Calcination Treatment Research Articles

Multi-functional hydrogen- and oxygen-capturing FeCo-N-C catalyst with improved hydrogenation of nitroarenes and ORR activity

Hydrogen energy storage and transportation are critical issues that must be addressed to ensure the development of alternatives to fossil fuel energy in the future. Herein, the poly(Schiff base) strategy is used to explore the carbon substrate, which is enclosed with binary metal Fe and Co as precursors. After the calcination and acid treatment steps, one of the FeCo alloy, termed FeCoNC-1000A900, was assembled with porous carbon skeleton as a shell and enclosed with FeCo alloy as a core. The FeCoNC-1000A900 exhibits outstanding H2 capture properties from NaBH4/EtOH mixtures circumstance owing to its large average particle size of 45 nm and high specific surface area of 462.07 m2/g. Notably, the FeCoNC-1000A900 acquires bi-functional catalysis efficacy, one is for chemoselectivity in the hydrogenation of nitroarene substrates and shows a high turnover frequency in 690 h−1 within the overall conversion yield. The other one is the O2 capture performance toward the oxygen reduction reaction with the excellent onset potential of 0.89 V, the half-wave potential of 0.77 V, and limiting current density of − 5.56 mA cm−2, which are comparable to those of the commercial Pt/C catalyst. In addition, the Tafel slope of 79.6 mV dec−1 is lower than those for other catalysts. Consequently, the development of the novel FeCoNC-1000A900 catalyst has two functional applications.

Rational fabrication of metal phosphide nanoparticles immobilized in electrospun carbon nanofibers for efficient pH-universal hydrogen evolution and overall water splitting

Design and preparation of bifunctional electrocatalysts with optimized structures and abundant electrocatalytic active sites are significant for hydrogen generation in electrocatalytic water splitting. Herein, we have elaborately prepared Fe-doped CoP nanoparticles encapsulated in porous electrospun carbon nanofibers for bifunctional electrocatalysis on both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The morphologies, components, and properties of the prepared electrocatalysts are influenced by the introduction of a facile air calcination treatment. Porous nanostructure as well as the full conversion of metal active sites are simultaneously achieved. Owing to the protective electrospun carbon nanofibers as well as the abundant exposed active sites, the optimized electrocatalyst exhibits excellent pH-universal HER activities with small overpotentials (99 mV, 159 mV, and 185 mV) at 10 mA cm−2 in acidic, alkaline, and neutral electrolytes, and also presents remarkable OER performance. Moreover, a water electrolyzer cell, using the optimized electrocatalyst as the electrodes, manifests both a high efficiency (1.63 V@10 mA cm−2) and robust stability. This work provides a convenient route for the controllable fabrication of transition metal-based electrocatalysts toward energy conversion.

Top-down fabrication of active interface between TiO2 and Pt nanoclusters. Part 1: Redispersion process and mechanism

Supported metal nanoclusters (NCs) are regarded as the next generation of catalyst that bridge the nanocatalyst and single-atom catalyst. However, feasible fabrication of thermally stable NCs has remained a daunting challenge. In this paper, the first part of an extended work, we report a simple route to fabricate Pt NCs in size of around 1 nm through redispersion of Pt nanoparticles (NPs) or commercial PtO2 by a calcination treatment. Combining control experiments and detailed DFT simulation, the whole redispersion process was described and evidenced to proceed via a gas-phase trapping way: Under promotion of oxygen atmosphere and high temperature, volatile oxidized Pt monomers were firstly generated and then trapped by surface defects, forming special sites that preferentially induce the growth of clusters on them. The growing clusters have both size- and temperature-dependent stability, resulting a most stable size distribution of around 1 nm when fabricated at 550 °C. This work provides a feasible top-down strategy to fabricate highly dispersed metal clusters.

