Adsorption Ability Research Articles

NiO-Incorporated Cu/Cu2O Nanowires for Highly Efficient Electrochemical Nitrate Reduction to Ammonia.

Electrochemical nitrate reduction to ammonia (NRA) is a promising sustainable way to synthesize ammonia (NH3) from nitrate (NO3-) contaminants. Cu-based electrocatalysts are frequently utilized for NRA due to their strong NO3- adsorption and de-oxygenation ability. However, this kind of catalyst usually possesses the weak water dissociation ability, resulting in insufficient proton supply in alkaline media to retard the following hydrogenation step of O-containing intermediates (*NOx, typically NO2-) to target NH3. Herein, NiO-incorporated Cu/Cu2O nanowires grown on nickel foam (p-CuNi@NF, p refers to plasma treatment) were synthesized via hydrothermal growth and subsequent O2 plasma treatment for efficient NRA electrocatalysis. On this p-CuNi@NF catalyst, NiO is able to accelerate the hydrogenation step by promoting the water dissociation to provide protons, ultimately facilitating efficient NRA. p-CuNi@NF exhibits excellent NH3 selectivity and yield in a wide potential range and reaches a high Faradaic efficiency (FENH3) of 97.5% and a yield (YNH3) of 470 μmol h-1 cm-2 at -0.6 V, both of which largely surpass the Cu/Cu2O catalyst.

Synthesis of bulk foam-like palygorskite based adsorbent for efficient and convenient recyclable removal of radioactive iodine and iodide

Radioactive iodine is the inevitable product of nuclear fission, and the types and valence states of iodine are relatively rich and easy to convert to each other. Therefore, the synthesis of a material that can be easily recovered and efficiently remove polyvalent radioactive iodine has great strategic significance for the safe use of nuclear power. Bulk foam-like palygorskite based adsorbents (PDMA-PAL) with the macroscopic pore size of 40 to 150 μm were synthesized by the emulsion template method using dimethylaminoethyl methacrylate (DMAEMA) as the functional monomer and cheap palygorskite (PAL) as the matrix material. The excessive addition of DMAEMA and PAL will lead to the collapse of the porous structure. Optimized PDMA2-PAL shows excellent adsorption capacity (2.14 g/g) for iodine in cyclohexane solution with the equilibrium time of 5 h. PDMA2-PAL also exhibits an excellent adsorption capacity for gaseous iodine (308 wt%), and the I2 adsorption mechanism is the strong affinity and charge transfer of electron-rich N heteroatoms for electron-deficient iodine. PDMA2-PAL also achieves an outstanding iodide adsorption capacity (2.1mmol/g) within 5 min, and the I− adsorption mechanism is the electrostatic interaction between I− and the derivatization of tertiary amine under acidic conditions. Moreover, the deprotonation in alkaline solution can desorb iodide efficiently, which makes PDMA-PAL exhibit excellent recyclability. Importantly, PDMA-PAL also shows excellent simultaneous adsorption ability of iodide and iodine, and also exhibits stable adsorption activity in actual water. This study provides promising results for the removal of polyvalent radioactive iodine by bulk foam-like palygorskite based adsorbent in environmental remediation.

Co-regulation of microstructure and intrinsic groups in carbon nitride to achieve high-efficient pollutant degradation under visible light: Roles of N species

Owing to the drawback of the lower separation and shorter lifetime of carriers in carbon nitride (CN), this study reported that the CN composites with different morphologies and the N species were successfully synthesized through the regulation of intrinsic functional groups. Results showed that the formed tubular structure in 1D CN nanotubes (1D CNNTs) could intensify the utilization of visible light (Vis) because of the multiple diffraction or scattering of light, bridge the mass transfer distance and provide more active sites. Meanwhile, 1D CNNTs showed excellent TC degradation rates (0.3777 min-1) under Vis, which were 13, 630 and 6-36 times higher than these of two-dimensional CN nanosheets, three-dimensional CN microspheres and reported CN based catalysts, respectively. The analysis of active species showed O2·- and h+ were the main active species for TC degradation. The degradation pathways and comprehensive toxicities of TC were also comprehensively analyzed. Theoretical calculation exhibited that the introduction of N vacancy and -NHx groups effectively accelerating separation of carriers, prolonging carrier lifetime and enhancing the adsorption ability and relative electron transfer of O2 to the production of O2·-. In addition, the prepared catalysts presented better stability and anti-interference ability. Therefore, this study would provide a new view for regulation of intrinsic functional groups in CN to achieve efficient pollutant degradation under Vis.

