Superactivity of Bimetallic CuFeO2 Submicron Particles towards Selective Proteolysis, Depending on Their Surface Hydroxyls.

Nano bimetallic oxides as nanoproteases have the great advantages in the heterogeneous hydrolysis of proteins. Here, we report that bimetallic delafossite CuFeO2 submicron particles (CuFeO2 SMPs) display a high protease activity towards selective cleavage of peptide bond involving hydrophobic residue at 25 centidegree. CuFeO2 SMPs have excellent regeneration performance with high structural stability. The strong Lewis acidity of Fe(III) and the strong nucleophilicity of Cu(I) bound hydroxyl groups are both necessary for the high protease activity of CuFeO2 SMPs. Low-valent metal ion has a great advantage in that low-valent Cu(I) bound hydroxyl has strong nucleophilicity, resulting in promotion of protein hydrolysis via high-efficient bimetallic catalysis. This study provides evidence that the protease activity of CuFeO2 SMPs depends on metal ion-bound hydroxyls on their surface. Our findings highlight that the valence of metal ions in artificial protease and their surface hydroxyls are two important factors that determine their catalytic efficiency.

Nitrogen-Tungsten Oxide Nanostructures on Nickel Foam as High Efficient Electrocatalysts for Benzyl Alcohol Oxidation.

Electrocatalytic alcohol oxidation (EAO) is an attractive alternative to the sluggish oxygen evolution reaction in electrochemical hydrogen evolution cells. However, the development of high-performance bifunctional electrocatalysts is a major challenge. Herein, we developed a nitrogen-doped bimetallic oxide electrocatalyst (WO-N/NF) by a one-step hydrothermal method for the selective electrooxidation of benzyl alcohol to benzoic acid in alkaline electrolytes. The WO-N/NF electrode features block-shaped particles on a rough, inhomogeneous surface with cracks and lumpy nodules, increasing active sites and enhancing electrolyte diffusion. The electrode demonstrates exceptional activity, stability, and selectivity, achieving efficient benzoic acid production while reducing the electrolysis voltage. A low onset potential of 1.38 V (vs. RHE) is achieved to reach a current density of 100 mA cm-2 in 1.0 M KOH electrolyte with only 0.2 mmol of metal precursors, which is 396 mV lower than that of water oxidation. The analysis reveals a yield, conversion, and selectivity of 98.41%, 99.66%, and 99.74%, respectively, with a Faradaic efficiency of 98.77%. This work provides insight into the rational design of a highly active and selective catalyst for electrocatalytic alcohol oxidation.

Engineering Fe and V Coordinated Bimetallic Oxide Nanocatalyst Enables Enhanced Polysulfides Mediation for High Energy Density Li-S Battery.

Lithium sulfur (Li-S) batteries are expected to become the next-generation rechargeable energy storage devices owing to their high theoretical energy density, environmental benignity, and economic benefits. However, the undesirable lithium polysulfides (LiPSs) shuttling and sluggish redox kinetics of sulfur electrochemistry severely degenerate the wide-ranging electrochemical performances, hindering the commercialization process of Li-S batteries. Herein, a Fe and V coordinated bimetallic oxide FeVO4 (denote FVO) nanocatalyst with three-dimensional (3D) ordered structure is thoughtfully tailored and cooperated with the commercialized carbon nanotubes (CNT) to modify polypropylene (PP) separator for achieving high efficiencies of restraining the LiPSs shuttling and boosting the redox conversion of sulfur species. The Fe and V coordinated bimetallic oxide demonstrates enhanced anchoring and catalyzing activities toward sulfur species than single metal oxides of Fe and V with homometallic valence states due to the reconfiguration of the 3d-band. Impressively, the Li-S pouch cell with the FVO/CNT@PP separator achieves an energy density up to 341 Wh kg-1 . The bimetallic oxide nanocatalyst used in this work enlightens a new designing route toward the separator modification for the development of high energy density Li-S batteries.

Microwave-Induced Deep Catalytic Oxidation of NO Using Molecular-Sieve-Supported Oxygen-Vacancy-Enriched Fe-Mn Bimetal Oxides.