Phyto-synthesis of tin oxide nanoparticles using Diospyros mollis leaves extract doped graphitic carbon nitride for photocatalytic methylene blue degradation and hydrogen peroxide production

In this study, tin oxide nanoparticles (SnO2 NPs) were combined with graphitic carbon nitride (gCN) to produce the SnO2/gCN composite for photocatalytic methylene blue (MB) degradation and H2O2 production. Specifically, SnO2 NPs were initially prepared using a biological pathway from Diospyros mollis leaves extract, followed by the incorporation on gCN via calcination treatment. Characterization of SnO2/gCN was conducted through analytical methods, including scanning electron microscopy, energy dispersive X-ray spectroscopy, field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, N2 sorption isotherm, photoluminescence spectroscopy, and ultraviolet-visible diffuse reflectance spectroscopy (UV-DRS). The optical band gap of the nanocomposite was also evaluated to be 2.44 eV using the Tauc plot and UV-DRS, which is lower than pristine gCN. The photocatalytic performance over the optimal 1.0SnO2/gCN sample was resultingly investigated, reaching over 99.76 % of MB degradation efficiency within 120 min, and 4060.78 μM/g.h of H2O2 production rate under visible light radiation. Insights into the mechanism revealed the vital participation of reactive radicals, especially •O2− and •OH, in the degradation of MB molecules, while the reusability of 1.0SnO2/gCN was also maintained after 4 succeeding photocatalytic cycles. Such findings affirm the promising applicability of the constructed SnO2/gCN material in many industries, namely the environmental remediation and cleaner production sectors.

INFLUENCE OF MODIFICATION ON PROPERTIES OF ZSM-5 ZEOLITE IN THE REACTION OF TOLUENE ALKYLATION WITH ISOPROPANOL

Bimetallic catalysts based on ZSM-5 zeolite modified with ytterbium and nickel have been prepared. The influence of the concentration of ytterbium (1.7–5.0 wt.%) and nickel (1.0–1.5 wt.%) on the acidic, textural and catalytic properties of the zeolite in the reaction of alkylation of toluene with isopropanol in the temperature range of 300–3500C was studied. It has been shown that the unmodified zeolite HZSM-5 exhibits low selectivity (54.6–58.2%) for isopropyltoluenes (3-IPT, 4-IPT, and 2-IPT) than the modified catalysts. In addition, the content of the valuable 4-IPT isomer does not exceed 44.2%. Modification of HZSM-5 with ytterbium in an amount of 5.0 wt.% leads to an increase in the selectivity for isopropyltoluenes up to 68.7%, and the selectivity for 4-IPT up to 68.8%. Additional modification of the 3%-Yb-HZSM-5 catalyst with nickel in the amount of 1.0 wt.% prevents the formation of 2-IPT and promotes an increase in the yield of 4-IPT. The modified catalysts were characterized by XPA, BET, BJH, and ammonia TPD. Modification, calcination, and successive treatment of the catalyst with air and hydrogen leads to a dispersed distribution of Yb2O3 and metallic nickel oxide nanoparticles in the outer surface and in the pores of the zeolite, which causes a decrease in the specific surface area, total pore volume, and an increase in the fraction of mesopore volume. As a result of the interaction of modifiers with acidic OH groups of the zeolite, the concentration of strong Brønsted acid sites decreases and new, stronger Lewis acid sites form. All this has a decisive effect on the selectivity of 4-IPT formation and the stability of the bimetallic catalyst. The maximum selectivity for 4-IPT on a 3% Yb 1.0% Ni/HZSM-5 bimetallic catalyst is achieved at 3300C and is 71.5% at a toluene conversion of 24.6%.

Kirkendall effect-induced uniform stress distribution stabilizes nickel-rich layered oxide cathodes

Nickel-rich layered oxide cathodes promise ultrahigh energy density but is plagued by the mechanical failure of the secondary particle upon (de)lithiation. Existing approaches for alleviating the structural degradation could retard pulverization, yet fail to tune the stress distribution and root out the formation of cracks. Herein, we report a unique strategy to uniformize the stress distribution in secondary particle via Kirkendall effect to stabilize the core region during electrochemical cycling. Exotic metal/metalloid oxides (such as Al2O3 or SiO2) is introduced as the heterogeneous nucleation seeds for the preferential growth of the precursor. The calcination treatment afterwards generates a dopant-rich interior structure with central Kirkendall void, due to the different diffusivity between the exotic element and nickel atom. The resulting cathode material exhibits superior structural and electrochemical reversibility, thus contributing to a high specific energy density (based on cathode) of 660 Wh kg−1 after 500 cycles with a retention rate of 86%. This study suggests that uniformizing stress distribution represents a promising pathway to tackle the structural instability facing nickel-rich layered oxide cathodes.