Self-assembled belt[12]pyridine nanotube for the adsorption and removal of anti-TB drugs from wastewater

Environmental safety is a major concern of today's world, and it has attracted the attention of the scientific research community. The environment gets contaminated due to various toxic drugs and pharmaceutical toxins coming from different sources. Therefore, removing these toxins is necessary for making the environment greener and safer. Nanomaterials are excellent candidates for adsorption and removal of harmful materials due to their unique properties. Herein we have studied self-assembled nanotube based on belt[12]pyridine (2-(12BPy)) as an adsorbent for the removal of antituberculosis drugs i.e. isoniazid (INZ) and pyrazinamide (PZA). The adsorption ability is studied by considering the adsorption energy (Eads), non-covalent interaction index analysis (NCI), quantum theory of atoms in molecules (QTAIM), energy decomposition analysis (EDA), charge transfer via natural bond orbital analysis (NBO) and electron localization function (ELF), and dipole moment. The results indicate strong adsorption of selected drugs with self-assembled nanotube without altering the electronic properties. Recovery time of the complexes is also calculated to understand the regeneration of the nanotube. Results also demonstrate that van der Waals forces are major contributor in the adsorption of drug molecules within the nanotube. Our results indicate that belt[12]pyridine (2-(12BPy)) nanotube can be used as an adsorbent for the removal of toxic drug molecules from the environment. This research will benefit the scientists working in the field of new sensors for biological components and materials.

Removal of Acid Orange 7 dye using Makgeolli lees with ultrasonic assistance

AbstractThis study investigated the efficient removal of Acid Orange 7 (AO7) dye in water by using Makgeolli lees, a popular by‐product obtained during the production of traditional Makgeolli beverages in Korea. By incorporating ultrasound, the effects of contact time, Makgeolli lees dosage, initial AO7 dye concentration, and initial pH of the dye solution were investigated and comprehensively compared with the same experiment using the stirring method. The results consistently showed ultrasound not only enhances the excellent adsorption ability of Makgeolli lees but also accelerates the process compared to the stirring method. The Langmuir isotherm model best described the adsorption process for both methods, suggesting monolayer adsorption on the surface of Makgeolli lees, with maximum capacities of 25.13 mg/g for ultrasound at 40 kHz and 20.41 mg/g for stirring methods. Furthermore, the study showed that optimal dye removal efficiency can be achieved with ultrasound conditions at 28 kHz frequency, 125 W/L power density, and 100% ultrasound intensity. This research promises that the integration of low‐cost biomass coupled with ultrasound could provide a potential solution for dye wastewater treatment.

Comparative Study on Ethanol-Based Oxygenate Synthesis via Syngas over Monometallic Rh Catalysts Supported on Different Zr-MOFs

Three types of Zr-based metal–organic frameworks (Zr-MOFs) were employed as supports to prepare monometallic Rh catalysts by the impregnation method. The effects of the structural properties of Zr-MOFs on their supported monometallic Rh catalysts for syngas conversion were investigated. The results showed that, compared to catalysts with Rh@MOF-808 and Rh@UiO-66, Rh@UiO-67 had higher CO conversion and C2+ oxygenate selectivity. The state of the Rh site is affected by the different structure of the Zr-MOFs, which is responsible for the difference in catalytic performance. The relatively higher Rh dispersion on the UiO-67 support boosted its CO adsorption ability, and Rh@UiO-67 having the best C2+ oxygenate selectivity was mainly attributed to it having the highest Rh+/Rh0 ratio.

Controllable synthesis of porous boron nitride fibers modified by cobalt and nickel oxides for efficient ceftriaxone sodium adsorption from aqueous solution.