A novel microwave (MW) catalytic oxidation denitrification method was developed, which can deeply oxidize NO into nitrate/nitrite with little NO2 yield. A molecular-sieve-supported oxygen-vacancy-enriched Fe2O3-MnO2 catalyst (Ov-Fe-Mn@MOS) was fabricated. Physicochemical properties of the catalyst were revealed by various characterization methods. MW irradiation was superior to the conventional heating method in NO oxidation (90.5 vs 70.6%), and MW empowered the catalyst with excellent low-temperature activity (100-200 °C) and good resistance to H2O and SO2. Ion chromatography analysis demonstrated that the amount of nitrate/nitrite accounted for over 90.0% of the N products, but the main product gradually varied from nitrate to nitrite as the reaction proceeded because of the switching of the main reaction path of NO removal. Mechanism analyses clarified that NO oxidation was a non-radical catalytic reaction: (i) the chemisorbed NO on ≡Mn(IV) reacted with O2* to produce nitrate and (ii) the excited NO* due to MW irradiation reacted with the active O* generated from Ov···O2 to form nitrite. Density functional theory calculations combined with electron paramagnetic resonance tests revealed the promotional effects of Fe2O3 in (i) boosting the Ov's quantity; (ii) facilitating O2 adsorption; (iii) increasing the nitrite formation; and (iv) alleviating the suppression of SO2.

Surface-engineered polyethersulfone membranes with inherent Fe-Mn bimetallic oxides for improved permeability and antifouling capability.

In recent years, bimetallic oxide nanoparticles have garnered significant attention owing to their salient advantages over monometallic nanoparticles. In this study, Fe2O3-Mn2O3 nanoparticles were synthesized and used as nanomodifiers for polyethersulfone (PES) ultrafiltration membranes. A NIPS was used to fabricate asymmetric membranes. The effect of nanoparticle concentration (0-1 wt.%) on the morphology, roughness, wettability, porosity, permeability, and protein filtration performance of the membranes was investigated. The membrane containing 0.25 wt% nanoparticles exhibited the lowest water contact angle (67°) and surface roughness (10.4 ± 2.8 nm) compared to the other membranes. Moreover, this membrane exhibited the highest porosity (74%) and the highest pure water flux (398 L/m2 h), which was 16% and 1.9 times higher than that of the pristine PES membrane. The modified PES membranes showed an improved antifouling ability, especially against irreversible fouling. Bovine serum albumin protein-based dynamic five-cycle filtration tests showed a maximum flux recovery ratio of 77% (cycle-1), 67% (cycle-2), and 65.8% (cycle-5) for the PES membrane containing 0.25 wt% nanoparticles. Overall, the biphasic Fe2O3-Mn2O3 nanoparticles were found to be an effective nanomodifier for improving the permeability and antifouling ability of PES membranes in protein separation and water treatment applications.

Constructing Morphologically Tunable Copper Oxide-Based Nanomaterials on Cu Wire with/without the Deposition of Manganese Oxide as Bifunctional Materials for Glucose Sensing and Supercapacitors.

Morphologically tunable copper oxide-based nanomaterials on Cu wire have been synthesized through a one-step alkali-assisted surface oxidation process for non-enzymatic glucose sensing. Subsequently, copper oxide-based nanomaterials on Cu wire as a supporting matrix to deposit manganese oxide for the construction of heterostructured Mn-Cu bimetallic oxide architectures through spontaneous redox reaction in the KMnO4 solution for supercapacitors. Field emission scanning electron microscopy (FESEM), field emission transmission electron microscopy (FETEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) confirmed that morphological and phase transformation from Cu(OH)2 to CuO occurred in copper oxide-based nanomaterials on Cu wire with different degrees of growth reaction. In non-enzymatic glucose sensing, morphologically tunable copper oxide-based nanomaterials owned the high tunability of electrocatalytically active sites and intrinsic catalytic activity to meet efficient glucose electrooxidation for obtaining promoted non-enzymatic glucose sensing performances (sensitivity of 2331 µA mM-1 cm-2 and the limit of detection of 0.02 mM). In the supercapacitor, heterostructured Mn-Cu bimetallic oxide-based nanomaterials delivered abundant redox-active sites and continuous conductive network to optimize the synergistic effect of Mn and Cu redox species for boosting the pseudo-capacitance performance (areal capacitance value of 79.4 mF cm-2 at 0.2 mA cm-2 current density and capacitance retention of 74.9% after 1000 cycles). It concluded that morphologically tunable copper oxide-based nanomaterials on Cu wire with/without deposition of manganese oxide could be good candidates for the future design of synergistic multifunctional materials in electrochemical techniques.

