Acidic Media Research Articles

Study of the inhibitory properties of 2-((benzylthio)methyl)-1H-benzo[d]imidazole with respect to the corrosion of aluminum in a nitric acid medium

Due to its massive use, the behavior of aluminum in a 1 M nitric acid solution was studied in this work; this study which is mainly based on the inhibitory properties of 2-((benzylthio)methyl)-1H-benzo[d]imidazole (2-BTM1HBI) was carried out using the mass loss technique of temperature varying from 298 to 338 K and concentration of 10-3 mM at 5 mM. The inhibitory efficiency of 2-BTM1HBI increases with the increase of the concentration and this up to 96.09% but decreases with the increase of the temperature. The study of isotherms shows that the adsorption of the molecule studied on the surface of aluminum obeys the modified Langmuir isotherm (villamil model). The thermodynamic adsorption quantities were determined and discussed. They show that the adsorption of 2-BTM1HBI is spontaneous and exothermic with an increase in disorder. Adsorption is done in two modes: physisorption and chemsorption with a predominance of physisorption. The thermodynamic quantities of activation have shown that the dissolution process is endothermic with an increase in disorder.

High-Density Dual-Structure Single-Atom Pt Electrocatalyst for Efficient Hydrogen Evolution and Multimodal Sensing.

Herein, we report a high-density dual-structure single-atom catalyst (SAC) by creating a large number of vacancies of O and Ti in two-dimensional (2D) Ti3C2 to immobilize Pt atoms (SA Pt-Ti3C2). The SA Pt-Ti3C2 showed excellent performance toward the pH-universal electrochemical hydrogen evolution reaction (HER) and multimodal sensing. For HER catalysis, compared to the commercial 20 wt % Pt/C, the Pt mass activities of SA Pt-Ti3C2 at the overpotentials of ∼30 and 110 mV in acid and alkaline media are 45 and 34 times higher, respectively. More importantly, during the alkaline HER process, an interesting synergetic effect between Pt-C and Pt-Ti sites that dominated the Volmer and Heyrovsky steps, respectively, was revealed. Moreover, the SA Pt-Ti3C2 catalyst exhibited high sensitivity (0.62-2.65 μA μM-1) and fast response properties for the multimodal identifications of ascorbic acid, dopamine, uric acid, and nitric oxide under the assistance of machine learning.

Versatility of Juçara (Euterpe edulis) extracts as corrosion inhibitors of mild steel in different environments: 1 mol L−1 HCl and CO2-saturated formation water

Developing a sustainable and environmentally friendly inhibitor remains an essential and challenging goal for corrosion control. Here, different extracts from the same biomass (Juçara - Euterpe edulis) were applied as a new inhibitor for mild steel in different corrosive medium: 1 mol L−1 HCl (pH 0) and simulated CO2-saturated formation water (pH 5). Depending on the extraction process, the anticorrosive capacity of extracts may increase, a fact verified in gravimetric tests, reaching 94.4% maximum inhibition efficiency for the acidic medium (1000 mg L−1 of Juçara pulp in 48 h of immersion) and 86.1% inhibition efficiency for the saline medium (600 mg L−1 of Juçara pulp extract assisted by ultrasound in 24 h of immersion). Gravimetric tests, electrochemical tests, and surface and biochemical characterization analyses were carried out to better understand these extracts' performance. This work provides an interesting application of the same biomass effectively acting in different corrosive medium, depending on the extraction method.

Experimental and theoretical study of the photochemical properties and acidochromism of nonconventional 2,4,6-triarylpyridine-based materials

