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As one of the most promising electrode materials for supercapacitors, MnO2 has the problems of low voltage window and poor conductivity. It has been shown that Al-doped MnO2 can effectively improve the voltage window and specific capacitance, and polyaniline loading can further bring higher specific capacitance. Polyaniline-supported Al-doped MnO2 carbon cloth-based flexible electrode material (PANI@Al-MnO2@CC) was prepared by hydrothermal reaction and in-situ polymerization. Compared with MnO2 electrode material, the working voltage window of PANI@Al-MnO2@CC is increases to 1.25 V, the area specific capacitance can be as high as 1016 mF cm−2, and still maintain 80.1% of the original value at 20 mA cm−2 after 5000 cycles. Furthermore, the voltage window of the flexible symmetrical supercapacitor made of the material can reach 0–2.4 V, and has a super large area specific capacitance of 149.75 mF cm−2 and a high energy density of 1.60 mWh cm−3 at 6 mA cm−2.

The point of this review is mainly focusing on the safety and practicability of solid-state lithium ion battery. And this review emphatically discusses and analyzes these practical manufacturing methods and strategies by illustrating some novel and excellent reported examples instead of barely collecting and classifying these new materials over the years. Based on the current industrial technology and market requirements, we summarize four types of most practical solid-state electrolytes (polymer gel, PEO-based, garnet-type and sulfide-type electrolyte) whose potential of application, strategy of improvement and possibility of mass production are all analyzed in this review. Li ion transport mechanisms in different electrolytes, which are commonly accepted in recent years, are summarized and stated as well. Besides, the key interfacial problems of electrolytes and electrodes for solid batteries is emphatically discussed and we also sort out some useful methods for actual production. And there are some interesting and novel content in this paper, which is that the lithium metal is not considered as an anode material because we think that is not realistic and economical for industrial manufacture in recent years and the polymer gel is analyzed to be a great transition electrolyte from liquid electrolyte batteries to all-solid-state batteries.

The drawback of traditional capacitors with low energy density forces people to develop high-performance supercapacitor materials. Herein, the Al-doped MnO2 @ carbon cloth is selected as the ideal electrode material. A typical hydrothermal reaction can be used to synthesize Al-doped MnO2 @ carbon cloth at 150 °C for 4 h. Its operating window can be successfully expanded from 0–0.8 to 0–1.2 V, and the areal-specific capacitance reaches 1043 mF cm−2, keeping 91.1% of the original after cycling 5000 times at a current density of 20 mA cm−2. Using the electrode materials designed above, the flexible symmetrical supercapacitor is successfully assembled. This device shows a greater operating window of 0–2.3 V, a superior large areal-specific capacitance of 521.91 mF cm−2, and the energy density remarkably reaches 4.72 mWh cm−3. After 100 bending cycles, there is also basically no loss in performance. This study highlights the promising prospects of the improvement of MnO2 @ CC materials.

This work presents facile preparation processes of multiphosphonic acid functionalised multi-walled carbon nanotubes (HEDP-MWCNTs and ATMP-MWCNTs), which have been characterised by FT-IR, XPS, X-ray diffraction, TGA, and SEM, and have employed for heavy metal ions adsorption. The adsorption properties of MWCNTs, HEDP-MWCNTs, and ATMP-MWCNTs for gold ions, cadmium ions, copper ions, lead ions, nickel ions, cobalt ions, zinc ions, and chromium ions have been investigated, the experimental results reveal that the functionalised samples HEDP-MWCNTs and ATMP-MWCNTs have excellent adsorption properties for Pb(II) and Au(III), respectively. The investigation results on their adsorption selectivity represent that in the binary heavy metal ion systems, HEDP-MWCNTs/ATMP-MWCNTs has displayed a strong affinity for Pb(II)/Au(III) and even could exhibit 100% selectivity while coexisting with copper ions, nickel ions, cobalt ions, zinc ions, chromium ions, or cadmium ions. Furthermore, the adsorption kinetics of HEDP-MWCNTs for Pb(II) and ATMP-MWCNTs for Au(III) have also been studied at different solution temperatures. All these research work results show that two novel functionalised adsorbents HEDP-MWCNTs and ATMP-MWCNTs have shown excellent adsorption properties for heavy metal ions and they can be used in wastewater treatment, especially for lead/gold ions removal.

Subnanometric Pd clusters confined within zeolite crystals was fabricated using zeolitic seeds with premade [Pd3Cl(PPh2)2(PPh3)3]+ clusters under hydrothermal conditions. Characterization of the Pd3@Beta catalysts indicate that the Pd clusters confined in the channels of Beta zeolite exhibit better dispersion and stronger interaction with the zeolite support, leading to stabilized Pd species after heat treatment by high temperature. In the model reaction of toluene combustion, the Pd3@Beta outperforms both zeolite-supported Pd nanoparticles prepared by conventional impregnation of Pd3/Beta and Pd/Beta. Temperatures for achieving toluene conversion of 5%, 50% and 98% of Pd3@Beta are 136, 169 and 187 °C at SV = 60 000 mL g−1 h−1, respectively. Pd3@Beta could also maintain the catalytic reaction for more than 100 h at 230 °C without losing its activity, an important issue for practical applications. The metal-containing zeolitic seed directed synthesis of metal clusters inside zeolites endows the catalysts with excellent catalytic activity and high metal stability, thus providing potential avenues for the development of metal-encapsulated catalysts for VOCs removal.