Antibiotics can easily enter the water environment through direct or indirect approach, causing environmental pollution and endangering the health of organisms. Therefore, development of highly efficient adsorbent materials to adsorb and remove antibiotics is necessary. Here, cobalt oxide and nickel oxide are uniformly and tightly bonded on the surface of porous boron nitride fibers (PBNFs-NiCo), significantly increasing the number of functional groups (B-O and N-H) and hydrogen bond receptors within PBNFs. The total pore volume and specific surface area of resulting PBNFs-NiCo can reach up to 0.48 cm3/g and 720.3 m2/g, respectively. Encouraged by the unique micromorphology and chemical composition mentioned above, PBNFs-NiCo exhibits excellent ceftriaxone sodium (CS) adsorption ability, showing the adsorption capacity and removal efficiency up to 410.9 mg/g and 96.5%, respectively. Chemical adsorption plays an important role in their adsorption behavior, abiding by Langmuir adsorption theory and pseudo-second-order kinetic equation. Importantly, PBNFs-NiCo exhibits fascinating adsorption effects in surroundings with pH ranging from 4 to 6, 25 °C and varying salt concentrations. This work would establish a practical and feasible foundation for the practical application of PBNFs-NiCo for CS adsorption in aqueous solution.

Interaction of Pb(II) with microplastic-sediment complexes: Critical effect of surfactant

In this study, the impact of surfactants on the adsorption behavior of Pb(II) onto microplastics-sediment (MPs-S) complexes was investigated. Firstly, virgin polyamide (VPA) and polyethylene (VPE) were placed in Xiangjiang River sediment for six months to conduct in-situ aging. The results indicated that the biofilm-developed polyamide (BPA) and polyethylene (BPE) formed new oxygen-containing functional groups and different biofilm species. Furthermore, the adsorption capacity of Pb(II) in sediment (S) and MPs-S complexes was in the following order: S > BPA-S > VPE-S > VPA-S > BPE-S. The addition of sodium dodecyl benzenesulfonate (SDBS) promoted the adsorption of Pb(II), and the adsorption amount of Pb(II) increased with the higher concentration of SDBS, while adding cetyltrimethylammonium bromide (CTAB) showed the opposite result. The adsorption process of MPs-S complexes to Pb(II) was dominated by chemical adsorption, and the interaction between MPs-S complexes and Pb(II) was multilayer adsorption involving physical and chemical adsorption when the surfactants were added. Besides, the pH exerts a significant effect on Pb(II) adsorption in different MPs-S complexes, and the highest adsorption amount occurred at pH 6. Noteworthy, CTAB promoted the adsorption ability of Pb(II) when the exogenous FA was added. The binding characteristic of sediment endogenous DOM components and Pb(II) was influenced by the addition of MPs and surfactants. Finally, it confirmed that adsorption mechanisms mainly involve electrostatic and hydrophobic interaction. This study provides a new perspective to explore the environmental behaviors of Pb(II) by MPs and sediments with the addition of surfactants, which was conducive to evaluating the ecological risks of MPs and heavy metals in aquatic environments.

Hydration and microstructure formation of magnesium oxysulfate (MOS) cement regulated by sepiolite with high adsorption ability

Magnesium oxysulfate (MOS) cement is a potential low-carbon cementitious material with its characteristic depending on the reaction between light-burned magnesia (LBM) and MgSO4 solution. This work aimed to elucidate the effect of sepiolite with high adsorption ability on regulating the reaction within MOS cement. Replacement levels of LBM by sepiolite at 2 and 5 wt% were adopted. Hydration kinetics, microstructure, phase composition and compressive strength of MOS cement without and with sepiolite were studied. Results showed that adding sepiolite into MOS cement adjusted the ion distribution at the early hydration stage and promoted the reaction with an early onset of heat flow peaks. The presence of sepiolite refined the morphology of formed needle-like 5 Mg(OH)2·MgSO4·7H2O (517 phase) and strengthened the bond water within its structure. The high adsorption ability of sepiolite enabled the nucleation of 517 phase and amorphous phase onto its surface. Sepiolite also densified the poorly hydrated regions by tightly combining with the incompletely hydrated MgO grains. Consequently, compressive strength of MOS cement under air curing was improved after adding sepiolite.

