Ultrahigh Specific Surface Area Research Articles

Preparation of nano Cu-Mo2C interface supported on ordered mesoporous biochar of ultrahigh surface area for reverse water gas shift reaction

High conversion rate and selectivity are challenges for CO2 utilization through catalytic reverse water gas shift (RWGS) reaction. Herein, a novel mesoporous biochar (MB) supported Cu-Mo2C nano-interface was prepared by consecutive physical activation of coconut shells followed by carbothermal hydrogen reduction of bimetal. As compared with traditional carbon materials, this MB exhibited ultra-high specific surface area (2693 m2 g–1) and mesopore volume of mesopore (0.81 cm3 g–1) with a narrow distribution (2–5 nm), responsible for the high dispersion of binary Cu-Mo2C sites, CO2 adsorption and mass transfer in the reaction system. Moderate carbothermal reduction led to the sufficient reduction of Mo ion with carbon matrix of MB and dispersive growth of nano Cu-Mo2C binary sites (~ 6.1 nm) on the surface of MB. Cu+ species were formed from Cu0 via electron transfer and showed high dispersion with simultaneous boosted bimetal loading due to the strong interaction between nano Mo2C and Cu. These were advantageous to the intrinsic activity and stability of the Cu-Mo2C binary sites and their accessibility to the reactant molecules. Under the RWGS reaction conditions of 500 °C, atmospheric pressure, and 300,000 ml/g/h gas hour space velocity, the CO2 conversion rate over Cu-Mo2C/MB reached 27.74 × 10–5 molCO2/gcat/s at very low H2 partial pressure, which was more than twice that over traditional carbon supported Cu-Mo2C catalysts. In addition, this catalyst exhibited 99.08% CO selectivity and high stability for more than 50 h without a decrease in activity and selectivity. This study offers a new development strategy and a promising candidate for industrial RWGS.Graphical

Sustainable and Biosafe Approach to Control Potato Late Blight Using Mesoporous Silica Nanoparticles.

Phytophthora infestans-induced potato late blight is considered the "cancer of the potato crop." In this work, mesoporous silica nanoparticles (MSNs) with ultrahigh specific surface area (786.28 m2/g) were synthesized, which significantly inhibited P. infestans compared with some commercial fungicides. Moreover, MSNs inhibited the growth and reproductive of P. infestans processes, including germination, sporangia infection, and zoospore release. MSNs targeted key biological pathways and induced a stress response in the P. infestans, leading to reactive oxygen species (•O2-, •OH, and 1O2) production and structural damage of sporangia. Pot experiments showed that MSNs are translocated from leaves to roots of potato plants, enhancing physiological and biochemical processes, alleviating drought stress, improving resistance to pathogens, and exhibiting soil microbe-friendly. This study systematically reveals the mechanism of MSNs to weaken the reproduction process of P. infestans and confirm the safety and feasibility of MSNs as a green and sustainable fungicide.

Supercapacitor electrodes derived from ultra-high surface area activated carbon spheres synthesized by fluidized activation

This study thoroughly investigated the effects of activation conditions on pore structure development using response surface methodology with a central composite design. The activated carbon sphere (ACS) derived from phenolic formaldehyde resins by carbonization and fluidized activation was examined and characterized. The pore size distribution of ACS samples was all in the microporous and mesoporous scales. ACS with an ultra-high specific surface area of 3142 m2 g−1 and total pore volume of 1.513 cm3 g−1 was successfully obtained at 900 °C for 4 h. Electric double-layer capacitor (EDLC) electrodes derived from ACS with different activation conditions were examined by using cyclic voltammetry and galvanostatic charge/discharge to comprehend the influence of surface area, pore volumes, and the amount of binder on the electrochemical performance. The optimal EDLC electrode was obtained using ACS with the largest specific surface area and pore volume with 5 wt% of binder addition. The specific capacitance was 143.7 F g−1 in a 1 M H2SO4 solution. The cyclical stability of the carbon electrode was also examined under 5000 cycles, and the charge/discharge efficiency remained nearly 100 % without deterioration. This study provides insights into fabricating ultra-high surface area ACS and their potential application as supercapacitors.