Bimetallic modified halloysite particle electrode enhanced electrocatalytic oxidation for the degradation of sulfanilamide.

The treatment of antibiotics wastewater by electrocatalytic oxidation has attracted much attention. In the paper, a novel halloysite bimetallic (HLS-Cu-Mn) particle electrode material was prepared and a bench-scale electrocatalytic reaction tank was designed. A three-dimensional electrocatalytic oxidation reactor composed of HLS-Cu-Mn and a bench-scale electrocatalytic reaction tank was used to degrade Sulfanilamide (SA) wastewater. Characterization of the synthesized material was conducted with Scanning electron microscopy (SEM), X-ray polycrystalline powder diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET). The electron spin resonance spectroscopy test results confirmed that HLS-Cu-Mn produced a large number of •OH. The electrochemical workstation confirmed that HLS-Cu-Mn had strong electrocatalytic activity and repolarization ability. Under the optimum preparation conditions and degradation process parameters, the removal efficiency of SA and TOC was 99.84% and 88.95% respectively. The method also has good degradation efficiency for aniline, phenol, herbicides, antibiotics, and dyeing wastewater. It was found that 4 main intermediates appeared in the degradation process by Ultra-high performance liquid chromatography/triple tandem quadrupole mass spectrometry (LC-MS). In sum, it was believed that this work provides a new vision and idea for water treatment.

3D, large-area NiCo2O4 microflowers as a highly stable substrate for rapid and trace level detection of flutamide in biofluids via surface-enhanced Raman scattering (SERS).

A one-pot hydrothermal synthesis of three-dimensional (3D), large-area, bimetallic oxide NiCo2O4 (NCO) microflowers has been developed as a novel substrate for surface-enhanced Raman scattering (SERS) detection of flutamide in biological fluids. The 3D flower-like morphology of the NCO is observed via FESEM micrographs, while the orthorhombic phase formation is confirmed through XRD spectra. Due to the presence of multiple coordination cations of the 3D NCO microflowers (such as Ni2+ and Co2+), the high surface area and surface roughness, the NCO-modified indium tin oxide (NCO/ITO) SERS substrate exhibits a linear detection range from 0.5-500 nM with a low limit of detection (LOD) of 0.1 nM. The SERS substrate provides a high enhancement factor of 1.864 × 106 with an accumulation time of 30 s using a laser source of λ = 532 nm, which can be ascribed to the excellent and rapid interaction between the flutamide molecule and the NCO microflower substrate that leads to photoinduced charge transfer (PICT) resonance. The NCO/ITO substrate exhibits excellent homogeneity and high chemical stability. Besides, the substrate displays an excellent selectivity to flutamide molecules in the existence of other metabolites such as urea, ascorbic acid (AA), glucose, NaCl, KCl, CaCl2, and hydroxyflutamide. The NCO/ITO substrate is successful in the trace-level detection of flutamide in simulated blood serum samples. The strategy outlined here presents a novel strategy for the efficacy of transition metal oxides (TMOs) based electrodes useful for a wide variety of bioanalytical applications.

Bimetallic oxide MnFe2O4 modified carbon felt anode by drip coating: an effective approach enhancing power generation performance of microbial fuel cell.

The anode electrode of microbial fuel cell (MFC) is the key component to determine its power generation performance because it is the habitat and electron transfer center of the electricity-producing microorganisms. Carbon-based anodes have been confirmed to improve MFC performance. Its large surface area, excellent conductivity and low cost make it very suitable for electrode materials used in MFC. However, the low biocompatibility and instability of common carbon-based materials restrict their practical application in MFC. In this work, a bimetal oxide MnFe2O4 was prepared and used to modify carbon felt anode by a simple drop coating method. The influence of the amount of MnFe2O4 material on the performance of MFC was systematically studied. The results showed that the power density of the carbon felt anode with a MnFe2O4 modified amount of 1 mg/cm2 increased by 66.9% compared with the unmodified anode. Meanwhile, the MFC cycle using MnFe2O4 modified anode was more stable. After 6 months of long-term operation, the power density reached 3836 mW/m2. The anode modified by MnFe2O4 has capacitance characteristics, good biocompatibility and fast electron transmission rate, which significantly improves the power generation performance of MFC. In addition, the use of a simple drop coating method to prepare electrodes can reduce the difficulty of electrode fabrication and the cost of MFC, laying a certain foundation for the industrialization of MFC.