2,4,6-Triarylpyridines (TAPs) represent a versatile class of N-heterocycles with broad applications in many fields. This study presents an investigation on photochemical properties and acidochromism behavior of novel 2,6-bis(4-(dodecyloxy)phenyl)-4-(4-substituted-phenyl)pyridine-based derivatives (1a-1g). Photochemical study in dichloromethane (DCM) and acetone (ACT) solutions showed a small solvent effect for the TAP derivatives, except for the carbazole derivative 1a, which was characterized as the most emissive material in all conditions, but especially in DCM solution for blue emission (λEM = 406 nm, ϕf = 0.36). The presence of electron-donating groups at the 4-phenyl moiety contributes to more intense and redshifted emissions in both DCM and ACT solutions, as well as in the solid state. In aqueous ACT, while TAPs bearing EDGs such as 1a presented more intense emissions depending on the water fraction, an opposite effect was verified for fluorinated derivative 1f. The acidochromism of selected TAPs 1a and 1f (fluorinated derivative) in aqueous acetone was characterized by the decreasing of the emission intensity at 436 nm and 388 nm, respectively, in the presence of aqueous HCl for both TAPs, however, the protonated 1f showed strong emission in higher wavelength (λEM = 476 nm) in acidic medium. A 1H NMR study allowed a better understanding of the structural features associated to the acidochromism. The photochemical and acidochromism results obtained for the TAP derivatives are strongly supported by computational results, and particularly noteworthy is the favoring of the resonance effect as consequence of the decreasing in the torsion angle between the 4-alkoxyaryl substituents and the pyridine core after protonation of 1f. The emissive properties and acidochromism capacity of 1a and 1f allowed the potential application of TAP-adsorbed paper strips as disposable sensors for qualitative detection of gaseous HCl.

Fast and Selective Main-Chain Scission of Vinyl Polymers Using the Domino Reaction in the Alternating Sequence for Transesterification.

This communication reports on vinyl polymers capable of selective and fast main-chain scission (MCS). The trick is the domino reaction in an alternating sequence of methyl 2-(trimethylsiloxymethyl)acrylate and 5,6-benzo-2-methylene-1,3-dioxepane, a cyclic ketene acetal for radical ring-opening polymerization. Removal of the trimethylsilyl group using Bu4N+·F- readily led to MCS via irreversible transesterification of the ester backbone, affording a five-membered lactone fragment. The molar mass decreased drastically within 5 min, and no side reactions were observed. Control experiments suggest that the formation of a five-membered ring via a domino reaction is critical for fast and selective MCS. The terpolymers with methyl methacrylate and styrene also exhibited a large decrease in molar mass within 5 min. In addition, MCS was also observed for the heterogeneous reaction system in acidic aqueous media; treatment of the binary copolymer in a 50 wt % acetic acid solution resulted in a significant decrease in molar mass after 30 min. These results suggest efficient construction of degradable sites using a binary monomer system corresponding to the pendant trigger and ester backbone. Because this molecular design using a binary monomer system provides selective and fast MCS for terpolymers containing other vinyl monomers, it can provide various degradable vinyl polymers.

Deciphering the Atomic-Scale Degradation of Carbon-Supported Platinum–Yttrium Nanoalloys during the Oxygen Reduction Reaction in Acidic Medium

Deciphering the Atomic-Scale Degradation of Carbon-Supported Platinum–Yttrium Nanoalloys during the Oxygen Reduction Reaction in Acidic Medium

Helmet-Roled Molecules Carrying Double Metronidazole Frameworks and Phenyl Ring for Strengthening Adsorption and Anticorrosion on Mild Steel.

This study prepared new helmet-roled molecules (HMs) carrying metronidazole frameworks and a phenyl ring for strengthening adsorption and anticorrosion on mild steel. The adsorption of the HMs on the copper surface was understood by material simulation computation. Furthermore, the surface analysis experiments suggest that the studied molecules could be adsorbed to a mild steel surface through the chemical coordination bonding. The remarkable corrosion resistance of the HMs for mild steel in HCl was surveyed by potentiodynamic polarization and electrochemical impedance spectroscopy at 298 K. The HMs including two metronidazole skeletons displayed the stronger corrosion inhibition effect on mild steel than the HM1 bearing one single metronidazole part (the corrosion inhibition efficiency, HM3, 98.03%, HM2, 95.14%, HM1, 88.72%). The results presented in this study provided an efficient strategy to develop new clinical medicine-based corrosion inhibitors for metal in acid medium through molecular preconstruction.

Long‐Durability, Surfactant‐Free, and Bifunctional Ir‐Doped Pt3Co/MWCNTs Electrocatalysts towards ORR and OER in Acidic Media

