OH, and 1O2 as the dominant reactive oxygen species (ROSs) contributed to sulfamethoxazole degradation. The N species, active oxygen and the redox cycles of Cu(II)/Cu(I) and Fe(III)/Fe(II) were confirmed to play a vital role in the activation of PMS for the generation of ROSs. Based on the LC-MS analysis, the possible degradation routes of SMX in the PMS activation system by CuFeO2/NC were proposed.

Core–shell ZIFs wrapped CuO hybrid materials (CuO@ZIF-67(Co)) were designed, synthesized, characterized, and employed as peroxymonosulfate (PMS) activators to degrade methylene blue (MB). It demonstrated outstanding catalytic activity on account of the unique structure and the synergistic effect between CuO cores and ZIF-67(Co) shells, resulting in complete degradation of MB (10 mg/L) in 1 min. Reactive oxygen species (ROSs) research showed that both SO 4 − and OH were responsible for the removal of MB. The synergistic activation mechanisms in the CuO@ZIF-67(Co)/PMS system were investigated, which mainly involved the effective electron transfer of CuO and ZIF-67(Co) for accelerating the cycle of Cu II /Cu I and Co III /Co II . This study broadens the application of MOF-derived materials for wastewater treatment.

Polyacrylonitrile (PAN)-based composite nanofibers incorporated with high-percentage inexpensive pitch were successfully prepared by a simple electrospinning technique. Low-softening-point naphthalene pitch (NP) has the merit of high solubility but inevitably brings about preoxidation problem. Thus the influence of different preoxidation strategies on the morphology, composition, and structure of composite nanofibers was systematically investigated. The results show that there exists a ternary phase diagram consisting of PAN-pitch-solvent and a suitable apparent viscosity of homogeneous solution, which favors the smooth electrospinning and good adjustment for the diameter of carbon nanofibers (100-500 nm). The crystallinity, crystalline order, and electrical conduction of composite nanofibers are enhanced by incorporating graphitizable NP, for example, the electrical resistance of 50% NP-PAN composite nanofiber films after 800 degrees C carbonization decreases about 30%. Both increasing the oxidation temperature and extending the oxidation time are beneficial to the oxidative stabilization of composite nanofibers with a suitable NP percentage below 50%. Gradient heating (240-340 degrees C) and pressurized (0.08 MPa) preoxidations could accelerate the oxidative stabilization of composite nanofibers with a high NP percentage up to 110% and significantly shorten the oxidation time by half. Therefore, this study paves the road for facile preparation of cost-competitive carbon nanofibers with controllable morphology, structure, and properties.

A novel CuO-Fe3O4 encapsulated in the carbon framework with abundant oxygen vacancies (CuO-Fe3O4@C) was successfully prepared by thermal conversion of Cu(OAc)2/Fe-metal organic framework. The as-prepared catalyst exhibited excellent peroxymonosulfate (PMS) activation performance, good recyclability and fast magnetic separation. Under optimal conditions, the added BPA (60 mg/L) could be completely removed by CuO-Fe3O4@C/PMS system within 15 min with the degradation rate constant (k) of 0.32 min- 1, being 10.3 and 246.2 times that in CuO/PMS (0.031min- 1) and Fe3O4/PMS (0.0013 min- 1) system. A deep mineralization rate of BPA (>80%) was achieved within 60 min. The results demonstrated the synergistic effect of bimetallic clusters, oxygen vacancies and carbon framework was a key benefit for the exposure of more active sites, the electron donor capacity and the mass transfer of substrates, thereby promoting the decomposition of BPA. Capture experiments and EPR indicated that 1O2 was the predominant reactive oxygen species (ROSs). The degradation routes of BPA and the activation mechanism of PMS were proposed. This study offers an opportunity to develop promising MOFs-derived hybrid catalysts with tailored structures and properties for the practical application of SR-AOPs.

Transition metal nanoparticles supported on porous carbon materials as hydrothermal stable and highly effective catalysts are increasingly attracting worldwide attention. Herein, a controllable electrospinning technique was employed to prepare the promising catalysts to produce hydrogen. Different proportions of polymethyl methacrylate and nickel nitrate were introduced into polyacrylonitrile spinning solution to prepare nano scale Ni encapsulated in porous carbon nanofiber (Ni@PCNF) through an in-situ pore making strategy. The results show that the prepared 10 wt% Ni@PCNF catalyst possesses an enhanced specific surface area, hierarchical porous structure, and uniformly-dispersed Ni nanoparticles (-17 nm). This porous and fibrous catalyst presents relatively high performance of producing high-purity H2 by aqueous phase reforming of glycerol compared with several reference catalysts on different supports (e.g., activated carbon fibers and g-Al2O3) under similar reaction conditions. The selectivity and purity of H2 produced by 10 wt % Ni@PCNF catalyst at 260 degrees C for 1 h are nearly 100% and 93%, respectively. This is related to the moderate catalytic activity of active Ni nanoparticles encapsulated in PCNFs. By contrast, those Ni nanoparticles supported on the reference supports show a high catalytic activity and thus produce low-purity H2 due to the considerable byproducts of CH4, CO and CO2. Moreover, Ni@PCNF catalyst exhibits a good structure stability and reuse effect in comparison with reference catalysts. This work provides a roadmap for preparing effective and stable Ni-based catalysts to produce high-purity H2 from cheap glycerol through a low temperature thermocatalysis. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

