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A photocatalysis based g-C3N4 system is a green and eco-friendly method for hydrogen production, but limited activity of g-C3N4 is undesirable. Presently, most of the modification strategies for the g-C3N4-based photocatalytic system are centered on doping and heterojunction engineering outside the bulk phase, and little consideration is given to functional group modification within the bulk phase. Herein, surface C-coupled hydroxylated g-C3N4 photocatalysts for efficient H2 evolution are presented. A C-coupled hydroxylation process is proposed through the reaction of formaldehyde with the unsaturated carbon in the g-C3N4 framework. Compared to pristine g-C3N4 photocatalysts, the surface C-coupled hydroxylated g-C3N4 photocatalyst exhibited over 11.18 times more photocatalytic efficiency for H2 production, and impressive apparent quantum yield. The experimental findings and theoretical calculations reveal that the morphology, photo-response features, and crystal structure are maintained after the introduction of C-coupled hydroxylation on the g-C3N4 surface, but the H2O adsorption and H2 production efficiency of g-C3N4 are significantly increased due to excellent photoinduced carrier migration efficiency. Therefore, the functional modification of g-C3N4 photocatalysts with C-coupled hydroxylation is highly favorable. This work could offer a new and useful protocol for designing highly efficient functional photocatalysts from a structural modification perspective. [ABSTRACT FROM AUTHOR]

The combination of nitrogen and phosphorus compounds has synergistic flame retardant effect, but the addition of low phosphorus content compounds is large, which affects the mechanical properties of polymers. Phosphorus ammonium polyphosphate (APP) with high phosphorus content and graphitic carbon nitride (g-C3N4) doped with SiO2 were used for the flame retardant (CN-Si-APP) of polyamide 6 (PA6). CN-Si-APPs with different APP/CN mass ratio (1, 2.5 and 4) and dosage (7 and 12 wt%) were blended with PA6 via a twin-screw extruder, and their flame retardancy was investigated by limiting oxygen index (LOI), UL-94 test, muffle furnace carbonization test and raman spectroscopy. When only APP added, the coefficient of water absorption (CWA) of composites increased and its tensile strength greatly reduced by nearly 37.1% to 35.39 MPa. The addition of g-C3N4 inhibited the water absorption. When the addition dosage is 7%, the CWA of PA6/APP, PA6/CN-Si-APP2.5, PA6 and PA6/CN were 11.1, 6.86, 5.78 and 4.6%, respectively. SiO2 effectively improved the dispersion of g-C3N4 and the mechanical properties of composites. Thermogravimetric analysis (TGA) showed that the char residue of PA6 composites was improved significantly. The composite with 7 wt% CN-Si-APP4 passed the UL-94 V-0 rating. The LOI value and graphitization degree (ID/IG) of PA6/12 wt% CN-Si-APP2.5 reached 28.7% and 2.93 respectively. Under the same dosage, the graphitization degree of CN-Si-APP2.5 (3.51) was higher than that of g-C3N4 (3.98). The barrier protection of g-C3N4, catalytic effect of APP and SiO2 crosslinking network promoted PA6 to form a dense and stable char layer, which protected PA6 composites from the flame. The strategy of synergistic flame retardant in this paper provides a valuable solution for reducing the amount of flame retardant. [ABSTRACT FROM AUTHOR]