The mechanical properties of concrete can degrade significantly under high temperature, posing a threat to the safety of structures. In this work, a novel bio-inspired cement-based composite material that can improve the fire resistance of engineering structures is put forward. This bio-inspired cementitious system, which functions in a manner similar to that of sweat glands and skin in the human body, consists of APP-PER-EN composite, synthetic reinforcing fibers, and concrete binder. The APP-PER-EN composite is mainly composed of ammonium polyphosphate, pentaerythritol, and melamine, with low-density polyethylene as the base material, which is prepared by melt compounding in a twin-screw extruder followed by grain cutting molding technique. At the micro level, multiple analysis methods are used, including X-ray diffraction, Fourier transform infrared ray, thermo-gravimetric analysis, differential scanning calorimeter, and scanning electron microscopy, to characterize the thermal and flame retardant behavior of this novel composite. At the macro level, the one-side heating tests indicate that the thermally triggered fire-resistant system can exhibit significant thermal insulation effect through melting, connecting, foaming, and overflowing. Therefore, the novel composite system is expected to exhibit a promising prospect in the fire resistance of engineering structures.

Carbon-based materials, as electrodes for supercapacitors, have attracted tremendous attention. Therefore, nitrogen-doped porous carbons (NPCs) were prepared through a facile carbonization/activation strategy by treating different mass ratios of melamine-urea-formaldehyde resin and KOH. It is clearly demonstrated that because of the introduction of KOH, the resulting NPCs were shown to have increased specific surface area and a rich pore structure, and the best sample possessed a large specific surface area of 2248 m2 g-1 and high N content, which contributed to the good electrochemical performance for supercapacitors. Accordingly, a three-electrode system assembles NPCs as an electrode using aqueous KOH solution; the specific capacitance was 341 F g-1 under the current density of 1 A g-1 and retained a specific capacitance of almost 92% after 5000 cycles. The maximum energy output for a symmetrical solid-state supercapacitor with NPCs as the electrode material was 9.60 W h kg-1 at 1 A g-1. NPCs have promising applications on high-performance supercapacitors and other energy-storage devices.

The development of simple and feasible methods to synthesize highly efficient adsorbents is the key to low-cost gas purification. Here we developed an in-situ amorphous cobalt template method based on the synergistic effect of precursor to synthesize nitrogen doped unimodal ultramicropores carbon nanosheets Co-NDPCs with high nitrogen content (up to 11.74%), large specific surface area (up to 1187 m2 g−1) and unimodal ultramicropore. As an adsorbent, the Co-NDPCs exhibit unprecedented C2H2, C2H6, C3H8 and CO2 uptake capacities of 6.7, 5.9, 7.4 and 5.6 mmol g−1, respectively, and the corresponding x/CH4 and CO2/N2 IAST selectivities are as high as 75.3, 65.9.1743.6, 11.4 and 74.7 at 298 K and 1 bar. More importantly, this method effectively avoids the defects of traditional activation or template method, such as corrosiveness, poor safety and complicated process, indicating that Co-NDPCs is a promising adsorbent for CH4/C2H2/C2H6/C3H8/CO2/N2 capture and separation.

The adsorption behavior of polyamidoamine (PAMAM) dendrimers functionalized silica (SG-G0∼SG-G4.0) for Cd(II) from aqueous solution was investigated by combining experimental and theoretical method. The influences of dendrimer generation, terminal functional group, solution pH, contact time, temperature, as well as the initial concentration of Cd(II) on the adsorption behavior were explored. Static adsorption indicates that the adsorption capacity increases first and then decreases with the increase of dendrimer generation, SG-G2.0 and SG-G2.5 possess the highest adsorption capacity for amino- and ester-terminated PAMAM functionalized silica, respectively. The optimal adsorption pH value is 6 for all the adsorbents. Kinetic adsorption implicates that the adsorption can approach equilibrium at about 200 min. The kinetic adsorption follows pseudo-second-order kinetic model and is dominated by film diffusion. The isotherm adsorption demonstrates that the adsorption favors high concentration and the adsorption capacity first increases and then decreases with the increase of temperature. Adsorption isotherm process can be well described by Langmuir model. FTIR technique and DFT calculation reveal that the involvement primary and secondary nitrogen atoms, as well as carbonyl oxygen atoms dominate the adsorption. As SG-G0∼SG-G4.0 displays excellent adsorption performance for Cd(II), they could be potentially used as effective adsorbents for the decontamination of aqueous Cd(II).