Oxygen-Deficient Bimetallic Oxide FeWOX Nanosheets as Peroxidase-Like Nanozyme for Sensing Cancer via Photoacoustic Imaging.

Nanozymes with high catalytic activity and great stability have attracted increasing interests as the promising alternative to natural enzymes for applications in various fields. In this study, a new type of highly efficient peroxidase-like nanozymes based on FeWOX nanosheets (NSs) synthesized by a thermal-decomposition method is reported. Owing to the sheet-structure with maximized utilization of catalytic sites (Fe atoms and oxygen vacancies), such FeWOX NSs exert efficient enzyme activity to trigger catalytic decomposition of hydrogen peroxide (H2 O2 ) into hydroxyl radicals (•OH). A nanozyme-based ratio-metric nanoprobe is then fabricated by co-loading of 3,3,5,5-tetramethylbenzidine (TMB) and IR780 dye on FeWOX NSs to enable ratio-metric photoacoustic (PA) imaging of endogenous H2 O2 , as verified by imaging of the subcutaneous 4T1 xenograft tumor model and lipopolysaccharide (LPS)-induced inflammation model. Moreover, FeWOX NSs could also be employed as promising nanoagents for multimodal computed tomography (CT) and magnetic resonance (MR) imaging of tumors, due to the strong X-ray attenuation ability of W element and high MR contrast ability of Fe element, respectively. Importantly, FeWOX NSs with good biodegradability could be cleared out from the body without any significant biotoxicity. This work highlights bimetallic oxide FeWOX NSs as an enzyme-mimetic nanoplatform for imaging of the tumor microenvironment.

Sandwich-type electrochemical aptasensor for sensitive detection of myoglobin based on Pt@CuCo-oxide nanoparticles as a signal marker.

When an acute myocardial infarction (AMI) occurs, myoglobin (Mb) is the biomarker whose concentration firstly increases, and the high sensitive detection of Mb is critical for early diagnosis of AMI. Herein, a sandwich-type electrochemical aptasensor for the sensitive detection of Mb was constructed by using Pt@Cu1.33OCo0.83O as the signal marker. On one hand, nano-flower-like Cu1.33OCo0.83O was synthesized by hydrothermal method and Pt nanoparticles (Pt NPs) were loaded on its surface. Pt@Cu1.33OCo0.83O could immobilize aptamer 2 (Apt2) successfully by the Pt-S bond. And because of the synergistic effect between Pt and bimetallic oxide, Pt@Cu1.33OCo0.83O had an excellent catalytic effect on the signal source of hydrogen peroxide (H2O2) to amplify the current signal, which enhance the sensitivity of the aptasensor. On the other hand, the screen-printed gold electrode (SPGE) was used as the sensing base, which had good conductivity and ensured the immobilization of aptamer 1 (Apt1). The quantitative detection of Mb was achieved by specific recognition between Mb and Apt1, Apt2. As a result, the constructed electrochemical aptasensor had a good linear range (1-1500 ng/mL) with a low detection limit (LOD) of 0.128 ng/mL (S/N = 3), and a high sensitivity of 29.47 µA dec-1. The aptasensor also realized the detection of Mb in human serum samples with good accuracy, and the results were consistent with the hospital's biochemical indicators, which demonstrated the potential application of the prepared sensor in the clinical detection of Mb.

Ultrasonically assisted fabrication of electrochemical platform for tinidazole detection.

Based on sonochemistry, green synthesis methods play an important role in the development of nanomaterials. In this work, a novel chitosan modified MnMoO4/g-C3N4 (MnMoO4/g-C3N4/CHIT) was developed using ultrasonic cell disruptor (500 W, 30 kHz) for ultra-sensitive electrochemical detection of tinidazole (TNZ) in the environment. The morphology and surface properties of the synthesized MnMoO4/g-C3N4/CHIT electrode were characterized using X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and transmission electron microscope (TEM). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques were utilized to assess the electrochemical performance of TNZ. The results indicate that the electrochemical detection performance of TNZ is highly efficient, with a detection limit (LOD) of 3.78 nM, sensitivity of 1.320 µA·µM-1·cm-2, and a detection range of 0.1-200 µM. Additionally, the prepared electrode exhibits excellent selectivity, desirable anti-interference capability, and decent stability. MnMoO4/g-C3N4/CHIT can be successfully employed to detect TNZ in both the Songhua River and tap water, achieving good recovery rates within the range of 93.0 % to 106.6 %. Consequently, MnMoO4/g-C3N4/CHIT's simple synthesis might provide a new electrode for the sensitive, repeatable, and selective measurement of TNZ in real-time applications. Using the MnMoO4/g-C3N4/CHIT electrode can effectively monitor and detect the concentration of TNZ in environmental water, guiding the sewage treatment process and reducing the pollution level of antibiotics in the water environment.