ESR (Ethanol steam reforming) seems to be a promising way to produce hydrogen which has been proposed as the most desirable energy carriers to overcome the problem of fossil fuels shortage. The ESR mechanism on the optimized Co10|alpha-Al2O3 (0001) surface is investigated by means of DFT calculations. The results show that oxidation state of Co cluster and micro-chemical environment play important roles in the ESR reaction. C-C bond scission is favored on the Co0 site while C-O bond scission is likely to happen on the Cox+ site, and the energy barrier is influenced by the number of hydrogen and oxygen atoms that are bonded with C/O atom. ESR reaction is initiated by the O-H bond scission of ethanol on the Cox+ site: CH3CH2OH*-> CH3CH2O*-> CH3*+CH2O*->-CH2O*+OH*-> H2COOH*-> COOH*+H2*-> CO*+H2*with the dehydrogenation of H2COO* as the rate -determining step.

Nano-sized NiCo2O4 powders were prepared by a facile hydrothermal method. The phase structure, particle morphology, specific surface area and pore size distribution of the powders were examined as a function of their calcination temperature. In view of utilization in supercapacitors, the electrochemical properties of the electrodes prepared from the powders were investigated by means of cyclic voltammetry, galvanostatic chargedischarge and electrochemical impedance spectroscopy techniques. In addition, the electrochemical properties of the electrodes were tentatively interpreted with respect to the kinetics parameters of electrons and ions involved in the electrode reaction. The NiCo2O4 powder calcined at 350 degrees C displayed nanorod morphology (30-50 nm in diameter and 200-400 nm in length) and optimal electrochemical properties among the investigated specimens. The electrode prepared from the powder displayed an outer voltammetric charge of 113 C/g and a charge transfer resistance of 0.39 omega together with a specific capacitance of 343 C/g under current density of 1 A/g and a capacitance retention of 108% after 5000 charge/discharge cycles measured at 20 A/g.

Highly n-doped silicon nanowires (SiNWs) decorated with silver nanoparticles (AgNPs) at the top, middle, and bottom were produced using electroless silver deposition (ELD), silver mirror reaction (MR), and native AgNPs as a reference, respectively. Subsequently, hydrogen generation on SiNWs decorated with and without AgNPs was evaluated. Our results show that SiNWs decorated with native and MR AgNPs produce the highest and the lowest hydrogen amount under white light irradiation in 3 h, respectively. Moreover, for SiNWs with native AgNPs, the morphology of SiNWs after hydrogen generation was almost the same as the original array of SiNWs before hydrogen release, even after 24 h in water/ethanol (4:1; v/v) solution. However, the geometry of SiNWs decorated without and with AgNPs by ELD and MR was collapsed after hydrogen evolution. The detailed surface studies show that the sidewall surface of SiNWs with native AgNPs has a rougher topology and formed a stable layer of SiOx in water. Our observations strongly suggest that two hydrogen generation possibilities, i.e., SiNW oxidation and photostimulation, are jointly responsible for the efficient hydrogen generation. Additionally, the presence of AgNPs on the sidewall of the SiNW matrix can enhance the hydrogen generation rate. Our results open novel perspectives for the effective hydrogen generation based on nanostructured silicon.

Single-atom Cu and N co-coordinated porous carbon (Cu-N-C) was synthesized by hydrothermal-calcination using zinc zeolite imidazole frameworks (ZIF-8) as the precursor. The catalyst showed excellent adsorption and catalytic ability due to the ideally-dispersed single atomic copper sites and the unique nitrogen-doped porous carbon. The complete removal of sulfamethoxazole (SMX, 18 mg/L) could be achieved within 40 min of pre adsorption and 25 min of oxidative degradation in the present of peroxymonosulfate (PMS). The adsorption capacity of Cu-N-C (0.2 g/L) was evaluated to be 58.69 mg/g. The apparent degradation rate constant (k) of SMX on Cu-N-C was 0.155 min(-1), which was 14.1 times faster than that on N-C (0.011 min(-1)). From the activation mechanism, it was found that CuN units acted as the main active sites in Cu-N-C for PMS activation. EPR analysis and quenching experiments verified that the reactive oxygen species (ROSs) of SO4 center dot- and O-1(2) were involved in the decomposition and mineralization of SMX. This work provides a new perspective for the development of Fenton like single-atom catalysts.