Wood derived conductive aerogel with ultrahigh specific surface area and exceptional mechanical flexibility for pressure sensing

Conductive nanocellulose aerogels possess durability and sensitivity by using as piezoresistive sensors. Those aerogels are mostly prepared via a “bottom-up” strategy by using nanocellulose or dissolved and regenerated cellulose as raw materials. However, there is a pressing need to further enhance their sustainability and economic viability. To alleviate these issues, cellulose aerogel can alternatively be made via a “top-down” technique that entails the direct removal of contaminants from naturally porous biomass. Herein, conductive aerogels with exceptional mechanical flexibility and ultrahigh specific surface area were created. Delignified wood was partially dissolved and regenerated to created nanocellulose fibrils with spider web structure inside the pores of wood. After modification with silane coupling agent and Carbon Nanotubes (CNTs), flexible conductive wood aerogel (C-WA) were obtained. The specific surface area of C-WA was as high as 333.82 m2/g, which was 45 times of that of wood. C-WA could maintain its good resilience even after 1000 cycles, showing high compression resilience and excellent fatigue resistance (stress retention rate was 87.22 %, height retention rate was 99.5 %). The utilization of C-WA as a pressure sensor demonstrated remarkable attributes, including ultra-fast response and stability within the designated range. Furthermore, it exhibited exceptional sensing performance even after enduring 2000 stable cycles. The system is capable of real-time, accurate, and efficient detection of human motion signals, showcasing immense potential for future applications in wearable electronic products.

Preparation of Hierarchical Porous Monoliths With High Surface Areas by a Solvent Knitting Strategy.

Hierarchical porous hypercrosslinked monoliths (PolyHIPE-HCP) with ultrahigh specific surface areas are prepared via a solvent knitting strategy. Compared to previous work, the solvent knitting strategy is carried out in a relatively low air-controlled atmosphere with gradient heating starting from low temperature while using DCM (Dichloromethane) as both a solvent and a cross-linker, allowing for a slow and controlled cross-linking process, thereby achieving a BET surface area ranging from 514 to 728m2g-1. Scanning electron microscopy (SEM) shows that the knitting process does not affect the presence of macroporous structure in the PolyHIPE. With the introduction of mesopores and micropores, these hierarchical porous monoliths exhibit significant potential for applications in gas adsorption and water treatment. Hence, a universal, simple and low-cost method to synthesize polymeric monoliths with hierarchically porous structure and higher surface area is proposed, which has fascinating prospects in industrialization.

Hierarchically Porous Structured Adsorbents with Ultrahigh Metal-Organic Framework Loading for CO2 Capture.

Metal-organic frameworks (MOFs) have emerged as promising candidates for CO2 adsorption due to their ultrahigh-specific surface area and highly tunable pore-surface properties. However, their large-scale application is hindered by processing issues associated with their microcrystalline powder nature, such as dustiness, pressure drop, and poor mass transfer within packed beds. To address these challenges, shaping/structuring micron-sized polycrystalline MOF powders into millimeter-sized structured forms while preserving porosity and functionality represents an effective yet challenging approach. In this study, a facile and versatile strategy was employed to integrate moisture-stable and scalable microcrystalline MOFs (UiO-66 and ZIF-8) into a poly(acrylonitrile) matrix to fabricate readily processable, millimeter-sized hierarchically porous structured adsorbents with ultrahigh MOF loadings (∼90 wt %) for direct industrial carbon capture applications. These structured composite beads retained the physicochemical properties and separation performance of the pristine MOF crystal particles. Structured UiO-66 and ZIF-8 exhibited high specific surface areas of 1130 m2 g-1 and 1431 m2 g-1, respectively. The structured UiO-66 achieved a CO2 adsorption capacity of 2.0 mmol g-1 at 1 bar and a dynamic CO2/N2 selectivity of 17 for a CO2/N2 gas mixture with a 15/85 volume ratio at 25 °C. Furthermore, the structured adsorbents exhibited excellent cyclability in static and dynamic CO2 adsorption studies, making them promising candidates for practical application.

Highly porous carbon with rich inherent groups for ultrahigh adsorption of organic dyes from wastewater

Activated carbon from renewable biomass or its waste to purify various dyeing wastewater from textile industry is highly desired. In this work, porous activated carbon was prepared by using silk waste as precursor via a simple one-step carbonization process. The obtained SWC-1-800 had ultrahigh adsorption for anionic dye AR73 and cationic dye MB owing to its ultrahigh specific surface area (2774 m2 g−1) and rich functional groups. SWC-1-800 had an increased adsorption capacity reaching 1310 and 928 mg g−1 for AR73 and MB respectively as the initial concentration up to 1000 mg L−1. Moreover, the adsorption capacity was stable under a wide range of Na+ and SDS concentration. By adjusting the temperature and pH value, the maximum adsorption capacity reached 1337 and 1000 mg g−1 for AR73 and MB respectively, keeping the removal rate of AR73 and MB more than 80 % after 5 adsorption cycles. Besides, SWC-1-800 demonstrated quite good adsorption ability for many other kinds of dyes, which adsorption capacity as high as 1998 mg g−1 (Rh B). The adsorption mechanism was further proposed according to the structural characteristics, inherent functional groups and adsorption properties. Using silk waste-derived carbon to effectively absorb the harmful dyes in the wastewater shows dual value for cleaner production via a “waste-waste to clean products” model, which has great application potential in dyeing wastewater purification.