The efficiency of Ni(II) removal from electroplating wastewater is highly correlated with different adsorption materials. A Ca-Si activated mineral adsorbent (CSAM) and two ion-exchange resins (732 and D152) were compared. The adsorption of Ni (II) by three materials is spontaneous and endothermic, and their adsorption capacities are similar (48.66–65.36 mg/g at 318K), but the dosage of CSAM is less (1.0 g/L for 50 mg/L Ni(II)), its adsorption is faster (<5 min) and pH range is wider (2–7). 10% NaCl, 1 mol/L HCl and 10% NaCl +1 mol/L HCl were used as desorbent agents, and CSAM exhibited an extremely low desorption rate (1.49–3.41%). The smaller separation factor (close to 0) and XPS analysis showed that the Ni(II) adsorption on CSAM was an irreversible chemical process, which was different from the three-stage adsorption of resins. The treatment of two kinds of electroplating wastewater with high and low concentration showed that CSAM not only had a higher Ni(II) removal rates (>98.4%), but also could efficiently remove Cu(II) (>98%), total-chromium (>79%) and COD (>66%). The treatment of Ni(II) containing electroplating wastewater with ion-exchange resins is greatly affected by the complexing agent. CSAM is more suitable for the treatment of electroplating wastewater containing various metals and organic matters. [ABSTRACT FROM AUTHOR]

To improve the flame retardancy of PA6/PA66 copolymer, a phosphorus‐nitrogen flame retardant DDP‐M was successfully synthesized via melt condensation reaction between 2‐[(5‐oxo‐6H‐phosphanthridin‐5‐yl)methyl]butanedioic acid (DDP) and melamine (Mel). Its structure, product composition, and thermal stability were characterized by FTIR, nuclear magnetic resonance spectroscopy (NMR), matrix‐assisted laser desorption and ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS), and thermogravimetric analysis (TGA). The results suggested that DDP‐M was a hybrid flame retardant. A series of flame‐retardant PA6/PA66 composites were prepared by melt extrusion. Their thermal stability and flame retardancy were assessed by differential scanning calorimetry (DSC), TGA, limiting oxygen index (LOI), and vertical burning test (UL‐94). The combustion behavior demonstrated that DDP‐M can effectively improve flame retardancy, achieving 32% of LOI value and UL‐94 V‐0 rating with only 9 wt.% addition. No melt dripping was accomplished by adding 12% DDP‐M. The high dose (15%) harmed the flame‐retardant properties. The results of pyrolysis gaseous productions analysis and residual carbon analysis revealed the flame‐retardant mechanism of DDP‐M was a synergistic effect of melamine inducing gaseous phase flame retardancy and highly condensed P‐N char layers inducing condensed phase flame retardancy. The composites retained good mechanical properties due to the good dispersibility and compatibility between polyamide and DDP‐M. [ABSTRACT FROM AUTHOR]

In this work, a novel phosphorus–nitrogen flame retardant (CN‐DOPO), which was successfully prepared via a facile method of graphitic carbon nitride (g‐C3N4) and 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO). Polyamide 6 (PA6) composites were then prepared through melt blending with different ratios of g‐C3N4/DOPO and different contents of CN‐DOPO. CN‐DOPO was characterized and confirmed using X‐ray diffraction (XRD), Fourier transform infrared spectra (FTIR), and scanning electron microscopy (SEM). PA6/CN‐DOPO composites were investigated by limiting oxygen index (LOI), vertical combustion (UL‐94), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), and thermogravimetric analysis‐infrared spectrometry (TGA‐IR). The results indicated LOI value was increased from 23.4% to 29.2% and successfully passed UL‐94 V‐0 rating when the presence of CN‐DOPO increased to 15 wt%. Moreover, mechanical properties of PA6/CN‐DOPO composites had not deteriorated significantly due to CN‐DOPO having better dispersion and compatibility in PA6. The morphological of char layer revealed that CN‐DOPO formed a highly integrated char layer surface during the combustion process, as compared to that of pure PA6. Meanwhile, CN‐DOPO decomposed to release gases could inhibit decomposition by diluting flammable volatiles. Accordingly, the special gas‐condensed phase synergistic flame‐retardant mechanism of PA6/CN‐DOPO was proposed. This work indicated that CN‐DOPO could endow PA6 with highly effective flame‐retardant and good mechanical performance. [ABSTRACT FROM AUTHOR]