AbstractDeveloping cost‐effective, high‐performance, and durable electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is pivotal for advancing hydrogen energy conversion and storage technologies. Simultaneously, establishing scalable methods for their production is essential for the widespread adoption of these renewable energy solutions. In this study, we present a successful large‐scale synthesis of surfactant‐free iridium‐doped Pt−cobalt nanoparticles supported on multiwalled carbon nanotubes (Ir−Pt3Co/MWCNTs). This composite demonstrates significantly enhanced ORR and OER activity compared to commercial Pt/C and IrO2 in acidic environments. The Ir−Pt3Co/MWCNTs catalyst composite exhibits a low overpotential of 357 mV at 10 mA cm−2 and a remarkable mass activity of 0.594 A/mgPt. Investigating the influence of Ir doping content on ORR and OER, we found that Pt3Co0.6Ir0.4/MWCNTs showcased the most superior activity in both reactions. We present a reproducible protocol for the synthesis of surfactant‐free Ir−Pt3Co nanoparticles supported on MWCNTs, yielding a bifunctional catalyst capable of efficiently catalyzing both ORR and OER with outstanding efficiency and stability in acidic media. Detailed X‐ray photoelectron spectroscopy (XPS) analysis elucidates the electron transfer between atoms, optimizing the electronic structure and adjusting the position of the d‐band. This optimization enhances the electrocatalytic activity and structural stability of the catalysts, contributing to their superior performance in ORR and OER.

Oxygen Functional Groups Regulate Cobalt‐Porphyrin Molecular Electrocatalyst for Acidic H2O2 Electrosynthesis at Industrial‐Level Current

AbstractElectrosynthesis of hydrogen peroxide (H2O2) based on proton exchange membrane (PEM) reactor represents a promising approach to industrial‐level H2O2 production, while it is hampered by the lack of high‐efficiency electrocatalysts in acidic medium. Herein, we present a strategy for the specific oxygen functional group (OFG) regulation to promote the H2O2 selectivity up to 92 % in acid on cobalt‐porphyrin molecular assembled with reduced graphene oxide. In situ X‐ray adsorption spectroscopy, in situ Raman spectroscopy and Kelvin probe force microscopy combined with theoretical calculation unravel that different OFGs exert distinctive regulation effects on the electronic structure of Co center through either remote (carboxyl and epoxy) or vicinal (hydroxyl) interaction manners, thus leading to the opposite influences on the promotion in 2e− ORR selectivity. As a consequence, the PEM electrolyzer integrated with the optimized catalyst can continuously and stably produce the high‐concentration of ca. 7 wt % pure H2O2 aqueous solution at 400 mA cm−2 over 200 h with a cell voltage as low as ca. 2.1 V, suggesting the application potential in industrial‐scale H2O2 electrosynthesis.

Multi-Component and Nanoporous Design toward RuO2-Based Electrocatalyst with Enhanced Performance for Acidic Water Splitting.

Developing electrocatalysts with excellent activity and stability for water splitting in acidic media remains a formidable challenge due to the sluggish kinetics and severe dissolution. As a solution, a multi-component doped RuO2 prepared through a process of dealloying-annealing is presented. The resulting multi-doped RuO2 possesses a nanoporous structure, ensuring a high utilization efficiency of Ru. Furthermore, the dopants can regulate the electronic structure, causing electron aggregation around unsaturated Ru sites, which mitigates Ru dissolution and significantly enhances the catalytic stability/activity. The representative catalyst (FeCoNiCrTi-RuO2) shows an overpotential of 167 mV at 10 mAcm-2 for oxygen evolution reaction (OER) in 0.5 m H2SO4 solution with a Tafel slope of 53.1mVdec-1, which is among the highest performance reported. Moreover, it remains stable for over 200 h at a current density of 10mAcm-2. This work presents a promising approach for improving RuO2-based electrocatalysts, offering a crucial advancement for electrochemical water splitting.

Efficient removal of Methylene blue dye from aqueous medium utilizing eco-friendly chitosan adsorbents

ABSTARCT Dyes released through various industrial operations are a major threat to the environment. The recent study introduced an eco-friendly adsorbent based on the grafting of phenolic acids (caffeic and/or gallic acids) on chitosan to reduce the hazardous impact of color effluent pollution. The morphology and structure of synthesized adsorbents were confirmed by physical and chemical tools such as TGA, FTIR, SEM, EDX, point of zero charge, water regain, and resistance of adsorbents to dissociation in acidic media. The synthesized adsorbents’ removal efficiency toward MB dye, a model cationic organic pollutant, from aqueous medium was evaluated. The factors impacting dye adsorption were investigated, including pH, dye initial concentration, and temperature. The response surface methodology (RSM) was used to confirm the interaction effects of the process variables and optimize the ideal conditions of adsorption. The maximum adsorption capacity was 257.0 and 391.8 mg/g for AI and AII, respectively, at initial MB concentration of 550 ± 1 mg/L, pH 8, and 21 ± 1 °C. MB adsorption is an exothermic chemosorption process that takes place via electrostatic attraction in an alkaline medium. Both AI and AII demonstrated significant reuse ability when eluted with a 0.5 M HCl solution.