Vacancies engineering in ultrathin porous g-C3N4 tubes for enhanced photocatalytic PMS activation for imidacloprid degradation

Precise morphology and vacancy engineering is a promising strategy to enhance the degradation performance of refractory contaminants in photocatalysis coupling peroxymonosulfate activation (PC-PMS) systems. In this context, we developed ultrathin porous g-C3N4 tubes with three-coordinated nitrogen (Nb) vacancies between the heptazine units through hydrogen intercalated exfoliation and selective nitrogen removal at high temperatures. The ultrathin porous tubular architecture provides an ultrahigh-specific surface area with abundant exposed active sites, ensures effective mass transfer, and shortens the diffusion distance of photogenerated carriers. The Nb vacancies act as unsaturated sites, inhibiting the photogenerated carrier’s recombination and facilitating the adsorption/activation of O2 and its conversion to ∙O2– via photogenerated electrons. Then, the PMS is subsequently oxidated by photogenerated holes selectively producing 1O2. Together, these continuously released free radicals unlock the complete degradation of imidacloprid within 20 min in the PC-PMS system, with a degradation rate about 350 % higher than conventional g-C3N4 tubes and 10-fold that of pristine g-C3N4. This study provides a novel insight into the efficient utilization of photogenerated electron-hole pairs conversion to ∙O2– and 1O2 for the removal of pesticide contaminants through the rational design of photocatalysts in the PC-PMS system.

Controllable synthesis of TiO2/graphene composites for human voice recognition in strain sensor.

Low-dimensional materials have demonstrated strong potential for use in diverse flexible strain sensors for wearable electronic device applications. However, the limited contact area in the sensing layer, caused by the low specific surface area of typical nanomaterials, hinders the pursuit of high-performance strain-sensor applications. Herein, we report an efficient method for synthesizing TiO2-based nanocomposite materials by directly using industrial raw materials with ultrahigh specific surface areas that can be used for strain sensors. A kinetic study of the self-seeded thermal hydrolysis sulfate process was conducted for the controllable synthesis of pure TiO2 and related TiO2/graphene composites. The hydrolysis readily modified the crystal form and morphology of the prepared TiO2 nanoparticles, and the prepared composite samples possessed a uniform nanoporous structure. Experiments demonstrated that the TiO2/graphene composite can be used in strain sensors with a maximum Gauge factor of 252. In addition, the TiO2/graphene composite-based strain sensor showed high stability by continuously operating over 1,000 loading cycles and aging tests over three months. It also shows that the fabricated strain sensors have the potential for human voice recognition by characterizing letters, words, and musical tones.

Robust Multifunctional Ultrathin 2 Nanometer Organic Nanofibers.

Ultrathin organic nanofibers (UTONFs) represent an emerging class of nanomaterials as they carry a set of favorable attributes, including ultrahigh specific surface area, lightweight, and mechanical flexibility, over inorganic counterparts, for use in biomedicine and nanotechnology. However, precise synthesis of uniform UTONFs (diameter ≤ 2 nm) with tailored functionalities remained challenging. Herein, we report robust multifunctional UTONFs using hydrophobic interaction-driven self-assembly of amphiphilic alternating peptoids containing hydrophobic photoresponsive azobenzene and hydrophilic hydroxyl moieties periodically arranged along the peptoid backbone. Notably, the as-crafted UTONFs are approximately 2 nm in diameter and tens of micrometers in length (an aspect ratio, AR, of ∼10000), exemplifying the UTONFs with the smallest diameter yielded via self-assembly. Intriguingly, UTONFs were disassembled into short-segmented nanofibers and controllably reassembled into UTONFs, resembling "step-growth polymerization". Photoisomerization of azobenzene moieties leads to reversible transformation between UTONFs and spherical micelles. Such meticulously engineered UTONFs demonstrate potential for catalysis, bioimaging, and antibacterial therapeutics. Our study highlights the significance of the rational design of amphiphiles containing alternating hydrophobic and hydrophilic moieties in constructing otherwise unattainable extremely thin UTONFs with ultrahigh AR and stimuli-responsive functionalities for energy and bionanotechnology.