Polybenzoxazine-Based Nitrogen-Containing Porous Carbon and Their Composites with NiCo Bimetallic Oxides for Supercapacitor Applications.

Supercapacitors (SCs) are considered as emerging energy storage devices that bridge the gap between electrolytic capacitors and rechargeable batteries. However, due to their low energy density, their real-time usage is restricted. Hence, to enhance the energy density of SCs, we prepared hetero-atom-doped carbon along with bimetallic oxides at different calcination temperatures, viz., HC/NiCo@600, HC/NiCo@700, HC/NiCo@800 and HC/NiCo@900. The material produced at 800 °C (HC/NiCo@800) exhibits a hierarchical 3D flower-like morphology. The electrochemical measurement of the prepared materials was performed in a three-electrode system showing an enhanced specific capacitance for HC/NiCo@600 (Cs = 1515 F g-1) in 1 M KOH, at a current density of 1 A g-1, among others. An asymmetric SC device was also fabricated using HC/NiCo@800 as anode and HC as cathode (HC/NiCo@600//HC). The fabricated device had the ability to operate at a high voltage window (~1.6 V), exhibiting a specific capacitance of 142 F g-1 at a current density of 1 A g-1; power density of 743.11 W kg-1 and energy density of 49.93 Wh kg-1. Altogether, a simple strategy of hetero-atom doping and bimetallic inclusion into the carbon framework enhances the energy density of SCs.

CoO/MoO3@Nitrogen-Doped carbon hollow heterostructures for efficient polysulfide immobilization and enhanced ion transport in Lithium-Sulfur batteries.

Lithium-sulfur batteries (LSBs) have emerged as a promising energy storage system, but their practical application is hindered by the polysulfide shuttle effect and sluggish redox kinetics. To address these challenges, we have developed CoO/MoO3@nitrogen-doped carbon (CoO/MoO3@NC) hollow heterostructures based on porous ZIF-67 as separators in LSBs. CoO has a strong anchoring effect on polysulfides. The heterostructure formed after the introduction of MoO3 increases the adsorption of polysulfides. The carbon coating outside the heterostructure improves the ion transmission efficiency of the battery, leading to enhanced electrochemical performance. The modified LSB demonstrates a low-capacity decay rate of 0.092% over 500 cycles at 0.5C, with a high discharge capacity of 613 mAh g-1 at 1C. This work presents a novel approach for the preparation of hollow heterostructure materials, aiming for high-performance LSBs.

Construction of Bimetallic-Anchored Two-Dimensional Nanosheets on COF for Rechargeable Zinc-Air Batteries.

The preparation of carbon materials by doping bimetallic oxides into triazine frameworks (COFs) is a promising electrocatalyst with the potential to replace precious metals in energy storage systems. In this experiment, a covalent triazine framework (COF) was synthesized by 1,4-dicyanobenzene (DCB) and zinc chloride, in which the COF and transition metals were used as carbon, nitrogen, cobalt, and iron sources. According to the properties of this COF, the destruction of the catalyst during pyrolysis can be prevented. The enhanced catalytic performance of the catalysts can be seen by testing all of the samples of catalysts in an alkaline medium. The high half-wave potential (E1/2) of 0.86 V is comparable to Pt/C and also shows excellent durability by testing. Zinc-air batteries were assembled using the prepared catalysts, and the batteries were tested for specific capacity (548 mAh g-1) and power density (189 mW cm-2). This work provides a new direction for COF-derived catalysts for carbon materials.

Unveiling CeZnOx Bimetallic Oxide: A Promising Material to Develop Composite SPPO Membranes for Enhanced Oxidative Stability and Fuel Cell Performance.