Evaluation of active silica-alumina content and reactivity in bayer process red mud

Cement concrete plays a crucial role in modern construction, but its production process results in significant CO2 emissions, posing a substantial threat to the environment. To achieve green production, the use of industrial waste slag as a raw material for concrete has been widely accepted. This study focuses on the potential utilization of Bayer Process Red Mud (RM), a by-product of the alumina refining process, characterized by high alkalinity and low pozzolanic activity, limiting its application in cement concrete. The reactive activity of RM after calcination treatment was investigated to overcome this challenge and enhance the reactivity of RM. Fourier Transform Infrared Spectroscopy (FTIR) was employed to determine the degree of polymerization of RM at different calcination temperatures, and thus evaluate its pozzolanic activity. Integrating physical tests, chemical experiments, and microscopic analysis, this study thoroughly analyzes the relationships between different evaluation methods and finds a negative correlation between the degree of polymerization and the pozzolanic activity index, boasting a correlation coefficient of 0.904. The results indicate that RM exhibits the highest pozzolanic activity at a calcination temperature of 700 °C. Therefore, this method has been proven effective and can serve as a quick and convenient means of evaluating the pozzolanic activity of RM. The findings of this study are expected to promote the green development of the cement industry, better utilize waste slag resources, reduce CO2 emissions, and enhance the performance of building materials.

Electrochemical detection of nitrite in medical and environmental samples with oxidation modified carbon fiber electrode

The potential toxicity of nitrite to organisms and the environment makes it necessary to build a sensitive and accurate nitrite detection platform. The oxidation-modified carbon fiber electrode (OMCF) with a rougher surface and oxygen-containing functional groups is constructed by a simple high-temperature calcined treatment at 400 °C for 2 h for sensitive detection of nitrite. The amperometric test results exhibit that OMCF has two linear ranges of 1–1000 µM and 1000–6000 µM. Besides, its corresponding sensitivities are 988.57 and 668.51 µA mM−1 cm−2, respectively. The low detection limit is 0.1 µM. Importantly, the OMCF can be used to detect nitrite in a drop of water or medical samples. In addition, the OMCF with a length of 150 cm was successfully synthesized. The nine sections of the above OMCF are randomly selected to detect nitrite, which shows good reproducibility. Therefore, this work provides a facile method for preparing OMCFs with high sensitivity and wide linear range for the electrochemical detection of nitrite in urine and enables large-scale electrode production for medical applications.

Carbon-coated Fe3O4@cotton fiber biomass carbon for the oxygen reduction reaction in air cathode microbial fuel cells

Iron-based oxide catalysts on biomass carbon fibers can jointly use their respective advantages of chemical composition and structure to develop catalysts for the oxygen reduction reaction (ORR). In this study, carbon-coated Fe3O4@cotton fiber biomass carbon (C@Fe3O4@CFBC) was prepared as an ORR catalyst through hydrothermal growth and calcination treatment for air cathode microbial fuel cells (MFCs). The carbon coating layer enhanced the O2 adsorption energy, decreased the overpotential, and promoted surface activation of the Fe3O4 catalyst. The carbon coating layer can modulate the surface electronic structure of the Fe3O4 catalyst with C–O–Fe bonding and improve the electrical conductivity to accumulate electrons on the Fe3O4 surface to enhance the ORR performance. The CFBC supported Fe3O4 nanoparticles to prevent severe aggregation and expose more effective surface-active sites. The C@Fe3O4@CFBC catalyst achieved a high positive half-wave potential (0.801 V) and low Tafel slope (73.7 mV·dec−1) compared with the Pt/C catalyst (0.877 V and 94.3 mV·dec−1). The assembled air cathode MFCs achieved a desirable maximum power density (1059 ± 16 mW·m−2) based on 1266 ± 94 mW·m−2 of Pt/C MFC devices. This work provides a strategy for designing highly active non-precious metal catalysts for air cathode MFCs.

Fe Single-Atoms Combined with Chitosan for Enhanced Electromagnetic Wave Absorption

On account of that the single carbon material possess exceeding electrical conductivity, which will cause impedance mismatch and thus seriously affects the electromagnetic wave (EMW) absorption performance of the material. Therefore, it is an effective method to combine carbon material with magnetic material to make the material have dielectric loss and magnetic loss at the same time. In this paper, magnetic Fe nanospheres were loaded onto the conductive network of chitosan and the composite 800Fe-Chitosan was obtained through freeze drying and calcination treatment. As a result, the composite shows superior EMW absorption performance with a reflection loss (RL) of -40.22 dB and a broad effective absorption bandwidth (EAB) of 4.24 GHz.