Flame‐retardant polyamide 6 (PA6) was prepared by an inorganic‐organic composite (MCN or MgO/g‐C3N4) synthesized by incorporating magnesium oxide (MgO) combined with graphitic carbon nitride (g‐C3N4). As compared to g‐C3N4, MCN possessed a laminate structure, more holes, and a larger specific surface area. The addition of MCN could effectively improve the flame retardancy and mechanical properties of PA6 due to its better compatibility and dispersion in the PA6 matrix. When the addition of MCN was 20 wt%, the vertical combustion performance of the PA6/MCN sample reached flammability rating V‐0 (UL‐94) and the limiting oxygen index (LOI) was up to 32.1%. The results of thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) revealed that the introduction of MCN efficiently enhanced thermal stability of PA6. The morphologies of the char residue observed by scanning electron microscopy (SEM) verified that MCN promoted the formation of sufficient, compact, and homogeneous char layers on the composite's surface during burning. Thus led to increase the char layer strength and improve the flame retardancy of PA6. The thermogravimetric analysis/infrared (TG‐IR) revealed the gas‐phase retardancy mechanism of MCN. Compared with PA6/g‐C3N4, PA6/MCN showed better mechanical properties in terms of flexural strength and tensile strength. [ABSTRACT FROM AUTHOR]

A novel, three-dimensional material of g-C3N4/MgO was prepared by pyrolysis method. The adsorption behavior for Pb(II) onto g-C3N4/MgO was systematically investigated. The adsorption experiments confirmed that the g-C3N4/MgO exhibited remarkable adsorption performance owing to its rough morphology and abundant active sites on the surface. The maximum adsorption capacities for Pb(II) reached to 220.3, 226.2 and 235.1 mg/g at 308 K, 318 K and 328 K, respectively. The optimum adsorbent dosage was 1.0 g/L. The adsorption kinetics and isotherm could be well described by the pseudo-second-order model and Langmuir isotherm model, respectively. The adsorption process was spontaneous and endothermic. [ABSTRACT FROM AUTHOR]

The activated biochar (ABC) was prepared, characterized and examined the feasibility of removing ethylparaben (EP) from aqueous solution. The characterization results showed that ABC possessed multi-porous structure and high surface area. The adsorption isotherm was well fitted the Langmuir isotherm and the adsorption kinetic followed the pseudo-second-order model. The maximum adsorption capacity of EP onto ABC was 349.65 mg/g at 298 K. The adsorption capacity maintained 90.82% after five successive adsorption/desorption cycles. ABC possessed high adsorption capacity, usability and stability, which indicating that ABC has great potential to be a promising adsorbent for removal of EP from aqueous solution. [ABSTRACT FROM AUTHOR]

The carboxyl-modified biochar derived from palm fiber was prepared through pyrolysis and oxidation. The adsorption behavior for Pb(II), Cu(II) and Cd(II) on the carboxyl-modified biochar was systematically investigated. The experimental results demonstrated that the carboxyl-modified biochar exhibited impressive adsorption performance owing to its multi-porous structure and abundant adsorption sites on the surface. The maximum adsorption capacities for Pb(II), Cu(II) and Cd(II) reached 218.5, 132.1 and 79.9 mg/g, respectively. The adsorption kinetics and isotherm could be well described by the pseudo-second-order model and the Langmuir isotherm model, respectively. After five successive adsorption/desorption cycles, the removal efficiency was still more than 90%, 86% and 83% for Pb(II), Cu(II) and Cd(II), respectively. [ABSTRACT FROM AUTHOR]

A novel magnetic biochar was prepared via pyrolysis method and modification. The influence factors of contact time, initial concentration, temperature, and pH on the adsorption were investigated. The experimental results exhibited that the adsorption ability of methyl salicylate onto biochar was higher than that of phenol and para-chlorophenol under the same condition, which may be owing to the effect of hydrogen bonding, hydrophobicity, and π-π interaction. The maximum adsorption capacities of phenol, para-chlorophenol and methyl salicylate were 62.6, 131.6, and 169.7 mg/g at 298 K, respectively. This magnetic biochar exhibited high reusability (retained 82.1% after five cycles) and sharply magnetic performance (21.4emu/g). [ABSTRACT FROM AUTHOR]