In this paper, Fe3O4 was loaded on the surface of halloysite nanotubes (HNTs) by a simple one-pot coprecipitation method to prepare Fe3O4/HNTs nanocomposites (Fe3O4/HNTs) for arsenic removal from water. The growth mechanism and the arsenic removal performance of the nanocomposites were investigated. The morphology of Fe3O4/HNTs varied as the mass ratio of the total iron salts (Fe3+: Fe 2+ = 2:1) to HNTs changed. A novel cactus-like Fe3O4/HNTs was obtained when the ratio is 3:1. The removal efficiency of arsenite (As (III)) and arsenate (As (V)) by the cactus-like Fe3O4/HNTs could reach 98.56% and 99.62%, respectively. Much more, the removal efficiency of As (III) of the cactus-like Fe3O4/HNTs is higher than that of most of the other materials reported under the same conditions. In addition, the cactus-like Fe3O4/HNTs showed good reusability, with an arsenic removal efficiency of up to 83.36% after 6 times of reuse. Adsorption kinetics and isothermal adsorption studies have shown that adsorption is a chemical process with a maximum adsorption capacity of 408.71 mg As(III)/g and 427.72 mg As(V)/g, respectively. The facile preparation method, excellent arsenic removal performance and reusability make the cactus-like Fe3O4/HNTs a potential adsorbent for sustainable arsenic removal from contaminated water.

Heavy metal pollution to aqueous media is an important issue for environmental sustainability. A simple strategy for the synthesis of an efficient adsorbent is strongly desired for water remediatio...

Recently, design of cost-effective multifunctional electromaterials for supercapacitors and oxygen evolution reaction (OER) and enhancing their functionalities have become an emphasis in energy storage and conversion. Herein, a series of cheap and functional phosphate composites with different ratios of cobalt and nickel are synthesized using a simple polyalcohol refluxing method, and their excellent capacity and OER properties are systematically studied. Notably, owing to the different major role of Co and Ni elements in the phosphate composites for capacity and OER, the optimal electroconductibility, structural adjustment, electrochemical active sites, and activities for capacity and OER are obtained from the composites with the different ratios of Co/Ni. In addition, using high-capacity BiPO4 (BPO) as the negative electrodes, the new type of all-phosphate asymmetric supercapacitor (CNPO-40//BPO) shows a high energy density and reaches 36.84 W h kg-1 at a power density of 254.52 W kg-1. Its cyclic stability is also more excellent than that of the CNPO-40//AC device using commercial activated carbon as the negative electrodes. This study is beneficial to the more in-depth research on efficient dual-function electromaterials in capacity and OER and provides a high-efficient way to improve the practicality of asymmetric supercapacitors using the high-capacity Bi-based electromaterials as the negative electrodes.

Nanoplastics (NPs) have been identified as newly emerging particulate contaminants. In marine environments, the interaction between NPs and other engineered nanoparticles remains unknown. This study investigated the cotransport of NPs with fullerene (C60) in seawater-saturated columns packed with natural sand as affected by the mass concentration ratio of NPs/C60 and the hydrochemical characteristics. In seawater with 35 practical salinity units (PSU), NPs could remarkably enhance C60 dispersion with a NPs/C60 ratio of 1. NPs behaved as a vehicle to facilitate C60 transport by decreasing colloidal ζ-potential and forming stable primary heteroaggregates. As the NPs/C60 ratio decreased to 1/3, NPs mobility was progressively restrained because of the formation of large secondary aggregates. When the ratio continuously decreased to 1/10, the stability and transport of colloids were governed by C60 rather than NPs. Under this condition, the transport trend of binary suspensions was similar to that of single C60 suspension, which was characterized by a ripening phenomenon. Seawater salinity is another key factor affecting the stability and associated transport of NPs and C60. In seawater with 3.5 PSU, NPs and C60 (1:1) in binary suspension exhibited colloidal dispersion, which was driven by a high-energy barrier. Thus, the profiles of the cotransport and retention of NPs/C60 resembled those of single NPs suspension. This work demonstrated that the cotransport of NPs/C60 strongly depended on their mass concentration ratios and seawater salinity.

In this study, solvothermal method was adopted to successfully prepare graphene oxide (GO) supported SnO2 nanocomposites using tin tetrachloride pentahydrate and graphene oxide as raw materials, tetra-methyl ammonium hydroxide (TMAH) as a control agent. The synthetic materials presented the efficient capacity in the photocatalytic degradation and photoelectric conversion. In the photocatalytic degradation of rhodamine B (RB) and methylene blue (MB), sample SnO2-0.1% GO showed the optimal photocatalytic efficiencies for RB (97.26%) and MB (89.43%) degradation. According to the different degradation performances of RB and MB functional groups, we reasonably explained the electron transfer mechanism at the interface of SnO2-GO nanomaterials, and verified it in the experiment of photoelectric conversion proceed combined with titanium dioxide nanotube arrays (TiO2NTs). The enhanced photocurrent density and stability can also be effectively improved due to the effective photoelectron transfer from SnO2 to GO surface.