Spinel-type high-entropy oxide nanotubes for efficient oxygen evolution reaction

Oxygen evolution reaction (OER) involved 4-electron transfers is generally considered as the bottleneck for electrocatalytic water splitting. High-entropy oxides (HEO) show promising potential for OER due to their flexible structures and tunable compositions. Herein, we report a facile strategy to synthesize spinel-type (FeCoNiMnCr)3O4 HEO nanotubes (NTs) with unique hollow structures by combining electrospinning process and calcination treatment. The (FeCoNiMnCr)3O4 HEO NTs prepared at 400 °C exhibit the low overpotential of 353 mV at 50 mA cm−2 and small Tafel slope of 55.6 mV dec−1 in 1 M KOH electrolyte. The three-dimensional (3D) nanofiber-based architecture ensure the superior stability, as evidenced by the stable current density under continuous OER process for more than 60 h. Meanwhile, the hollow structure provides abundant exposed active sites, which could significantly improve the OER activity. This work provides new design of low-cost and high-efficient HEO with ensemble active sites for OER.

Effect of confined Mn oxides on regulating capability of activated coke for persulfate-based oxidation of a sweetener acesulfame

Mn oxides are confined within the porous structure of activated coke (ACO) via impregnation followed by calcination treatment. The Mn-ACO sample calcined at 600 °C (Mn-ACO600) demonstrated superior performance despite containing only a minute atomic ratio of 0.11 % Mn on its surface. This treatment led to a slight increase in the specific surface area and pore volume of ACO, with a significant enhancement in the proportion of micropores, rising from 54.2 % in ACO to 71.8 % in Mn-ACO600. Raman spectroscopy indicated additional defects in Mn-ACO, while XPS analysis confirmed the coexistence of Mn(II), Mn(III), and Mn(IV) oxides. Although ACO adsorption alone was ineffective in removing acesulfame (ACE), Mn-ACO600 achieved a removal rate of 19.0 %. The introduction of peroxydisulfate (PDS) further boosted the degradation of Mn-ACO600, with a Kapp value that was 2.28 times of that of the combined Mn-ACO600 adsorption and PDS oxidation process, indicating a remarkable synergistic effect. To optimize the experimental conditions, a response surface methodology design analysis was conducted, revealing that solution pH and the dosage of Mn-ACO600 were crucial factors. Furthermore, the study confirmed non-radical oxidizing species, such as 1O2 and h+, played a predominant role in the process, with relatively minor contributions from radical oxidizing species.

TiO2/SiO2 spiral crimped Janus fibers engineered for stretchable ceramic membranes with high-temperature resistance.

The tensile brittleness of ceramic nanofibrous materials makes them unable to withstand the relatively large fracture strain, greatly limiting their applications in extreme environments such as high or ultra-low temperatures. Herein, highly stretchable and elastic ceramic nanofibrous membranes composed of titanium dioxide/silicon dioxide (TiO2/SiO2) bicomponent spiral crimped Janus fibers were designed and synthesized via conjugate electrospinning combined with calcination treatment. Owing to the opposite charges attached, the two fibers assembled side by side to form a Janus structure. Interestingly, radial shrinkage differences existed on the two sides of the TiO2/SiO2 composite nanofibers, constructing a helical crimp structure along the fiber axis. The special configuration effectively improves the stretchability of TiO2/SiO2 ceramic nanofibrous membranes, with up to 70.59% elongation at break, excellent resilience at 20% tensile strain and plastic deformation of only 3.48% after 100 cycles. Additionally, the relatively fluffy ceramic membranes constructed from spiral crimped Janus fibers delivered a lower thermal conductivity of 0.0317 W m-1 K-1, attributed to the increased internal still air content. This work not only reveals the attractive tensile mechanism of ceramic membranes arising from the highly curly nanofibers, but also proposes an effective strategy to make the ceramic materials withstand the complex dynamic strain in extreme temperature environments (from -196 °C to 1300 °C).