Nitrogen modified oxidized activated carbon (N-OAC) was prepared by nitric acid oxidation and ammonia hydrothermal treatment of activated carbon. The surface functional groups of AC were changed by controlling the synthetic conditions and characterized. It was found that oxygen and nitrogen functional groups was introduced on the surface of AC. The deeper degree of oxidation was in favour of N doping. With well-suited amount of oxygen and nitrogen modification, the adsorption and activation ability toward persulfate could be enhanced simultaneously. The adsorption experiment showed that the maximum adsorption capacity (q(m)) of N-OAC for bisphenol A (BPA) obtained from a Langmuir isotherm was 147 mg g(-1) at 298 K, which was about 1.23 and 1.5 times than that of AC (121 mg g(-1)) and N-free-OAC (108 mg g(-1)). N-OAC could also activate persulfate, producing strong oxidizing sulfate radicals. The apparent degradation rate constant of BPA on N-OAC was 0.039 min(-1), being about 39 times than that (0.001 min(-1)) on AC. After adsorption equilibrium within 120 min, the use of N-OAC (240 mg L-1) and persulfate (4 mmol L-1) almost completely removed the added bisphenols (60 mg L-1) at pH 6.6 within 60 min. A synergistic effect and correlation between the adsorption ability, catalytic performance and chemical structures of N-OAC was discussed.

工程教育认证以产出导向(OBE)作为核心理念,为高等教育提供了教育质量保证.湖北理工学院化学工程与工艺专业按照专业认证体系标准要求,从培养目标的制订依据、制订与形成以及评价和改进3个方面进行了探讨和实践.通过持续改进,使培养目标更趋于合理,使培养目标顺利达成.

Polycarbosilane, B-Si and B-Si-Zr modification coal tar pitch were used as impregnate agent for infiltration and pyrolysis formation of carbon/carbon (abbreviated as C/C) composites with B4C-SiC-ZrC-ZrB2 coating. The density of the composites was examined to be 1.0 g center dot cm(-3), 1.4 g center dot cm(-3) and 1.8 g center dot cm(-3), respectively. The phase compositions, surface morphologies and element distributions of the coating were analyzed by X-ray diffraction (XRD) scanning electron microscopy (SEM) and energy dispervive spectroscopy (EDS), respectively. The result showed that the two composites with a density of 1.4 g center dot cm(-3) and 1.8 g center dot cm(-3) displayed compact microstructures. The oxidation behavior of the composites was studied by oxidation in air at temperatures from 800 to 1,550 degrees C for 1 h. The composites with a density of 1.8 g center dot cm-3 exhibited a lower weight loss of 1.8 % after oxidation. B4C-SiC-ZrC-ZrB2 coating was found to provide the best protection by the precipitated B2O3, SiO2 and ZrO2 on the surface of the composites during the oxidation process, which were characterized by self-healing and antioxidation. The C/C composites with B4C-SiC-ZrC-ZrB2 coating performed well at high temperatures with the formation of complex oxides glass film that prevented oxygen from further spreading into the matrix.

A spinnable mesophase pitch with 95 vol.% optical anisotropy and 267 degrees C softening point was prepared through co-polymerization of 95 wt.% naphthalene pitch and 5 wt.% C9 resin. The effects of introducing C9 resin on the formation, structure and properties of naphthalene-derived mesophase pitch and the oxidative stabilization of resulting pitch fibers as well as the final physical properties of carbon fibers were systematically investigated. The results suggest that C9 resin could effectively facilitate the generation and development of liquid crystals in synthetic naphthalene pitch during the heat soaking process and introduce a certain amount of methyl side chains linking in polycyclic aromatic hydrocarbon molecules, so as to reduce the melt viscosity of modified mesophase pitch and improve its flow-spinnability and oxidative reaction capability. The pre-oxidation process of the modified pitch-spun fibers could be completed ahead of 4 h at 240 degrees C in an air atmosphere, compared with unmodified pitch fibers. This shows a possibility to decrease the production cost of mesophase pitch-based carbon fibers. Although the tensile strength of 1000 degrees C carbonized fibers prepared from the modified mesophase pitch (1.23 GPa) is slightly higher than that of original carbon fibers (1.18 GPa), the axial electrical resistivity and the thermal conductivity of corresponding graphite fibers after 3000 degrees C graphitization are 2.0 mu Omega m and 677 W/(m K), respectively, which are significantly enhanced in comparison with those of original graphite fibers (3.2 mu Omega m and 473 W/(m K).