With the increasing concern about the sustainable chemistry, a fern plant-cyclosorus interruptus that contains plentiful multi-porous structure and puckered morphology can be considered as an ideal carrier to load various nanoparticles for synthesis of impressive functional materials. Herein, magnetic biomaterial was fabricated via coating a layer of 3-aminopropyltriethoxysilane (AS) on the surface of activated cyclosorus interruptus after incorporated with Fe 3 O 4 nanoparticles, and exhibited highly effective separation and impressive adsorption ability for lead ion from aqueous solution. Their morphology and property were investigated. Furthermore, the adsorption equilibrium isotherms, kinetics and thermodynamics of lead ion onto the magnetic biomaterial were studied to evaluate the performance of their practical application. These results indicated that the magnetic property of the prepared adsorbent could be easily tailored by adjusting the feedstock ratio, and these adsorption processes were endothermic and spontaneous reaction. The maximum adsorption capacity of lead ion on the bio-based magnetic adsorbent was 133.3 mg/g. The results of five successive adsorption/desorption cycles exhibited that all the adsorption abilities maintain above 90% of the original adsorption ability. [ABSTRACT FROM AUTHOR]

A novel magnetic bio-material (MCIT) was synthesized via coupling reaction and functional modification after load of Fe 3 O 4 nano-particle on the puckered surface of cyclosorus interruptus (CI). The synthesized material was characterized by fourier transform infrared (FTIR), field emission scanning electron microscope (FE-SEM), X-ray photoelectron spectroscopy (XPS) and X-ray powder diffractometer (XRD). The influence factors like pH, temperatures, contact time, initial concentration and cycle times on the adsorption of Hg (II) in aqueous solution were studied. Adsorption isotherm, kinetics, selectivity and mechanism were investigated. The results indicated that the isotherm model well agreed with monolayer adsorption model. The adsorption process could be divided into three steps, which included a fast step controlled by chemical adsorption, a slow step limited by intraparticle diffusion and an equilibrium stage. The maximum adsorption capacity of Hg (II) was 385.3 mg/g at 318 K. MCIT possessed high reusability (retained 93% after five successive cycles) and sharply magnetic nature (9.5 emu/g), which endowed it easy and efficient separation from aqueous solution. [ABSTRACT FROM AUTHOR]

The article discusses research done on the development of a synthetic strategy for high-flow nylon 6 by in situ polymerization. The results indicated the reaction of generation 1, 2, 3 polyamidoamine (PAMAM) dendrimers with p-phtahlic acid. The researchers did not observe any decline in tensile strength with the elongation at break declining by 20 to 35 percent.

A novel g‐C3N4/MnO2 composite was prepared by in situ deposition of MnO2 on graphitic carbon nitride (g‐C3N4) nanosheets, and its adsorption properties were evaluated for removal of Pb (II) in aqueous. Fourier transform‐infrared, spectrometer scanning electron microscopy and transmission electron microscopy characterization showed the g‐C3N4/MnO2 composite had a two‐dimensional/two‐dimensional (2D/2D) structure with ample active sites. The Brunauer–Emmett–Teller specific surface area of g‐C3N4/MnO2 composites (234.9 m2/g) was 13.5 times larger than that of g‐C3N4 (17.37 m2/g), providing better conditions for adsorption. The adsorption kinetic data were better fitted with the pseudo‐second‐order model. The Langmuir model was more suitable for describing the experimental equilibrium data of g‐C3N4/MnO2, and the maximum adsorption capacity was 204.1 mg/g for Pb (II). The adsorption of g‐C3N4/MnO2 composite for Pb (II) was an endothermic and spontaneous process, and reached adsorption equilibrium rapidly within initial 150 min. This composite was an excellent adsorbent because of its higher adsorption capacity and facile preparation progress. [ABSTRACT FROM AUTHOR]