Revealing the Mechanism of Converting CO2 into Methanol by the Cu2O and Oxygen Vacancy on MgO: Experiments and Density Functional Theory.

Given the great significance of defect and Cu compounds for the reduction of CO2 as well as the few reaction mechanisms of converting CO2 into different hydrocarbons, the effects of oxygen vacancies and Cu2O on the reduction of CO2 were thoroughly investigated, and possible mechanisms were also proposed. A series of Cu2O/Ov-MgO catalysts were synthesized for photothermal catalytic reduction of CO2 to methanol under visible-light irradiation, among which the 7%Cu2O/Ov-MgO composite exhibited the best reduction activity and the yield of methanol was 19.78 μmol·g-1·h-1. The successful composite of Cu2O and Ov-MgO can yield a loose and porous nanosheet, uniform distribution, favorable absorbance and photoelectric performance, and increased specific surface area and adsorption ability of CO2, which are all vital to the adsorption and conversion of CO2. The introduction of oxygen vacancy and Cu2O not only promotes the adsorption of CO2 but also provides more electron-triggered CO2 activation. Density functional theory (DFT) calculation was also performed to reveal the reaction mechanism for effective enhanced CO2 reduction to ethanol or methanol by the comparison of CuO/MgO and Cu2O/Ov-MgO composites, illustrating the reaction pathways of different products. By comparing the key steps in determining the selectivity of C1 or C2, the kinetic barriers of obtaining CH3OH for the Cu2O/Ov-MgO composite with CH3OH as the main product were found to be lower than those of generating CH2*, while the opposite is true for CuO/MgO composites, whereby it may be easier to obtain more C2 products. These insights into the reaction mechanism of converting CO2 into different hydrocarbons are expected to provide guidance for the further design of high-performance photothermal catalytic CO2 reduction catalysts.

Synergistic effect of Cerium and Niobium enhances the low-temperature NH3-SCR activity of Fe-containing solid waste

To develop environment-friendly low temperature NH3-SCR catalyst and realize the resource utilization of industrial solid waste, this research prepared a series NH3-SCR catalysts by using Fe-containing solid waste loading CeO2 and Nb2O5. It was found that the Ce2Nb1/Fe-Si catalyst exhibited the highest NH3-SCR activity, reaching about 93 % NOx conversion and 99 % N2 selectivity at 300 °C due to the synergistic effect between Ce and Nb species. The characterization results showed that the interaction between Ce and Nb was stronger than that between Nb and Fe species, promoting the NH3 adsorption and redox cycle of Ce4+ + Nb4+ ↔ Ce3+ + Nb5+, Ce3+ + Fe3+ ↔ Fe2+ + Ce4+, which increased the contents of Fe2+ and surface adsorbed oxygen. Moreover, the co-existence of Ce and Nb species would increase the NOx adsorption ability and promote the oxidation of NO to NO2, which was beneficial for “Fast SCR” reaction. Finally, the introduction of CeO2 and Nb2O5 did not changed the reaction mechanism, followed by a Langmuir-Hinshelwood mechanism.

Eco-friendly thiol-functionalized magnetic oxygenous carbon nitride nanocomposites for effective elimination of heavy metals