In‐Plane heterostructured FeCoS@NiCo-LDH nanosheets with improved interfacial charge transfer for hybrid supercapacitors

Engineering a heterogeneous structure with distinctive morphology and nanostructure is deemed to be an efficacious tactic for realising high energy density supercapacitors (SCs). Herein, the FeCo2S4@NiCo-LDH(FeCoS@NiCo-LDH)/NF nanocomposite heterostructure is successfully constructed through a facile two-step electrodeposition method. This heterostructure merges the merits of FeCoS with high electrical conductivity and NiCo-LDH with ultra-high specific surface area, which not only can deliver sufficient electroactive central sites, but also provide shorter routes for expedited ion diffusion, even more significantly, the heterogeneous interfaces that emerge in composites can moderate their electronic structure and augment electrical conductivity. Density functional theory (DFT) calculations indicate that the heterostructured FeCoS@NiCo-LDH/NF displays preferable electrochemical activeness and enhanced adsorption ability. Thanks to the abundance of heterogeneous interfaces and synergistic effects of the various active ingredients, FeCoS/NiCo-LDH electrodes exhibit an extraordinary specific capacity of 930 C g−1 at 1 A g−1 together with remarkable cycle longevity (10.9 % capacity decay after 10,000 cycles). In addition, a hybrid FeCoS@NiCo-LDH/NF//AC exhibits a high energy density of 52.81 Wh kg−1 at the 750 W kg−1.

Recent Advances of Carbon Capture in Metal-Organic Frameworks: A Comprehensive Review.

The excessive emission of greenhouse gases, which leads to global warming and alarms the world, has triggered a global campaign for carbon neutrality. Carbon capture and sequestration (CCS) technology has aroused wide research interest as a versatile emission mitigation technology. Metal-organic frameworks (MOFs), as a new class of high-performance adsorbents, hold great potential for CO2 capture from large point sources and ambient air due to their ultra-high specific surface area as well as pore structure. In recent years, MOFs have made great progress in the field of CO2 capture and separation, and have published a number of important results, which have greatly promoted the development of MOF materials for practical carbon capture applications. This review summarizes the most recent advanced research on MOF materials for carbon capture in various application scenarios over the past six years. The strategies for enhancing CO2 selective adsorption and separation of MOFs are described in detail, along with the development of MOF-based composites. Moreover, this review also systematically summarizes the highly concerned issues of MOF materials in practical applications of carbon capture. Finally, future research on CO2 capture by MOF materials is prospected.

Highly porous carbon with selective transformation of nitrogen groups boosts the capacitive performance through boric acid template assisted strategy

To address the extensive demand for energy storage, the development of unique carbon-based supercapacitors represents a viable solution. We successfully synthesize the unique boron (B), nitrogen (N)-containing porous carbon (denoted as BNPC) from reed biomass through one-step boric acid templated carbonization method, which are used as high-performance carbon electrode for electric double-layer capacitor (EDLC). By the synergistic effects of boric acid template and N-rich melamine, a well-balanced micro‐/meso-porous structure and abundant N and oxygen (O) heteroatoms within BNPC are readily obtained, exhibiting an ultrahigh specific surface area of 2619 m2·g−1. These distinctive natures endow BNPC electrode with the excellent capacitive behaviors, affording an outstanding specific capacitance of 396.8 F·g−1 at a three-electrode (3E) system with KOH electrolyte. Density functional theory (DFT) method is utilized to further clarify the interaction mechanism between K and designed graphene with various N configurations, revealing the significant roles of Pyridinc-N and Graphitic-N. The two-electrode (2E) symmetric supercapacitor assembled by BNPC electrodes in TEABF4 electrolyte demonstrates an extremely high energy density of 51.82 Wh·kg−1 at a power density of 375 W·kg−1 and great capacitance retention of 91 % after 6000 cycles. This reed-derived highly porous carbons display superior electrochemical performance, making it the ideal candidates for large capacity supercapacitors in practice.

Electrochemical and physical adsorption properties of activated carbon with ultrahigh specific surface area using 2,9-dimethyl quinacridone (2,9-DMQA)

Electrochemical and physical adsorption properties of activated carbon with ultrahigh specific surface area using 2,9-dimethyl quinacridone (2,9-DMQA)

Laser Additive Manufacturing of Three-Dimensional Ti/TiN Nanotube Arrays with Hierarchical Pore Structures and Promoted Supercapacitor Performances.