[Display omitted] • Amidoxime resin modified by PAMAM was synthesized for uranium adsorption. • Dendrimer modification greatly improved the adsorption capacity of the chelating resin. • PAMAM modification had little effect on the adsorption selectivity of U(VI). • The introduction of PAMAM reduced the desorption rate of the chelating resin. Uranium adsorption materials need to consider both adsorption capacity and selectivity. Based on the high adsorption capacity of polyamidoamine (PAMAM) dendrimer and the high selectivity of amidoximated (AO) resin for U(VI), a novel PAMAM modifed AO chelating resin (PS-PAMAM-AO) was prepared and used for U(VI) adsorption in aqueous. For comparison, a common AO resin (PS-AO) was prepared based on ammoniated poly(styrene- co -divinylbenzene) bead (PS-NH 2). The synthesized resins were characterized by Fourier transform infrared spectra (FT-IR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The factors affecting adsorption such as solution pH and temperature, contact time and initial U(VI) concentration were investigated. PS-PAMAM-AO had the largest adsorption capacity (167.8 mg/g, at pH 5.0 and 313 K with initial U(VI) concentration 300 mg/L) compared with its precursor (PS-NH 2 and PS-PAMAM) and PS-AO. Kinetic and thermodynamic studies showed its U(VI) adsorption was a chemical and rate-limiting process and conformed to the Langmuir isothermal model. The adsorbed U(VI) can be desorbed with 10 % NaCl + 1 mol/L HCl, and the desorption rate reached 94.1 %. When the concentration of coexisting NaCl increased from 0.0 to 1.0 mol/l, the U(VI) adsorption capacity of PS-PAMAM-AO decreased to 69.9 %, similar to that of PS-AO (77.4 %), PAMAM modification did not significantly affect the adsorption selectivity of amidoximated resin. [ABSTRACT FROM AUTHOR]

Continuous rice cultivation and excessive use of chemical fertilizers result in soil acidification and heavy metal pollution in southern China. An activated Ca Si mineral remediation material (CSRM) was innovatively prepared by two-stage modification (calcination with mixed salts and the hydrothermal activation) of primary aluminosilicate Potash feldspar. Based on the excellent results of previous pot experiments, this material was used for in situ remediation of cadmium contaminated paddy fields. Adding 4500 kg/hm2 of the material, the cadmium contents in rice and the available cadmium contents in soil was reduced significantly by 41.43%–73.32% and 16.67%–31.13%, accompanied by the increase of soil pH 0.68–0.82 and rice yield 4.24%–11.22%. To further study the remediation mechanism of cadmium, the composite was used for Cd(II) removal in aqueous solution, in combination with SEM, EDX, XPS, XRD, XRF, and BET analysis. The adsorption isothermal data was more suitable with the Langmuir model, and the kinetics can be well described by the pseudo-second-order model. The isothermal study also demonstrated an adsorption process on homogeneous surface along with monolayer adsorption and the maximum capacity obtained from the Langmuir model was 273.2 mg/g at 328 K. By instrumental analysis, it could be known that stable carbonates and silicates were formed by the interaction of materials with cadmium ions, and this process was feasible, spontaneous and endothermic. Ion exchange was found to be the most important chemical process, followed by precipitation, surface complexation and adsorption. The porosity of clay was another significant reason for the removal of heavy metals by adsorption mechanism. Unlabelled Image • The activated Ca-Si mineral remediation material can reduce the cadmium contents in rice and the available cadmium contents in soil significantly. • Cadmium ion was immobilized by ion exchange, precipitation, surface complexation and adsorption. • Ion exchange was found to be the most important chemical process. • The immobilization process of cadmium owns long-term effect and high stability. [ABSTRACT FROM AUTHOR]