Silica-Reinforced AMP-Calcium Alginate Beads for Efficient and Selective Removal of Cesium from a Strong Acidic Medium.

Due to the significant selectivity for Cs+, ammonium molybdophosphate (AMP) possesses potential to uptake radiocesium from high-level liquid waste (HLLW), whereas its micro-crystalline structure and fine powder morphology limit its industrial application. Although the granulation method with alginate is prospective for the preparation of an AMP exchanger, the mechanical strength of obtained beads may be insufficient for application. In this context, we prepared silica-reinforced AMP-calcium alginate (ACS) beads and evaluated their performance for Cs+ removal from strong acidic solutions. It was found that the addition of silica in the fabrication significantly improved the mechanical strength of the beads in comparison to those without silica. Notably, the beads with an AMP/silica mass ratio of 1.0 exhibited an exceptional mechanical strength, surpassing that of ACS beads composed of other components. The batch experiment results indicated that the Cs+ adsorption follows a non-linear pseudo-second-order rate equation. The distribution coefficient of Cs+ was high even in extreme acidic conditions (∼1.6 × 102 mL/g in 8.0 mol/L HNO3 solution). The Cs+ adsorption can be well fitted with the Langmuir model, and the estimated maximum exchange capacity in 3.0 mol/L HNO3 could reach 23.9 mg/g. More importantly, ACS beads showed excellent selectivity toward Cs+ uptake over eight co-existing metal ions in simulated HLLW, with separation factor values all above 145. The column experiment exhibited that the beads can serve as the stationary phase in columns to effectively remove Cs+. The findings of this study are significant as they provide insights into the development of efficient materials for radiocesium removal from high-level liquid waste. The results demonstrate the potential of silica-reinforced ACS beads for Cs+ adsorption, with promising applications in industrial settings.

Modification of Silica with Sucrose and Ammonium Fluoride Agents: A Facile Route to Prepare Supports of Iridium Catalysts for Hydrogenation Reaction.

Mesoporous silica materials were synthesized using inexpensive and environmentally friendly sucrose as a porogeneous agent. It was found that the presence of sucrose and the products of its chemical transformation during synthesis (e.g., furfural polymer) significantly affected the structure of the obtained porous silica. The influence of synthesis conditions (pH, temperature, time) on the textural properties of the final materials was determined. Samples obtained in an acidic medium, at pH = 1, and treated at room temperature, yielded products with a large surface area and a narrow pore size distribution in the range of 2-5 nm, while the synthesis at pH = 8 allowed for the formation of mesoporous systems with pores in the range of 14-20 nm. To generate acidity, the silicas were modified with an ammonium fluoride solution and then used as supports for iridium catalysts in a hydrogenation reaction, with toluene as a model hydrocarbon. The influence of parameters such as specific surface area, support acidity, and iridium dispersion on catalytic activity was determined. It was shown that modification with sucrose improved the porous structure, and NH4F modification generated acidity. These parameters favored better reducibility and dispersion of the active phase, resulting in higher activity of the catalysts in the studied hydrogenation reaction.

Biogenic corrosion inhibition through Bacillus coagulans on mild steel in mild acidic medium

In the present study, the corrosion inhibition properties of Bacillus coagulans against mild steel (MS) were studied employing electrochemical procedures to monitor the real-time corrosion rate, mechanism, development of efficient mitigation strategies, and material protection. Results of the study revealed that under acidic environments B. coagulans formed a protective biofilm on MS surface and caused marked reduction in corrosion and other forms of mutilation. Characterization and electrochemical procedures were performed to investigate the inhibitory effects of B. coagulans at different pH and at different temperatures on the corrosion rate and, to determine the mechanism of corrosion prevention. The film developed on surface of the MS by B. coagulans, was crack free, compact, and lipophilic in nature and was composed of amyloid fibers, carboxylic acid, and proteins that make electrochemical reactions that, accruing on the metal–solution interface difficult and substantial reduction in corrosion rates observed. The film adhered to the surface of metal substrates shows fitting with diverse adsorption isotherm indications, with physical adsorption being the predominant pattern observed in most cases. This suggests that the interaction between the biofilm and metal surfaces is primarily governed by physical forces. To conclude, B. coagulans exhibits protective action on MS against corrosion.