Titanium-based composites hold great promise in versatile functional application fields, including supercapacitors. However, conventional subtractive methods for preparing complex-shaped titanium-based composites generally suffer from several significant shortcomings, including low efficiency, strictly simple geometry, low specific surface area, and poor electrochemical performance of the products. Herein, three-dimensional composites of Ti/TiN nanotube arrays with hierarchically porous structures were prepared using the additive manufacturing method of selective laser melting combined with anodic oxidation and nitridation. The resultant Ti/TiN nanotube array composites exhibit good electrical conductivity, ultrahigh specific surface areas, and outstanding supercapacitor performances featuring the unique combination of a large specific capacitance of 134.4 mF/cm2 and a high power density of 4.1 mW/cm2, which was remarkably superior to that of their counterparts. This work is anticipated to provide new insights into the facile and efficient preparation of high-performance structural and functional devices with arbitrarily complex geometries and good overall performances.

Straw-based biochar prepared from multi-step KOH activation and its structure-effect relationship of CO2 capture under atmospheric/pressurized conditions via experimental analysis and MD/DFT calculations

Porous carbon-based CO2 capture holds great promise. However, the preparation process, pore structure and oxygen/nitrogen functional groups of porous carbon on CO2 adsorption still remain unclear. Herein, we develope straw-based biochar with ultra-high specific surface area(SSA), high micropore ratio and different O/N content by modifying the two-step KOH activation procedure and confirm the KOH activation mechanism, CO2 adsorption characteristics, and the structure-effect relationship of CO2 capture. The KOH activation process is controlled by the activation temperature and is divided into five temperature zones. The pickling treatment enhanced the activation effect of biochar, with a SSA of 3567.33 m2/g and a microporous ratio of 96.05 %. The potassium-containing active components reacts with the defective carbon structure above 800 °C catalyzed by alkali and alkaline earth metals(AAEMs), but reacts with the aliphatic hydrocarbon group after pickling. H-4–9-4-m has a maximum CO2 adsorption capacity of 24.77 mmol/g (25 °C/30 bar), whereas 4–9-2-m has a maximum capacity of 3.46 (25 °C/1 bar) and 5.42 mmol/g (0 °C/1 bar) and outstanding CO2/N2 selectivity (123 at 0.02 bar). The pressurized CO2 adsorption capacity is positively correlated with total pore volume. While under atmospheric pressure, the optimal adsorption site of biochar at 25 °C is ultramicroporous(0.5 nm) and oxygen-containing functional groups, and transforms into ultramicroporous(0.7 nm) and N-5 groups at 0 °C. The simulation results show that 0.5 nm is the pore size of CO2 adsorption from monolayer to bilayer, and both oxygen/nitrogen-containing groups could increase the CO2 adsorption capacity of biochar. This study provides guidance for the preparation of excellent carbon-based CO2 adsorbents according to application scenarios.

Coal gasification fine slag derived porous carbon-silicon composite as an ultra-high capacity adsorbent for Rhodamine B removal

The extensive release of industrial solid wastes and organic dyes has led to severe environmental pollution, underscoring the urgent need to recycle these solid wastes and to remove the dyes. Herein, a porous carbon-silicon composite (PC-SiO2) is synthesized using coal gasification fine slag (CGFS) as a precursor via an alkali (KOH) activation and an acid (HCl) etching process, and used as an adsorbent for the Rhodamine B (RhB) removal. The as-synthesized PC-SiO2 possesses an ultra-high specific surface area of 1275.63 m2/g, a large pore volume of 0.26 cm3/g, and enriched reactive functional groups (e.g., Si-OH and –COOH). Due to these features, the actual adsorption capacity and removal ratio of the PC-SiO2 for RhB were as high as 1383.72 mg/g and 92.25 %, respectively, at 298.15 K and pH = 7. Further studies indicate that the adsorption of RhB on PC-SiO2 fits both the pseudo-second-order kinetic model and the Langmuir model, with the maximum equilibrium adsorption capacity being 1388.89 mg/g as predicted by the Langmuir model. The adsorption process involves the electrostatic attraction, hydrogen bonding, π-π interaction, and pore-filling mechanism. This work not only offers a novel approach for removing organic dyes from industrial wastewater but also provides an effective strategy for producing high-value-added materials from industrial solid wastes.