A novel Sr-doped P-Na 0.57 Sr 0.05 Mn 0.6 Ni 0.2 Co 0.2 O 2 consisting of multiple-layer oriented stacking nanoflakes with Na+/vacancies is constructed via a sol-gel method. • A P2 type compound consisting of multiple-layer oriented stacking nanoflakes was synthesized. • Sr2+ is embedded in the sodium ion layer to increases the spacing of crystal layers. • Na 0.57 Sr 0.05 Mn 0.6 Ni 0.2 Co 0.2 O 2 cathode exhibits excellent cyclic and rate performance. • It exhibits low transport energy barrier due to Na+/vacancies and wide ionic channels. Sodium ion batteries (SIBs) are an attractive option for energy storage because of their low cost and extensive Na resources. A novel Sr-doped P-type Na 0.57 Sr 0.05 Mn 0.6 Ni 0.2 Co 0.2 O 2 (NSMNC) consisting of multiple-layer oriented stacking nanoflakes is constructed via a sol-gel method. It is the first time that high-valence metal ions with large radius are introduced into the sodium ionic layer to optimize its structure. The substitution of bivalent strontium for monovalent sodium leads to the formation of equivalent Na+/vacancies. Meanwhile, the intercalation of strontium enlarges the cell parameters, providing wide channels for ionic transport. The electrode exhibits a reversible capacity of 120.9 mAh g−1 at 0.1C with retention up to 85.6% after 200 cycles. Besides, it still keeps a capacity of 101.1 mAh g−1 at 1C with high retention of 81.5% after 200 cycles. Owing to the Na+/vacancies and wide ionic channels, NSMNC shows excellent ionic diffusion ability and low transport energy barrier. This work offers a feasible strategy for the development of promising layered oxide cathode materials for SIBs. [ABSTRACT FROM AUTHOR]

Fused deposition modeling (FDM) is widely used in the rapid prototyping of polymers. Polyamide (PA) has excellent mechanical properties, but its application in FDM is limited due to its high water absorption, warpage, and forming shrinkage. The material of the filament and the printing parameters of the printer are two critical aspects that affect the performance of a component. The prepared PA6/PA66 (composite polyamide [COPA], PA6:PA66 = 85:15) composite (COPA: acrylonitrile butadiene styrene [ABS]: maleic anhydride grafted acrylonitrile butadiene styrene [ABS-g-MAH]: polyethylene = 800:133:67:100) has low water absorption (0.39%) and high dimensional stability, which has a good application prospect in FDM. The influence of eight FDM parameters, including three rarely reported, on the properties of PA6/PA66 composite specimens was investigated by the Taguchi method. The significance of influencing factors was evaluated by analysis of variance (ANOVA) and the stability by signal-noise ratio. When the layer thickness was 0.15 mm, the infill pattern was zigzags, the build plate adhesion type was brim, and the distance from the nozzle to the printing platform and the layer thickness (ΔL) was 0.05 mm; the specimens' dimensional accuracy, surface quality, and mechanical properties were better than other levels. The layer thickness and infill pattern were the two most important factors. The switch of the cooling fan and the temperature printing platform played a significant role in the specimens' dimensional accuracy and surface quality. ΔL tremendously influenced the thickness and warping degree of the specimens. The preparation of high-performance PA composites and the investigation of multiparameters by the Taguchi method provide a possible solution for applying polyamide in FDM., Competing Interests: We declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the article entitled “The influence of fused deposition modeling parameters on the properties of PA6/PA66 composite specimens by the Taguchi method and ANOVA” for publication in 3D Printing and Additive Manufacturing. There is no professional or other personal interest in any product, service, or company that could be construed as influencing the position presented in, or the review of, the article. All funding sources supporting the work and the institutional or corporate affiliations of the authors were acknowledged., (Copyright 2024, Mary Ann Liebert, Inc., publishers.)