The increased pollution of water resources by toxic heavy metals poses a huge threat to the aqueous ecosystem. Since the low concentrations of heavy metals are often highly toxic but difficult to remove, novel efficient adsorbents still need to be explored. Herein, the superparamagnetic thiol-functionalized oxygenous carbon nitride nanocomposite (CNO/Fe3O4-SH) with multifunctional groups such as –NH2, –OH, –SH, and –COOH was fabricated by a simple and eco-friendly method. The maximum adsorption capacities of Pb2+, As3+, and Cd2+ ions on CNO/Fe3O4-SH at pH = 6 were 80.79, 71.78 and 66.19 mg/g, respectively, when their equilibrium concentrations were 20 mg/L. Under the equilibrium concentration below 0.01 mg/L, the adsorption capacities of these heavy metals over CNO/Fe3O4-SH were much higher than those of other adsorbents. The competitive adsorption investigations showed that the adsorption order in polymetallic solutions was Pb2+ > As3+ > Cd2+. Adsorption kinetics and isotherms studies indicated that the adsorption of Pb2+, As3+ and Cd2+ by CNO/Fe3O4-SH was attributed to monolayer adsorption and the adsorption process was controlled by chemical adsorption. The thermodynamic experiments showed that the adsorption processes were spontaneous and endothermic. After six adsorption/desorption cycles, CNO/Fe3O4-SH maintained its original morphology and adsorption ability, indicating its excellent regeneration performance, which had significant potential application in the decontamination of trace heavy metal ions in water.

Controlled Defective Engineering on CuIr Catalyst Promotes Nitrate Selective Reduction to Ammonia.

Electrochemical nitrate reduction reaction (NO3-RR) is a promising low-carbon and environmentally friendly approach for the production of ammonia (NH3). Herein, we develop a high-temperature quenched copper (Cu) catalyst with the aim of inducing nonequilibrium phase transformation, revealing the multiple defects (distortion, dislocations, vacancies, etc.) presented in Cu, which lead to low overpotential for NO3-RR and high efficiency for NH3 production. Further loading a low content of iridium (Ir) species on the Cu surface improves the reactivity and ammonia selectivity. The resultant CuIr electrode exhibits a Faradaic efficiency of 93% and a record yield of 6.01 mmol h-1 cm-2 at -0.22 VRHE exceeding those of state-of-the-art NO3-RR catalysts. Detailed investigations have demonstrated that the synergistic effect between multiple defects and Ir decoration effectively regulate the d-band center of copper, change the adsorption state of the catalyst surface, and promote the adsorption and reduction of intermediates and reactants. The strong H* adsorption ability of the Ir element provides more active hydrogen for the generation of ammonia, promoting the reduction of nitrate to NH3.

MOF-5 anchored polymer@carbon core–shell nanofibers for efficient removal of chlortetracycline from aqueous solution

Antibiotics excreted by human or animal may contain un-degradable residues, which form high concentration accumulation in water, leading to seriously harmful effects on the environment. Herein, MOF-5 anchored polymer@carbon core–shell nanofibers (MAPC) are fabricated via the electrospinning-hydrothermal synthesis and used for high efficiency removing chlortetracycline (CTC) from water. The anchored MOF-5 enhances the adsorption ability of hydrothermal carbon core–shell nanofibers. The MAPC nanofibers exhibit 395.87 mg/g of adsorption capacity for CTC removal process, which well fitted with Freundlich isotherm model and pseudo-second-order kinetic model. After nanofiber membrane filtering, the removal efficiency of CTC is nearly 100 % at the concentration of 5 mg/L. And the chemical oxygen demand (COD) concentration of CTC is reduced from 156.72 mg/L to 50.39 mg/L, that is below the pharmaceutical wastewater discharge standard. In addition, MAPC exhibits high flux and good regeneration performance. This work gives a typical strategy of feasible preparation of high efficiency MOFs anchored carbon-based nanofiber adsorbent towards the pharmaceutical wastewater treatment.

Dual surface-modification by oleic acid and epoxy-based silane coupling agent providing cerium oxide nanoparticles as additive in pentaerythritol oleate with improved high-temperature adsorption performance and tribological properties