Green synthesis of β-cyclodextrin conjugated Fe3O4/NiO nanocomposites and its synergistic effect of adsorption and photocatalytic degradation for Congo red removal

The Fe3O4/NiO magnetic nanomaterials were prepared by microwave-assisted and hydrothermal synthesis in β-cyclodextrin (β-CD) solution, which can be employed as absorbents and photocatalysts for the degradation of Congo red (CR). The XRD, EDX and TEM characterizations were used to determine the structure, composition and morphology of the as-prepared samples. The interaction between Fe3O4/NiO nanoparticles and β-CD molecules was investigated by TGA and FT-IR spectra. The results indicate that β-CD molecules can encapsulate the as-prepared nanoparticles and control the nucleation and growth of Fe3O4/NiO nanocrystals to certain extent. The pyrolysis of β-CD molecules and calcination treatment produced porous structure that provides more adsorption sites for CR molecules. The effect of reaction factors including calcination temperature and pH values was studied to determine the optimum condition. In addition, the thermodynamic and kinetic parameters of CR absorbed on Fe3O4/NiO nanoparticles were measured to understand the adsorption mechanism. The high removal efficiency for CR in aqueous solution was achieved within 60 min of adsorption and 40 min of UV-light irradiation, which can be attributed to the synergistic effect of the adsorption–photodegradation process. The prepared Fe3O4/NiO nanocrystals exhibit high adsorption capacity, magnetic separability, good photocatalytic activity and renewability, making it a potential material for wastewater treatment.

A mesoporous Mo and N Co-doped TiO2 nanocomposite with enhanced photocatalytic efficiency.

This study reports the synthesis of a mesoporous Mo and N codoped anatase TiO2 nanocomposite with many oxygen vacancies using a simple one-step hydrothermal method and subsequent calcination treatment. Both Mo and N were effectively co-incorporated into the anatase phase of TiO2 without MoOx phase segregation. The codoped catalyst demonstrated a mesoporous architecture with a surface area of 107.48 m2 g-1 and a pore volume of 0.2974 cm3 g-1. X-ray photoelectron spectroscopy confirmed that both Mo and N dissolved in the TiO2 lattice and created induced oxygen vacancies. The interaction of the dopants (Mo and N) and oxygen vacancies clearly affected TiO2 crystal formation. Photocatalytic performance of the nanocomposite was investigated in terms of the decomposition of methyl orange at a concentration of 50 mg L-1 in an aqueous solution. The results revealed a significant methyl orange degradation of up to 99.6% after 30 min irradiation under a UV light. The impressive performance of the nanocomposite is assigned to the synergetic effect of important factors, including the co-doping of metallic (Mo) and non-metallic (N) elements, oxygen vacancy defects, bandgap, crystallite size, mesoporous structure, and BET surface area.

Reinforcing the stability of cobalt-free lithium-rich layered oxides via Li-poor Ni-rich surface transformation

We report a lithium-rich layered oxide Li1.2Mn0.6Ni0.2O2 (LMNO) with an electrochemically stable Li-poor nickel-rich surface by simple excessive calcination treatment, greatly suppressing the surface side reactions and Mn-ion dissolution.

Design of β-Mo2C with an appropriate intercalation potential as an anode material toward lithium ion batteries

The advancement of innovative Mo2C anode yet faces the challenge of exploring a simple, convenient and controllable synthetic route. β-Mo2C was prepared by utilizing low-cost hexamethylenetetramine and ammonium molybdate as raw materials and employing simple calcination treatment under N2 atmosphere. When applied as an anode for lithium ion batteries (LIBs), β-Mo2C delivers a satisfactory rate performance (147.0 and 103.4 mAh g−1 at 0.5 and 1.0 A g−1) and excellent cyclic stability (72.2 mAh g−1 at 2.0 A g−1 after 1500 cycles). Meanwhile, a suitable voltage plateau at ∼1.4 V for β-Mo2C also avoids the formation of lithium dendrites to improve the safety of LIBs.

Evaluating lithium slag for geopolymer concrete: A review of its properties and sustainable construction applications

This comprehensive review paper evaluates lithium slag (LS) as a promising precursor for geopolymer concrete, focusing on its workability, strength, durability, and microstructure. In the context of sustainable construction, LS emerges as a vital alternative to conventional cementitious materials, primarily due to the environmental concerns associated with cement production, such as substantial greenhouse gas emissions and air pollution. Geopolymer technology utilizes alkali activators and aluminosilicate-rich materials, offers a reduced environmental footprint and shows comparable performance to traditional cement-based concrete. In particular, LS has gained attention for its potential as an aluminosilicate precursor material in geopolymer concrete. This review investigated the recent advancements in LS-based geopolymers, exploring various processing techniques like mechanical activation, calcination, and chemical treatment to optimize LS geopolymerisation and enhance early strength development. The incorporation of binary/ternary aluminosilicate material is also discussed, aiming to improve crucial properties such as workability, strength, durability, and microstructure. The needs for comprehensive research into LS-based geopolymers to achieve their full potential in sustainable construction, promoting an environmentally friendly approach and contribution to a circular economy in the construction industry are highlighted.