Temperature and pH double-response poly(t-butyl acrylate)-b-poly{[2-(dimethylamino) ethyl methacrylate]-co-[poly(ethylene glycol) methyl ether methacrylate]} (PtBA-b-P(DMAEMA-co-PEGMEMA)) were successfully prepared by RAFT polymerization and could be self-assembled into micelles. 1H NMR, UV-vis absorbance and DLS measurements were used to characterize their structures and self-assembly behaviors. At the same time, the adsorption of organic dyes and the control of drug release were also introduced. The results showed that the critical micelle concentration of PtBA-b-P(DMAEMA-co-PEGMEMA) was 2.55 mg/L. As the value of pH increased from 2 to 11, their particle size decreased from 178 nm to 130 nm. PtBA-b-P(DMAEMA-co-PEGMEMA) was also temperature responsive, with the hydrophobic block grows, the temperature of the particle mutation would increase. Therefore, PtBA-b-P (DMAEMA-co-PEGMEMA) could control the transfer and release of organic dyes such as methyl red and dithizone through their pH-sensitive properties, and the process had good reversibility. Meanwhile, PtBA-b-P(DMAEMA-co-PEGMEMA) micelles could also deliver some specific hydrophobic anticancer drug, such as camptothecin (CPT). In conclusion, the copolymers synthesized in this work have potential applications in the fields of environmental protection and drug delivery.

Carbon microfibres (CMFs) were synthesised on SiO2 particles by catalytic chemical vapour deposition at 1200°C using ethanol as carbon precursor, iron nitrate as the catalyst precursor, and nitrogen as a carrier gas. The structure and morphology of the products were characterised by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy and Raman spectroscopy. CMFs obtained after a deposition time of 5 h have a diameter of 5–10 μm and a length of a few hundred micrometres. In the deposition process, Fe–Si–O–C droplets were first formed on the surface of SiO2 particles, and then carbon fibres grew as a result of the catalysis of the droplets. Carbon fibres have the higher graphitic structures when the deposition process is conducted at 1200°C.

A series of one-dimensional column experiments were conducted to investigate the transport and retention of micron-sized plastic spheres (MPs) with diameters of 0.1–2.0 μm in seawater-saturated sand. In seawater with salinity of 35 PSU (practical salinity units), the mass percentages recovered from the effluent (Meff) of the larger MPs increased from 13.6% to 41.3%, as MP size decreased from 2.0 μm to 0.8 μm. This occurred because of the gradual reduction of physical straining effect of MPs in the pores between sands. The smaller MPs (0.6, 0.4, and 0.1 μm) showed the stronger inhibition of MPs mobility, with Meff values of 11.5%, 11.9%, and 9.8%, respectively. This was due to the lower energy barriers (from 108 kBT to 16 kBT) between the smaller MPs and the sand surface, when compared with the larger MPs (from 296 kBT to 161 kBT). In particular, the aggregation of MPs (0.6 or 0.4 μm) triggered a progressive decrease in MP concentration in the effluent. Retention experiments showed that the vertical migration distance of most MP colloids was 0–4 cm at the inlet of column. For 0.6 or 0.4 μm MPs, the particles were concentrated over a 0–2 cm vertical distance. Moreover, the salinity (35–3.5 PSU) did not affect the transport of the larger MPs (2.0–0.8 μm). However, as seawater salinity decreased from 35 PSU to 17.5 or 3.5 PSU, the aggregation of the smaller MPs (0.6–0.1 μm) was dramatically inhibited or completely prevented. Meanwhile, ripening of the sand surface by the MPs (0.6 and 0.4 μm) no longer occurred. By contrast, all MPs in deionized water (0 PSU) achieved complete column breakthroughs because of the strong repulsive energy barrier (from 218 kBT to 4192 kBT) between the MPs and the sand surface. Consequently, we find that the transport and retention of MPs in sandy marine environment strongly relies on both the MP size and the salinity levels.

Porous carbons with large specific surface area and high structural stability are conducive to Li + diffusion and cycling performance of lithium ion batteries. In this paper, porous carbon/α-Fe 2 O 3 composites were in situ synthesized using water soluble phenolic resin as carbon precursor and environmentally benign NaCl as porogen. The interaction between the metal ions and hydroxyl groups in the resin facilitates the self-assembly of the precursors. The presence of NaCl enables the uniform dispersion of ferrous gluconate in the phenolic resin and prevents the aggregation of α-Fe 2 O 3 during the later thermal treatment. When applied as anode materials for lithium ion batteries, the porous carbon provides short diffusion pathways for Li + ions and adequate buffer space to accommodate the volume change of α-Fe 2 O 3 during the discharge/charge process, leading to a high reversible capacity of 1272 mAh g −1 at 100 mA g −1 after 200 cycles, which is much higher than that of carbon/α-Fe 2 O 3 without addition of NaCl. This strategy provides a simple and low-cost way for the mass production of novel anode materials of lithium ion batteries.

A tannic acid-Fe coordination compound has been prepared via a simple mechanochemical method. The compound could be used as precursors for the fabrication of porous carbon, which was successfully a...