An epoxy-based silane coupling agent (KH560) was grafted onto the surface of oleic acid-modified cerium oxide (CeO2-OA) nanoparticles in order to improve the competitive adsorption ability of the anti-wear additives in ester oils and simultaneously hinder the additive desorption owing to thermal disturbance under high-temperature condition. The as-prepared oleic acid-epoxy silane co-modified cerium oxide (CeO2-OA/E) nanoparticles were characterized. The effect of temperature on the adsorption behavior of trityl phosphate (TCP, a commercial high-temperature antifriction agent), CeO2-OA and CeO2-OA/E in PETO was studied using a dissipative quartz microbalance. Their tribological properties as the additives in pentaerythritol oleate (PETO), a polar ester base oil, were evaluated with a four-ball machine and a ball-on-block friction and wear tester; and their tribomechanism was explored with respect to their adsorption behavior on rubbed steel surfaces at elevated temperatures. It was found that the secondary surface-capping of CeO2-OA by the KH560 silane coupling agent resulted in great increases in the surface potential (from 54 mV to 396 mV) and thermal stability as well (the thermal decomposition temperature rose from 185 °C to 254 °C). Among the tesetd lubricant additives, CeO2-OA/E exhibited the highest adsorption mass, because of the highest surface potential the chemisorption ascribed to the epoxy group of the silane coupling agent. Particularly, CeO2-OA/E added in PETO exhibited better friction reduction and anti-wear properties at 150 °C than CeO2-OA and TCP, because CeO2-OA/E added in PETO formed tribofilm composed of CeO2 and SiO2 with excellent thermal stability as well as friction-reduction and antiwear effects through stable chemical adsorption and tribochemical reaction at elevated temperatures.

A novel 3D hierarchical NiFe-LDH/graphitic porous carbon composite as multifunctional adsorbent for efficient removal of cationic/anionic dyes and heavy metal ions

Developing effective adsorbents for wastewater purification is crucial, as excessive emissions of toxic dyes and heavy metal ions have been proven harmful to ecosystems and human health. A NiFe-layered double hydroxide/graphitic porous carbon (NiFe-LDH/GPC) composite was fabricated by introducing NiFe-LDH nanosheets into GPC via a simple hydrothermal method to utilize the advantages of both materials fully, and thus ultimately obtain a composite adsorbent with improved adsorption properties. The samples obtained were comprehensively characterized by various characterization means, and the effects of several critical influential factors on the pollutant uptake capability of the NiFe-LDH/GPC were also studied through batch experiments. The results show that the as-synthesized NiFe-LDH/GPC exhibits a three-dimensional (3D) fluffy ultrathin-wall hierarchical porous structure, which possesses a high specific surface area and pore volume separately up to 506.74 m2/g and 0.22 cm3 g−1 as well as a relatively narrow pore size distribution. These characteristics bring advantages to enhance the adsorption ability of the NiFe-LDH/GPC for cationic/anionic dyes and heavy metal ions such as congo red (CR), malachite green (MG) and hexavalent chrome (Cr(VI), which reached the maximum adsorption capacity of 1726.51 mg/g, 1157.11 mg/g and 155.72 mg/g under the optimum conditions, respectively. Meanwhile, the adsorption behavior can be well described by the pseudo-second-order kinetic model and Langmuir isotherm model, reflecting that the sorption process mainly occurred chemically in the adsorbent monolayer. Furthermore, the NiFe-LDH/GPC maintained relatively high adsorption performance after multicycle testing, manifesting its good recyclability and stability.

Toluene-Poisoning-Resistant High-Entropy Non-Noble Metal Anode for Direct One-Step Hydrogenation of Toluene to Methylcyclohexane.

The direct one-step hydrogenation of toluene to methylcyclohexane facilitated by a proton-exchange membrane water electrolyzer driven by renewable energy has garnered considerable attention for stable hydrogen storage and safe hydrogen transportation. However, a persistent challenge lies in the crossover of toluene from the cathode to the anode chamber, which deteriorates the anode and decreases its energy efficiency and lifetime. To address this challenge, the catalyst-poisoning mechanism is systematically investigated using IrO2 and high-entropic non-noble-metal alloys as anodes in acidic electrolytes saturated with toluene and toluene-oxidized derivatives, such as benzaldehyde, benzyl alcohol, and benzoic acid. Benzoic acid plays an important role in polymer-like carbon-film formation by blocking the catalytically active sites on the anode surface. Moreover, Nb and the highly entropic state on the surface of the multi-element alloy lower the adsorbing ability of toluene and prevent polymer-like carbon film formation. This study contributes to the design of catalyst-poisoning-resistant anodes for organic hydride technology, advanced fuel cells, and batteries.