Separation and Recovery of Copper and Nickel in the Leachate of a Waste IC Lead Frame through Synergistic Solvent Extraction Using a Binary Extractant Containing LIX984N and Cyanex302 Followed by Selective Stripping

The IC lead frame is an essential component in semiconductor packaging, primarily composed of a nickel (Ni)–copper (Cu) alloy in which Ni is electroplated onto a Cu substrate. In this study, synergistic solvent extraction using a binary extractant containing LIX984N and Cyanex302, followed by two-stage selective stripping using sulfuric acid (H2SO4) and nitric acid (HNO3) as the stripping agent, was employed to separate and recover Cu and Ni from the leachate of an IC lead frame. The results indicated that under the optimal conditions of synergistic solvent extraction with an extraction pH value of 1, an extractant concentration of 0.015 M LIX984N + 0.0375 M Cyanex302, an extraction aqueous/organic (A/O) ratio of 1:1, and an extraction time of 5 min, the extraction efficiencies for Cu and Ni were 99.8% and 1.17%, respectively. The distribution ratios were DCu 999 and DNi 0.012, resulting in a separation factor of 83,250. In addition, the separation factor was much higher than that of using individual extractant of LIX984N (6208.3) or Cyanex302 (22,185.2). Subsequently, under optimal first-stage stripping conditions, using 0.05 M H2SO4 at a stripping organic/aqueous (O/A) ratio of 1:1, and with a stripping time of 3 min, a stripping efficiency of 99.9% for Ni was achieved. Next, under optimal second-stage stripping conditions, using 5 M HNO3 at a stripping O/A ratio of 2:1, and with a striping time of 3 min, a stripping efficiency of 99.9% for Cu was achieved. Finally, sodium hydroxide (NaOH) was added to the respective stripping solutions to precipitate Ni and Cu ions, followed by calcination treatment for the precipitates to obtain NiO and CuO, respectively. The purity of the former was 99.74% and that of the latter was 99.82%. The results demonstrate that synergistic solvent extraction using a binary extractant containing LIX984N and Cyanex302 can almost entirely extract Cu in the leachate of an IC lead frame at a lower extraction pH and a lower extractant concentration, thus reducing the co-extraction of Ni. In addition, less co-extracted Ni in the organic phase can be selectively stripped using dilute H2SO4, thus reducing the co-stripping of Cu. Hence, the effective separation and recovery of Cu and Ni in IC lead frame leachate can be achieved, which contributes to improving the sustainability of natural resources.

Persulfate catalyst synthesized with waterworks sludge for degrading Safranine T in the presence of boron

ABSTRACT Energy conservation and emission reduction are the general trend of the present world. In this study, a catalyst of 3WSH based on the waste recycle of waterworks sludge (WS) and Chinese herbs was prepared using one-step calcination treatment and then characterized by SEM, XRD, XPS, FTIR and BET. The catalytic performance of 3WSHB for activating potassium persulfate (PDS) was evaluated through the degradation of Safranine T (ST) in the presence of boron powder (B). The effects of vital parameters on ST removal were systematically studied, including PDS concentration, 3WSHB dosage, initial solution pH, B dosage, temperature and coexisting cations. The highest efficiency of ST removal was up to 93.0% under the optimal condition with 1.85 mM of PDS, 0.3 g/L of 3WSHB, 0.35g/L of B, 7 of pH. EPR and free radical quenching experiments demonstrated that •OH was the dominant reactive oxygen species for ST degradation in the PDS/3WSHB/B system. Moreover, the intermediates determined by HPLC-MS indicated that the oxidization of benzene ring substituents in ST and a hydrogen abstraction by electron transfer might occur during ST degradation. The dissatisfied reuse performance of 3WSHB might be attributed to its low Fe content and simple reusing way. The results demonstrate the effectiveness of WS recycling and reuse in the field of pollutant remediation.