The organic/inorganic hybrid material of poly[2-(dimethyl amino)-ethyl methacrylate]/polyhedral oligomeric silsesquioxane (POSS–PDMAEMA) was synthesized via a thiol-Michael addition reaction. The structures of POSS–PDMAEMA and its self-assembly in aqueous solution were confirmed by 1H-NMR, TEM, DLS, UV–Vis and fluorescence spectrum. In aqueous solutions, POSS–PDMAEMA could self-assemble into micelles and its critical micelle concentration was 12.4 mg/L. POSS–PDMAEMA micelles can adsorb dyes efficiently, it could adsorb methyl red at a concentration of 10–100 mg/L and dithizone at a concentration of 20–100 mg/L, and could remove 98% methyl red and 90% dithizone within 30 s. Due to the good temperature and pH responsiveness, POSS–PDMAEMA micelles could release organic dye absorbed into the organic solution again when the solution was heated to 40 °C or pH value of the solution was adjusted to 4.0. It suggested that POSS–PDMAEMA can be utilized as an interesting “smart” materials for absorption of organic dyes.

In this paper, chromogenic and fluorescent indicators have been prepared that can be used to detect Hg2+ in aqueous solutions. Through amide condensation reaction and primary amine-aldehyde reaction, sulfur containing thiophene group was connected to rhodamine B with diethylene triamine as bridge molecule, and rhodamine B-diethylene triamine sulfide was prepared and characterized. The prepared indicator can accurately detect Hg2+ in the environment without being interfered by other common metal ions such as ions of Na+, K+, Mg2+, Zn2+, Fe3+, Cu2+, Zn2+ and Cr3+. As the concentration of Hg2+ increases, the UV–vis absorbance at 560 nm grows. According to the Benesi-Hildebrand equation, combined with the UV–vis characterization, the stoichiometry between Hg2+ and the prepared indicator proved to be 1:1. The detection limit of detection of Hg2+ was equal to 1.95 × 10−7 mol/L, and the response of the solution turned to red after adding the indicator can be displayed within 2 min. This indicator applies to weakly acidic to neutral environments.

A colorimetric and fluorescent indicator based on cinnamamide group-containing rhodamine derivative was synthesized for the detection of Hg2+. The rhodamine B and cinnamamide were connected via ethylenediamine as a bridging molecule through a condensation reaction to obtain a colorimetric and fluorescent indicator for the detection of Hg2+ in H2O-EtOH (4:1, v/v). The indicator was excellent in the selectivity of Hg2+ and was almost unaffected by other common ions such as Na+, K+, Mg2+, Fe3+, Cu2+, Zn2+, Cr3+. The Hg2+-containing aqueous solution turned from colorless to red within 7 min after the addition of the indicator, and had an absorption peak at 564 nm in UV-vis, which implies a significant colorimetric phenomenon. Their characteristic peaks varied with the Hg2+ content, and they reached a linear relationship at low concentrations. The binding stoichiometry proved to be 1:1. The lowest detection limit was 4.1 × 10−7 mol/L, ranging from acidic to neutral.

In this paper, a new kind of colorimetric chemsensor aiming at detecting Cr3+ has been synthesized, and it is based on the “Off-On” effect of a rhodamine derivative. Comparing with other metal irons (Na+, K+, Ni2+, Hg2+, Fe3+, Mn2+, Co2+, Cd2+, Cu2+, Pb2+, Zn2+, Mg2+, Ba2+, Ag+, Fe2+, Ce3+), the chemsensor has a quick and accurate response to Cr3+ in H2O-EtOH solution (4/1, v/v). There is an obvious change in color, from colorless to bright pink when Cr3+ is detected. According to the fitting curve based on Benesi-Hildebrand equation and working curve of absorption strength in UV-vis spectrum, the binding pattern of Cr3+ and the rhodamine derivative follows a 1:1 stoichiometry. The chemsensor shows great potential in monitoring Cr3+ in the aqueous medium with high efficiency, which is supposed to complete the recognition in the minimum as 5.2 × 10−7 mol/L within 5 min.

Fe2O3/ordered mesoporous carbons (OMCs) have been synthesized by a facile one-pot hydrothermal method via self-assembly process. The combination of OMCs and anchored Fe2O3 nanoparticles shows a synergistic effect which results in a kind of anode materials with enhanced electrochemical performance for lithium ion batteries. OMCs with highly porous mesostructure and good conductivity not only alleviate the problem of volume variation and agglomeration of Fe2O3, but shorten the diffusion pathway of Li+ ions, which efficiently overcomes the problem of rapid capacity loss of iron oxide. Moreover, appropriate loading amount of Fe2O3 nanoparticles is believed to be a key factor to enhance the capacity of anode materials. The materials deliver an excellent reversible capacity of 789 mAh g−1 at a current density of 100 mA g−1 after 120 cycles.

In this work, Eu2O3/Au/SnO2 ternary nanofibers were prepared via a synergetic approach including electrospinning and calcination. The sensor based on Eu2O3/Au/SnO2 nanofibers exhibited a remarkable response (~65) to 100 ppm acetone at a relatively low operating temperature (200 °C), furthermore, the fast response-recovery kinetics and selective acetone detection had been observed simultaneously. The enhancement of acetone sensing properties can be attributed to the construction of Eu2O3/SnO2 heterostructures and the chemical sensitization of Au nanocatalysts, suggesting a pathway to develop high-efficient acetone sensors for health security.