Biochar with enhanced performance prepared based on “graphite-structure regulation” conjecture designed to effectively control water pollution

In this work, corn straw was used as raw material, Hummers method and activation were used to adjust the graphite structure in biochar, and preparing straw based biochar (H-BCS) with ultra-high specific surface area (3441.80 m2/g), highly total pore volume (1.9859 cm3/g), and further enhanced physicochemical properties. Compared with untreated straw biochar (BCS), the specific surface area and total pore volume of H-BCS were increased by 47.24 % and 55.85 %, respectively. H-BCS showed good removal ability in subsequent experiments by using chloramphenicol (CP), hexavalent chromium (Cr6+), and crystal violet (CV) as adsorption models. In addition, the adsorption capacities of H-BCS (CP: 1396.30 mg/g, Cr6+: 218.40 mg/g, and CV: 1246.24 mg/g) are not only higher than most adsorbents, even after undergoing 5 cycles of regeneration, its adsorption capacity remains above 80 %, indicating significant potential for practical applications. In addition, we also speculated and analyzed the conjecture about the “graphite-structure regulation” during the preparation process, and finally discussed the possible mechanism during the adsorption processes. We hope this work could provide a new strategy to solve the restriction of biochar performance by further exploring the regulation of graphite structure in carbon materials.

Shuttle-free zinc–iodine batteries enabled by a cobalt single atom anchored on N-doped porous carbon host with ultra-high specific surface area

Aqueous zinc‑iodine batteries are favorable solutions for grid-level energy storage owing to their cost-effective components and intrinsic safety. Nevertheless, the sluggish conversion kinetics and polyiodide shuttle effect have significantly hindered their practical applications. Herein, a Co single atom anchored on N-doped porous carbon nanosheets (Co-SAs@NPC) was produced through an efficient molten-salt engaged pyrolysis process and further utilized as the iodine host for aqueous zinc-iodine batteries. The large specific surface area (1741 m2 g−1) combined with abundant heteroatom-containing functional groups can afford a tight physical and chemical confinement towards iodine species. Meanwhile, the presence of Co single atoms exhibits high electrocatalytic activity towards I2 reduction reactions. According to the experimental results and DFT theoretical calculations, the resulting Co-SAs@NPC can simultaneously offer generous electrochemical active sites and electrocatalytic activity, which displays a high adsorption ability towards iodide species and boost the reversible redox reactions between iodine and iodides. Consequently, the as-assembled zinc-iodine batteries with Co-SAs@NPC/I2 cathodes can deliver a high specific capacity (295 mA h g−1 at 0.3 A g−1), good rate performance (199 mAh g−1 at 20 A g−1), and long cyclic stability over 10,000 cycles. Additionally, the absence of polyiodide shuttle was analyzed by a series of ex-situ spectrum analyses.

Effects of Fe(II) bio-oxidation rate and alkali control on schwertmannite microstructure and adsorption of oxyanions: Characteristics, performance and mechanism

Schwertmannite has attracted increasing interest for its excellent sorption of oxyanions such as AsO43−, CrO42−, and Sb(OH)6−. Controlling biomineralization by adjusting the Fe(II) oxidation rate and implementing alkali control can enhance the yield and adsorption performance of schwertmannite. However, the adsorption improvement mechanism is still unclear. The morphology, crystallinity, specific surface area (SSA) and oxyanion adsorption of schwertmannite synthesized with alkali control of solution pH and different Fe(II) oxidation rates were analyzed in this study. The differences in the adsorption mechanisms of As(V), Cr(VI) and Sb(V) on schwertmannite obtained under different synthesis conditions were also studied. Reducing the Fe(II) oxidation rate or maintaining the solution pH through alkali control significantly increased the SSA of schwertmannite and the proportion of outer-sphere sulfate. Alkali-controlled schwertmannite (Sch-C) exhibited superior As(V) and Sb(V) adsorption performance and slightly greater Cr(VI) adsorption than non-alkali-controlled schwertmannite. The As(V) and Sb(V) adsorption capacities of Sch-C greatly improved because the ultra-high SSA increased the surface hydroxyl content and reduced the passivation effect of amorphous precipitates on the mineral surface, allowing continuous sulfate exchange at inner mineral sites. An increased surface hydroxyl content had little effect on Cr(VI) adsorption, but an increased proportion of outer-sphere sulfate caused a slight increase in Cr(VI) adsorption. Sb(V) has a stronger hydroxyl exchange ability than As(V), but due to its octahedral structure, it exchanges only with outer-sphere sulfate on schwertmannite and hardly exchanges with inner-sphere sulfate.