The incorporation of cerium-zinc bimetallic oxide (CeZnOx) nanostructures in sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) (SPPO) membranes holds promise in an enhanced and durable fuel cell performance. This investigation delves into the durability and efficiency of SPPO membranes intercalated with CeZnOx nanostructures by varying the filler loading of 1, 2, and 3% (w/w). The successful synthesis of CeZnOx nanostructures by the alkali-aided deposition method is confirmed by wide-angle X-ray diffraction spectroscopy (WAXS), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) analyses. CeZnOx@SPPO nanocomposite membranes are fabricated using a solution casting method. The intricate interplay of interfacial adhesion and coupling configuration between three-dimensional CeZnOx and sulfonic moieties of the SPPO backbone yields an enhancement in the bound water content within the proton exchange membranes (PEMs). This constructs simultaneously an extensive hydrogen bonding network intertwined with the proton transport channels, thereby elevating the proton conductivity (Km). The orchestrated reversible redox cycling involving Ce3+/Ce4+ enhances the quenching of aggressive radicals, aided by Zn2+, promoting oxygen deficiency and Ce3+ concentration. This synergistic efficacy ultimately translates into composite PEMs characterized by a mere 4% mass loss and a nominal 6% decrease in Km after rigorous exposure to Fenton's solution. Remarkably, an improved power density of 403.2 mW/cm2 and a maximum current density of 1260.6 mA/cm2 were achieved with 2% loading of CeZnOx (SPZ-2) at 75 °C and 100% RH. The fuel cell performance of SPZ-2 is 74% higher than its corresponding pristine SPPO membrane.

Cobalt based bimetallic catalysts for heterogeneous electro-Fenton adapting to vary pH for HEDP and MIT degradation.

Most of the materials studied as catalysts in the electro-Fenton system are variants of iron oxide or iron hydroxide. However, iron-based catalysts often exhibit weak catalytic capabilities under neutral and alkaline conditions. In this work, we synthesized three cobalt based bimetallic oxides, Co2CuOx, Co2AlOx, and Co2NiOx, using hydrothermal method and evaluated them as catalysts for the heterogeneous electro-Fenton system to remove 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) and Methylisothiazolinone [2-methyl-4-isothiazolin-3-one] (MIT). Co2NiOx has the highest catalytic degradation activity for HEDP, and Co2CuOx has the best catalytic degradation effect for MIT. Based on characterization results of the catalysts, the reasons for the differences in the pollutant removal efficiency were analysed, and the optimal pH for the three cobalt based oxides to remove HEDP and MIT was investigated. The results showed that the optimal pH values of the three cobalt based bimetallic oxides are not only influenced by the second metal type, but also by the properties of pollutants. Therefore, suitable cobalt based catalysts can be selected based on the different properties of pollutants, or the composition of cobalt based catalysts can be adjusted to meet the different pH requirements of target wastewater. The three cobalt based bimetallic oxides exhibited good degradation of HEDP and MIT under neutral conditions, which to some extent solved the problem of narrow pH range in the practical application of the electro-Fenton process.

Harnessing ZnCr2O4/g-C3N4 nanosheet heterojunction for enhanced photocatalytic degradation of rhodamine B and ciprofloxacin.

Utilizing semiconductors for photocatalytic processes in water bodies as an approach to environmental remediation has gained considerable attention. Theoretical band position calculations revealed a type-II step-scheme charge flow mechanism for ZnCr2O4/g-C3N4 (ZCr/gCN), emphasizing effective heterojunction formation due to synergies between the materials. A composite of agglomerated nanoparticle ZnCr2O4 (Zinc chromium oxide - ZCr)/g-C3N4 (graphitic carbon nitride - gCN) nanosheets was synthesized using the ultrasonication and leveraging the heterojunction to enhance degradation efficiency and active sites participation. The synthesized sample was characterized by XRD, XPS, FTIR, BET, HRSEM, EDX, HRTEM, EIS PL, and UV-visible spectroscopy. XRD analysis confirmed the successful formation of pure ZnCr2O4, g-C3N4 (gCN), and their composite without any secondary phases. Optical investigations demonstrated a red shift (444-470 nm) in UV-visible spectra as ZnCr2O4 content increased. Morphological assessment via HRSEM unveiled agglomerated nanoparticle and nanosheet structures. FTIR analysis indicated the presence of gCN with the tri-s-triazine breathing mode at 807 cm-1, and the identification of octahedral Zn-O (598.11 cm-1) and tetrahedral Cr-O (447.01 cm-1) metal bonds within the spinel structure of ZnCr2O4. A Surface area of 134.162 m2/g was noticed with a microporous structure of pore radius 1.484 nm. Notably, the 15% ZCr/gCN composite achieved a remarkable 93.94 % (Rhodamine B-RhB) and 74.36 % (Ciprofloxacin - CIP) within 100 and 120 min, surpassing the performance of pure gCN. Improved degradation was attributed to higher charge separation (photo-excited electrons and holes), reducing charge recombination, as supported by photoluminescence and photoelectrochemical analyses. The presence of active species like superoxide during degradation was confirmed through a scavenger test. The stability analysis confirms the sample's stable nature (without secondary phase formation) after degradation. This work underscores the potential of ZnCr2O4 based metal-free compounds intended for effective environmental remediation.