Activated mineral adsorbent (AMA) was prepared via double salts (Na 2 SO 4 and CaCO 3 ) heat treatment activation of solid-state potassium feldspar. Adsorption performance of AMA for Cd(II) and Pb(II) was investigated by batch mode and factors affecting adsorption including pH value, initial concentration of adsorbate, contact time, adsorbent dosage and temperature on adsorption performance for Cd(II) and Pb(II) were studied. The results indicated that the adsorption process was pH dependent, endothermic and spontaneous. When the adsorption process of Cd(II) and Pb(II) on AMA reached equilibrium, the maximum saturated adsorption capacities were 263.16 and 303.03 mg/g for Cd(II) and Pb(II) ions, respectively, showing higher adsorption removal efficiency. The Langmuir adsorption isotherm and pseudo second kinetic equation could well fit the adsorption process of Cd(II) and Pb(II) by AMA. Besides, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques were also performed to further reveal the adsorption mechanism. The results indicated that ion exchange, precipitation and adsorption played an important role in adsorption process. From the investigation, it was concluded that AMA was an excellent adsorbent with the advantages of environment-friendly, inexpensive, facile preparation and higher adsorption capacity of toxic Cd(II) and Pb(II) ions.

A novel composite (nZVI@K-GCN) was firstly synthesized by liquid phase reducing nanoscale zero-valent iron (nZVI) on potassium-doped graphitic carbon nitride (K-GCN). The results of Fourier transform infrared (FTIR) spectrometry, X-ray diffraction (XRD), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) suggested that nZVI@K-GCN possessed abundant active functional groups such as terminal amino-groups (-NH or -NH 2 groups) and -OH, and the specific surface area and pore volume from BET of nZVI@K-GCN were 4.7 times and 3.7 times higher than that of graphitic carbon nitride (GCN), respectively. These properties showed that the composite was especially suitable for heavy metal treatment. The application of the composite in the removal of chromium(VI) from aqueous solution showed that the maximum adsorption capacity of nZVI@K-GCN towards Cr(VI) was 68.6 mg/g at 308 K when the initial concentration of Cr(VI) was 30 mg/L, and more than 99% removal was obtained at pH = 3. This adsorption was an endothermic and spontaneous process. XPS patterns and batch experiments proved that complexation, electrostatic attraction and reduction precipitation were the main adsorption mechanism for Cr(VI) on nZVI@K-GCN.

A novel magnetic bio-adsorbent (MCIA) was developed, characterized and tested for its Cd(II) removal from aqueous solution. MCIA could be easily separated from the solution after equilibrium adsorption due to its super-paramagnetic property. The functional and magnetic bio-material was an attractive adsorbent for the removal of Cd(II) from aqueous solution owing to the abundant adsorption sites, amino-group and oxygen-containing groups on the surface of Cyclosorus interruptus. The experimental results indicated that the MCIA exhibited excellent adsorption ability and the adsorption process was spontaneous and endothermic. The adsorption isotherm was consistent with the Langmuir model. The adsorption kinetic fitted the pseudo-second-order model very well. The maximum adsorption capacity of Cd(II) onto MCIA was 40.8, 49.4, 54.6 and 56.6 mg/g at 293, 303, 313 and 323 K, respectively. And the MCIA exhibited an excellent reusability and impressive regeneration. Therefore, MCIA could serve as a sustainable, efficient and low-cost magnetic adsorbent for Cd(II) removal from aqueous solution.

Ti/SnO(2)-Sb(2)O(3)/SnO(2)-Sb(2)O(3)-CeO(2) anodes were prepared by brush coating with high temperature oxidation. The anodes were characterized by X-ray diffractometer (XRD), scanning electron microscope and cyclic voltammetry. The surface of the electrode shows more compact and exist shallower mud cracks than the others by coating with 1% Ce to the surface of Ti/SnO(2)-Sb(2)O(3) electrode. The XRD patterns show that as-prepared electrodes are SnO(2) and TiO(2). The electrode with 1% Ce dopant shows the highest efficiency in the electrolysis of caprolactam wastewater. The oxygen evolution potential is about 1.75 V, the removal rate of chemical oxygen demand is 50%, and the biochemical oxygen demand is 353 mg/L for 5 h at a current of 0.12 A.