Metal doping MnO2 has better electrochemical performance than pure MnO2. We have demonstrated a facile approach for synthesizing Mg-doped MnO2@ carbon cloth via a typical hydrothermal reaction. The intercalation of Mg2+ rapidly increases the operating window to 1.2 V. Compared to other metal ions (Co2+, Fe3+, Bi2+, Al3+, Cr2+) doping, Mg2+ doping further increases the lattice defects of MnO2, achieving more vacancies, and effectively improving the performance of MnO2. As a flexible symmetric solid supercapacitor (FSSSC), the voltage window can be extended to 2.2 V, and the energy density of FSSSC reaches 2.06 mW h/cm3 at 43.94 mW/cm3. The device can illuminate a 2.2 V LED successfully, showing its huge actual application value.

Ultrahigh specific capacity silicon is considered as a potential anode candidate for lithium-ion batteries (LIBs). In order to reduce the influence of the large volume expansion and poor conductivity of silicon, a few silicon nanoparticles are now used in commercial anodes, which increases costs and weakens the overall specific capacity. Here, we used low-cost aluminum–silicon alloys as raw materials to obtain porous silicon (pSi) particles by simple chemical etching. Then, Ag doped porous silicon/graphite (Ag-pSi/G) composite was prepared by depositing ultrafine Ag nanoparticles and mixing low-quality graphite. The large specific surface area, Ag nanoparticles and graphite provide multiple electron transport pathways in Ag-pSi/G, so they greatly increase the conductivity of the Ag-pSi/G and effectively reduce its volume expansion. The Ag-pSi/G composite shows high initial charging capacity (3313 mAh g−1 at 0.1 A g−1) and initial coulombic efficiency (82.2%), and stable reversible specific capacity of 770 mAh g−1 over 300 cycles at 1 A g−1. This simple and scalable preparation process provides a new thought for the broad application of micron silicon materials in the high-performance LIBs.

Triphosphonic acid modified multi-walled carbon nanotubes (TPA-MWCNTs) have been developed in a facile method and then characterized and used for gold ion adsorption. The adsorption behaviors of TPA-MWCNTs for Au(III), including the effect of pH, adsorption isotherm, adsorption kinetics, adsorption thermodynamics, and regeneration properties have been investigated, and the maximum adsorption capacity of TPA-MWCNTs obtained from the Langmuir isotherm is 980.39 mg/g at 35 °C. Moreover, the adsorption process optimization has been conducted by using response surface methodology (RSM) and the analysis of variance (ANOVA). Therefore, TPA-MWCNTs can be used as an efficient adsorbent in wastewater treatment and gold uptake.

Zinc oxide (ZnO) microstructures were successfully prepared by hydrothermal synthesis with PEG4000 at 120°C for 24 h. The crystalline phase and morphology of ZnO microstructures were characterised by X-ray diffraction and scanning electron microscopy. The results show that the rod-like, flower-like and dumbbell-shaped ZnO microstructures can be easily controlled by varying the amount of PEG4000. The photoluminescence spectra of ZnO microstructures with different morphology at room temperature show four emission peaks at about 362, 389, 421 and 487 nm. The photocatalytic activities of ZnO microstructures are evaluated by degradation of methylene blue (MB) under ultraviolet light irradiation, and the degradation rates of MB with rod-like, flower-like and dumbbell-shaped ZnO microstructures reached 94.8, 95.4 and 70.9%, respectively.

In this paper, by using a self-made hydrogen-containing polymethylhydrogensiloxane having a hydrogen content of 0.20%, a polyether of F-6 and α-olefin having a carbon chain length of even numbers in 6–18 as main raw materials, polyether and long-chain alkyl co-modified polydimethylsiloxane having different molecular structures were successfully prepared via hydrosilylation reactions. 1H-NMR, TGA, DLS, fluorescence spectroscopy and surface tension measurements were used to characterize their structures and properties. The results shows that when the molar ratio of polyether to α-olefin is 5:1, an emulsion type anti-foaming agent with polyether and long-chain alkyl co-modified polydimethylsiloxane as active ingredient was successfully prepared, it basically maintains 90% quality at 300 °C, indicating good heat resistance, and the critical micelle concentration (CMC) of polyether and long-chain alkyl co-modified polydimethylsiloxane is 8.55 mg/L. The surfactant has good dilution stability compared to other small molecule. When the hydrophilic-lipophilic balance (HLB) is equal to 10, the compound emulsifier is made of Span 80 and Tween 80, the emulsification method is a phase inversion method, and the obtained emulsion has the smallest particle size and an average particle diameter of 134.4 nm, the emulsion shows good stability and uniformity, and the particle size distribution is narrow. In summary, the polyether and long-chain alkyl co-modified polydimethylsiloxane synthesized in this work have potential applications in the fields of anti-foaming agent.