Progress and Prospect of Bimetallic Oxides for Sodium-Ion Batteries: Synthesis, Mechanism, and Optimization Strategy.

Sodium-ion batteries (SIBs) are considered as an alternative to and even replacement of lithium-ion batteries in the near future in order to address the energy crisis and scarcity of lithium resources due to the wide distribution and abundance of sodium resources on the earth. The exploration and development of high-performance anode materials are critical to the practical applications of advanced SIBs. Among various anode materials, bimetallic oxides (BMOs) have attracted special research attention because of their abundance, easy access, rich redox reactions, enhanced capacity and satisfactory cycling stability. Although many BMO anode materials have been reported as anode materials in SIBs, very limited studies summarized the progress and prospect of BMOs in practical applications of SIBs. In this review, recent progress and challenges of BMO anode materials for SIBs have been comprehensively summarized and discussed. First, the preparation methods and sodium storage mechanisms of BMOs are discussed. Then, the challenges, optimization strategies, and sodium storage performance of BMO anode materials have been reviewed and summarized. Finally, the prospects and future research directions of BMOs in SIBs have been proposed. This review aims to provide insight into the efficient design and optimization of BMO anode materials for high-performance SIBs.

Investigation on water defluoridation via batch and continuous mode using Ce-Al bimetallic oxide: Adsorption dynamics, electrochemical and LCA analysis.

With variable atomic ratios, Ce-Al bimetallic oxides were fabricated using the sol-gel combustion method and utilized for efficient fluoride removal. The synthesized bimetallic oxides were extensively studied using advanced characterization techniques, including TGA, XRD, FTIR, BET surface area analysis, EDX-assisted FESEM, XPS and impedance analysis. These techniques facilitate the interpretation of the chemical and physical properties of the synthesized material. The Ce-Al (1:1) bimetallic oxide was selected as an adsorbent for the defluoridation. The Ce-Al (1:1) oxide demonstrates a moderately high surface area of 108.67 m2/g. The sorption behaviour of fluoride on Ce-Al (1:1) was thoroughly investigated using batch and column modes. The maximum fluoride removal efficiency (99.4%) was achieved at a temperature of 45 °C and pH of 7.0 using an adsorbent dose of 0.18 g/L for 35 min. Pseudo-second-order kinetic model appropriately describes the sorption process. Freundlich's adsorption isotherm was more pertinent in representing fluoride adsorption behaviour. The maximum fluoride adsorption capacity is 146.73 mg/g at 45 °C. Thermodynamics study indicates fluoride adsorption on Ce-Al (1:1) bimetallic oxide is spontaneous and feasible. The adsorption mechanism was interpreted through XPS spectra, indicating that the physisorption process is mainly responsible for fluoride adsorption. An in-depth investigation of the adsorption dynamics was carried out using mass transfer models and found that the external diffusion process limits the overall adsorption rate. An electrochemical investigation was performed to understand the effect of fluoride adsorption on the electrochemical behaviour of bimetallic oxide. The fixed-bed column adsorption study suggested that the lower flow rate and increased bed height favourably impacted the overall defluoridation process, and column adsorption results were suitably interpreted through both the Adam-Bohart model and Yoon-Nelson dynamics model. The sustainable aspect of the defluoridation process was elucidated in terms of carbon footprint measurement using life cycle assessment analysis. The carbon footprint of the entire treatment process was calculated as 0.094 tons/year.