PH-sensitive polymeric micelles enhance the co-delivery of doxorubicin and docetaxel: an emerging modality for treating breast cancer

BackgroundDesigning and preparing a co-delivery system based on polymeric micelles have attracted in recent years. Co-delivery of anti-cancer agents within pH-sensitive polymeric micelles could provide superior advantages over the co-administration of free drugs, since it enables simultaneous delivery of drugs to reach an optimum synergistic dose right to the tumor.MethodsDOX was conjugated to the polymer through a hydrazine linker by Schiff’s base reaction. Then, DTX was encapsulated into the core of the polymer to the resulting DOX-Hyd-PM/DTX micelle with optimum molar ratios of 1:1 and 1:5 (DOX/DTX).ResultsThe final formulations showed the desired particle size and increased release of DOX and DTX in acidic media (pH 5.5). The cytotoxicity assay of DOX-Hyd-PM/DTX indicated the highest synergistic effect on both 4T1 and TUBO cell lines over other formulations. Interestingly, in accordance with in vitro results, DOX-Hyd-PM/DTX revealed a promising anti-tumor activity in mice-bearing 4T1 breast cancer tumor with higher tumor accumulation of DOX and DTX after 24 h compared to free drugs combination.ConclusionsThese findings point to the potential use of such smart nanodrug delivery systems in cancer treatment, where the synergistic effect of both drugs may be used to enhance therapeutic response.Graphical

Design and evaluation of a polyaniline-Azadirachta indica composite for efficient dye removal: Insights from experimental and theoretical simulations

In this study, a novel composite of polyaniline and Azadirachta indica sawdust (PAIS) was synthesized to explore its potential in the adsorptive removal of methylene blue (MB) and crystal violet (CV) dyes from aqueous solution. PAIS was characterized using various instrumental techniques, including FTIR, SEM/EDXS, XRD, TEM/SAED, BET, and TGA-DTG/DTA analyses. Batch adsorption tests revealed that pH, medium temperature, initial adsorbate concentration, adsorbent dose, and contact duration significantly influence adsorption efficiency. Adsorption equilibrium was reached at 30 min for MB and 90 min for CV in an acidic medium (up to pH 7), with minimal changes observed beyond these times. The Langmuir isotherm provided the best validation, with a maximum monolayer adsorption capacity of 454.54 mg/g for MB and 370.37 mg/g for CV, showcasing superior performance compared to most reported materials. The adsorption process adhered to a pseudo-second-order approach for both dyes, with a high coefficient of determination value. The adsorption of MB and CV by this innovative adsorbent was spontaneous, endothermic, and accompanied by entropy enhancement. The adsorbent loaded with dyes was subjected to different desorbing agents (HCl, NaOH, NaCl, CH3COOH, and H2O), and HCl was the most effective. Computational studies using Density Functional Theory supported the experimental results, confirming the higher efficiency of PAIS for MB removal over CV. It is submitted that PAIS uniquely exhibits highly adaptable, recyclable, and potent low-cost adsorbent properties for eliminating both dyes from aqueous systems, representing a significant advancement in the field of dye removal.

Ampere-level CO2 electroreduction with single-pass conversion exceeding 85% in acid over silver penetration electrodes

Synthesis of valuable chemicals from CO2 electroreduction in acidic media is highly desirable to overcome carbonation. However, suppressing the hydrogen evolution reaction in such proton-rich environments remains a considerable challenge. The current study demonstrates the use of a hollow fiber silver penetration electrode with hierarchical micro/nanostructures to enable CO2 reduction to CO in strong acids via balanced coordination of CO2 and K+/H+ supplies. Correspondingly, a CO faradaic efficiency of 95% is achieved at a partial current density as high as 4.3 A/cm2 in a pH = 1 solution of H2SO4 and KCl, sustaining 200 h of continuous electrolysis at a current density of 2 A/cm2 with over 85% single-pass conversion of CO2. The experimental results and density functional theory calculations suggest that the controllable CO2 feeding induced by the hollow fiber penetration configuration primarily coordinate the CO2/H+ balance on Ag active sites in strong acids, favoring CO2 activation and key intermediate *COOH formation, resulting in enhanced CO formation.