Integrated doped-Ru electrocatalyst with excellent H adsorption–desorption and active site on hollow tubular structures for boosting efficient hydrogen evolution

Electrochemical water splitting for hydrogen production is an ideal process for clean energy production. However, highly active and low-cost electrocatalysts are essential and challenging. In this work, a multi-component Cu-based catalyst (Ru-M-C-Cu), synergized with ruthenium (Ru) heteroatom doping, was synthesized via a facile immersion-calcination-immersion method. Based on the cotton biomass substrate, a hollow tubular structure was obtained. By virtue of its distinctive structure and high carbon content, cotton biomass assumed a dual role as a sacrificial template and a reducing agent in the eco-friendly synthesis of electrocatalysts, which was instrumental in the creation of a multi-component system augmented by heteroatom doping. The multi-component system was constructed by in-situ transformation and redox reaction during calcination in an oxygen-free environment. The Ru-M-C-Cu catalyst exhibited a competitive overpotential of 108 mV at a current density of 10 mA cm−2 for alkaline hydrogen evolution reaction (HER). The satisfactory catalytic performance of Ru-M-C-Cu can be attributed to the fact that the Ru-O-Cu catalytic centers enhanced the adsorption and desorption abilities of the Cu–O active sites toward hydrogen. Furthermore, the hollow tubular structure allowed the electrolyte to make full contact with the active sites of the Ru-M-C-Cu catalyst, thus accelerated the HER kinetics. The catalyst showed structural and chemical stability after a 12-hour successive test. Besides, the production cost of Ru-M-C-Cu was significantly reduced by 99.1 % than that of commercial 20 % Pt/C, showing the potential as an alternative catalyst by offering a more accessible and sustainable source. This work provides a new design of sustainable low-budget electrocatalysts with the proposed strategies expected for producing clean and renewable hydrogen energy.

Anion vacancy engineering in carbon coating VS4 microspheres assembled by nanorod arrays for high-performance rechargeable Mg-Li hybrid batteries

Transition metal sulfides (TMSs) stand out as promising cathodes for rechargeable Mg-Li hybrid ion batteries (MLIBs) owing to their high theoretical capacity and rich redox chemistry. Nevertheless, it still faces great challenges involving the sluggish reaction kinetics and insufficient active sites, resulting in unsatisfactory stability and limited rate capability. And the role of anion vacancies on improving electrochemical properties of TMSs is still unclear. Herein, we have successfully designed an anion defect engineering strategy for the construction of carbon coating VS4 microspheres assembled by nanorod arrays (Sv-VS4@C-300) as the high-performance cathode for MLIBs. The systematic electrochemical tests together with theoretical calculations reveal that the sulfur vacancies simultaneously improve ion adsorption ability, facilitate charge transfer rate and boost reaction kinetics. Additionally, the open microsphere structure together with rich sulfur vacancies cooperatively provide more active sites and release the internal stress during cycling, thereby realizing the enhancement of capacity and structural stability. Consequently, these features enable Sv-VS4@C-300 with impressively high reversible capacity (485.1 mAh/g at 50 mA g−1) and exceptional long cycle lifespan (128.3 mAh/g at 2000 mA g−1 after 5000 cycles). This work implements an innovative strategy represented by anion vacancy engineering in the design of high-performance TMSs-based cathodes for rechargeable batteries.

A coordination polymer based on ionic-type ligand for efficient separation of C2H2/C2H4 and C3H4/C3H6 mixtures

C2–C3 alkyne/alkene adsorption and separation is a critical process in industrial production, but it remains challenging due to the similar size of gas molecules. Herein, based on an ionic-type ligand, a porous coordination polymer with inherent positive charged sites has been successfully constructed by 1D chains through non-conventional CH···O hydrogen bonds. The flexible framework shows adsorption ability for C2H2 while negligible adsorption of C2H4; and a much earlier steep increase for C3H4 isotherm compared to C3H6 isotherm in the low-pressure region. Ideal adsorbed solution theory further illustrated that the framework has the ability to separate C2H2/C2H4 and C3H4/C3H6 mixtures.