Controlling micropore size is the core for synthesizing highly efficient adsorbents for gas adsorption and separation engineering. Porous carbon prepared by traditional methods usually lacks competitiveness due to the random micropore size or complex process. Herein, we report a novel strategy for synthesizing nitrogen doped carbons nanosheets (Cu-NDPCs) with unimodal ultra-micropore based on the metal-organic covalency and the anion regulated in situ copper template. The thickness of single Cu-NDPCs is about 4.2 nm. In the presence of Cl−, the porosity of Cu-NDPCs can be tuned at 4.1–4.8 A by adjusting the pyrolysis temperature. Among them, Cu-NDPC-800 has unique carbon nanosheets networks structure, ultrahigh surface area (2150 m2 g−1), large micropore volume (0.92 cm3 g−1) and abundant surface N doping (5.33%). As an adsorbent, it exhibits superhigh C2H2, C2H6, C3H8 and CO2 uptakes (6.7, 7.0, 11.4 and 4.4 mmol g−1) and corresponding x/CH4 or CO2/N2 IAST selectivities (12.9, 17.8, 468.6, 4.3 and 17.1) under ambient conditions. Meanwhile, the Cu-NDPC-800 possesses excellent cyclic stability.

Cheap and excellent conductive substrates with large and manipulated geometric area have become an indispensable research object for non-self-supporting OER electrode materials to achieve the practical application. In this study, low-crystallinity 2D morphology iron hydrogen phosphate material (FPO3) with thickness of 12–16 nm is obtained by an easy polyol refluxing method. Its overpotential drop-casted on nickel foam (FPO3/NF) for OER is just 309 mV at the current density of 10 mA cm−2. Through the detailed comparative analysis, its number and the intrinsic activity of active sites for OER effectively enhanced because of the two-dimensional morphology, the low crystallinity, the excellent redox activity of iron, and the more beneficial synergy between NF and FPO3. Those results also indicate that using NF as the substrate is a high-efficiency method to realize the practical application of non-self-supporting electromaterials by a simple drop-casted treatment.

The development of highly efficient and robust bifunctional oxygen electrocatalysts is of great importance for optimizing the performance of rechargeable Zn-air batteries. In this study, Co Ni phosphides encapsulated in N, P co-doped carbon (CoNiP/PNC) were prepared by a simple one-step pyrolysis method. The obtained catalyst exhibited outstanding oxygen reduction and oxygen evolution reaction (ORR and OER) activities in alkaline media. It exhibited a positive half-wave potential of 0.84 V versus the reversible hydrogen electrode for ORR, as well as a low overpotential of 470 mV to achieve 10 mA cm−2 for OER, comparable with the benchmark Pt/C and IrO2 catalysts. Furthermore, the rechargeable Zn-air battery was fabricated, which showed a high specific capacity of 729.3 mAh gZn-1, a high peak power density of 171.0 mW cm−2, and good stability. It reveals that the interplay between heteroatom-doped carbon layers and Co Ni phase leads to the high ORR activity, and the in-situ formed bimetallic hydroxides/oxides contribute to the great OER performance. This work would inspire the future development of bifunctional electrocatalysts towards electrocatalysis in energy conversion and storage fields.

A new colorimetric “off-on” chemosensor based on rhodamine derivative bearing thiophene group has been synthesized. The chemosensor shows an excellent sensitivity and selectivity for Cu2+ over competing metal ions (Pb2+, Hg2+, Fe3+, Fe2+, Zn2+ Cd2+, Mn2+, Ba2+, Ag+ and Cr3+) in H2O-EtOH solution (1/4, v/v). A distinctive peak at 561 nm appears in the UV–vis absorption upon the addition of Cu2+ in the rhodamine derivative solution and an obvious color change to be pink from colorless. The interaction of Cu2+ and the chemosensor are proven to adopt a 1:1 binding stoichiometry, and the recognition process is expected to be completed within 1 min. With a detection limit of 1.7 × 10−7 mol/L, the chemosensor shows great potential to monitor Cu2+ in environmental analysis systems.

The temperature and pH dual-responsive polyhedral oligomeric silsesquioxane/poly[2-(dimethylamino)-ethyl methacrylate]-b-poly(N-isopropylacrylamide) hybrid materials (POSS/PDMAEMA-b-PNIPAM) were synthesized via combination of thiol-ene click chemistry and reversible addition fragmentation chain transfer polymerization. Their structures and self-assembly behaviors were characterized via 1H NMR, TEM, UV–vis and DLS measurements. POSS/PDMAEMA-b-PNIPAM could self-assemble into thermo- and pH-sensitive micelles with the POSS heads forming as a core and the PDMAEMA-b-PNIPAM chains as a corona. In vitro drug release behavior of POSS/PDMAEMA-b-PNIPAM micelles loading camptothecin indicated that the rate of drug release could be effectively controlled by altering the temperature and pH values of the environment. As 80% of the camptothecin drug was released at pH 5.5 or temperature of 45 °C within 35 h, the excellent thermo- and pH-response ability of POSS/PDMAME-b-PNIPAM micelles makes them desirable candidates for controlled drug delivery systems.