Enhanced antimicrobial activity of photocatalytic titanium oxide upon formation of composites with polyaniline via an eco-friendly and facile microwave synthesis approach

This study proposes inexpensive antimicrobial polyaniline-titanium oxide (PANI-TiO2) samples prepared through eco-friendly enhanced microwave (MW) synthesis with 93 W applied over 10 min in aqueous 1.25 M hydrochloric acid media (HCl) using potassium iodate (KIO3) as oxidising agent, an approach suitable for industrial scale up production of PANI polymers at room temperature. The PANI-TiO2 samples are produced in the presence of 5–20 wt% of TiO2 in the initial reaction mixture along with aniline monomer by both the enhanced MW method and a classical chemical synthesis (CS) method at room temperature. The nanocomposites showed lower conductivity than pure PANI, slightly higher conductivity was observed in the MW prepared PANI-TiO2 in comparison to CS prepared PANI-TiO2. This result can be correlated with the observation that the optical absorbance of MW PANI-TiO2 samples were notable higher than for CS PANI-TiO2, which may be due to the presence of a greater amount of polarons present in the samples prepared by the enhanced MW method. MW PANI-TiO2 samples were equally active against both Gram-negative E. coli and Gram-positive S. aureus bacteria, in contrast to the CS PANI-TiO2 samples, which could be due to presence of short-chain fragments in the CS samples as confirmed by Fourier-transform infrared (FTIR) spectroscopy. The incorporation of PANI particles in TiO2 showed enhanced antimicrobial activity compared to pure TiO2, with greater antifungal activity. Our study indicates that a facile, low-cost, and green enhanced MW method can be used for preparation of the advanced antimicrobial PANI-TiO2 nanocomposites for biomedical applications.

High-output tuber crops-derived porous spherical carbons: Curved tip electric field-dependent activity for oxygen reduction catalysis

Metal-free nanocarbons with highly editable compositions and well-defined morphologies, and adjustable coordination environments have been considered as promising and inexpensive electrode materials that can be used in the fields of fuel cells and metal-air batteries. Herein, the typical micromorphology of high-output tuber crops potato was examined for the first time by cryo-electron microscopy, and nitrogen-doped spherical carbons with highly curved carbon layers were prepared from potato and sweet potato by hydrothermal and ammonia-activated treatments. The potato-derived carbon (PC) and sweet potato-derived carbon (SPC) with enriched nitrogen dopants on native curved carbon layers exhibit favorable oxygen reduction reaction (ORR) activities in both acidic and alkaline media. The half-wave potential of the curved PC is 60 mV higher than that of commercial Pt/C (20 wt% Pt) in 0.1 M KOH. Impressively, the zinc-air battery using the curved PC displays excellent stability and achieves a peak power density of 116 mW cm−2, surpassing the performance of Pt/C (108 mW m−2). Finite element method (FEM) simulations and molecular dynamics (MD) calculations reveal that the curved carbon surface-enhanced tip electric field on the spherical structure, could further induce charge transfer and accelerate the ORR process. This work elucidates the origin of the catalytic activity of spherically structured metal-free carbons with N-doping, providing meaningful insights into the development of low-cost and highly active catalysts and advancing the field of sustainable energy.

Design of silver-zinc-nickel spinel-ferrite mesoporous silica as a powerful and simply separable adsorbent for some textile dye removal

Silver-zinc-nickel spinel ferrite was prepared by the co-precipitation procedure with the precise composition Ag0.1Zn0.4Ni0.5Fe2O4 for bolstering pollutant removal effectiveness while upholding magnetic properties and then coated with a mesoporous silica layer. The surface characteristics and composition of Ag0.1Zn0.4Ni0.5Fe2O4@mSiO2 were confirmed using EDX, FT-IR, VSM, XRD, TEM, SEM, and BET methods. The surface modification of Ag-Zn-Ni ferrite with a silica layer improves the texture properties, where the specific surface area and average pore size of the spinel ferrite rose to 180 m2/g and 3.15 nm, respectively. The prepared spinel ferrite@mSiO2 has been utilized as an efficient adsorbent for eliminating methyl green (MG) and indigo carmine (IC) as models of cationic and anionic dyes from wastewater, respectively. Studying pH, Pzc, adsorbent dosage, dye concentration, and temperature showed that efficient removal of MG was carried out in alkaline media (pH = 12), while the acid medium (pH = 2) was effective for IC removal. Langmuir isotherm and pseudo-second-order kinetics were found to be good fits for the adsorption data. Both dyes were adsorbed in a spontaneous, endothermic process. A possible mechanism for dye removal has been proposed. The adsorbent was effectively recovered and reused.