The goals of this study were to prepare activated biochar-loaded nano zero-valent iron (A-BC-NZVI) and implemented to remove heavy metal uranium (U(VI)) in sewage water. The A-BC-NZVI composite was successfully synthesized by aqueous phase reduction using biomass longan shell as carbon source under N2 at 800 °C. The influence of solution pH, A-BC-NZVI dosage, temperature, time and U(VI) concentration on U(VI) remediation via A-BC-NZVI were investigated. The batch sorption experiments reveal that the sorption capacity of U(VI) decreases from pH 7 to 10, and the adsorption kinetic experiments of pseudo-first-order, pseudo-second-order and reduction kinetics were conducted, pseudo-second-order kinetic model was well fitted through the correlation coefficient (R2). At pH 6.0, the maximum U(VI) adsorption amount of Langmuir model was calculated to be 331.13 mg/g, and the thermodynamic constants manifested that U(VI) removal by A-BC-NZVI is an endothermic and spontaneous system. XPS analysis displayed that A-BC-NZVI has two effects on U(VI), including adsorption and reduction. The results proved that A-BC-NZVI is considered highly desirable material on remediation of U(VI) from polluted groundwater.

Carbon/graphite carbon nitride (C/CN-T-x) hybrid composites with high photocatalytic activities under visible light irradiation were synthesized by an in-situ hard template method using the partially formaldehyde-modified dicyandiamide (PFMD) and tetraethyl orthosilicate (TEOS) as the precursors and template, respectively. The structures of the as-prepared composites were characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), elemental analysis, nitrogen adsorption-desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The composite prepared under the optimal conditions exhibits the large surface area of 174 m2･g−1 and high photocatalytic activity for the degradation of methylene blue (MB) under visible light irradiation. The significant improvement in photocatalytic activity of the composite, as compared with the pure graphite carbon nitride (CN), is attributed to the large surface area, strong dye adsorption ability and enhanced separation efficiency of photogenerated electron-hole pairs.

MnO2 nanosheets were prepared by hydrothermal deposition method, and supported on biomass-derived crosslinked carbon nanosheets to form a composite material (MnO2@R). First, rambutan peels were synthesized into porous carbon by pyrolysis and activation, and then MnO2 was fixed on the carbon nanosheets by hydrothermal deposition method. The MnO2@R composite material and nitrogen-doped porous carbon were assembled into an asymmetric supercapacitor. Among them, MnO2@R composite material and nitrogen-doped rambutan peel-derived porous carbon were used as positive electrode and negative electrode. Moreover, the asymmetric supercapacitor has excellent cycle stability. After 5000 cycles under 0.5 A g−1, its capacitance loss is only 12%. The asymmetric supercapacitors found in these studies have excellent energy and power density characteristics, which opens up application prospects for biomass carbon-derived composite materials.

Nearly inexhaustible sodium sources on earth make sodium ion batteries (SIBs) the best candidate for large-scale energy storage. However, the main obstacles faced by SIBs are the low rate performance and poor cycle stability caused by the large size of Na+ ions. Herein, a universal strategy for synthesizing amorphous metals encapsulated into amorphous B, N co-doped carbon (a-M@a-BCN; M = Co, Ni, Mn) nanotubes by metal cation-assisted carbonization is explored. The methodology allows tailoring the structures (e.g., length, wall thickness, and metals doping) of a-M@a-BCN nannotubes at the molecular level. Furthermore, the amorphous metal sulfide encapsulated into a-BCN (a-MSx @a-BCN; MSx : CoS, Ni3 S2 , MnS) nanotubes are obtained by one-step sulfidation process. The a-M@a-BCN and a-MSx @a-BCN possess the larger interlayer spacing (0.40 nm) amorphous carbon nanotube rich in heteroatoms active sites, making them exhibit excellent Na+ ions diffusion kinetics and capacitive storage behavior. As SIBs anodes, they show high capacity, excellent rate performance, and long cycle stability.

A new polymer namely poly (N-(3-aminopropyl) methacrylamide)-b-poly(N-isopropylacrylamide) (PAPMA-b-PNIPAM) was made for pH-triggered drug delivery by means of aqueous reversible addition-fragmentation chain transfer (RAFT) polymerization. PAPMA-b-PNIPAM was hydrophilic at 25 °C, and micelles were formed at 39 °C. The PAPMA chain was crosslinked with terephthaldicarboxaldehyde at pH = 9.0 and shell cross-linking (SCL) micelles were prepared. The sizes of the SCL micelles were 45~65 nm which can be reversible dissociated under acidic conditions. The formation of temperature-responsive SCL micelles and their cleavage behaviours were characterized.

Sn/carbon nanofibers with well dispersed Sn nanoparticles embedded in carbon nanofibers were fabricated by an electrospinning process. A SnO2 sol was used as the Sn precursor in order to improve the compatibility of tin/carbon composites and prevent Sn nanoparticles from severe agglomeration upon thermal treatment. When evaluated as a binder-free anode for lithium ion batteries, the Sn/carbon nanofibers deliver a high specific capacity of 583 mA h g−1 after 100 cycles and good cycling performance with coulombic efficiency up to 99%. The high lithium storage capability is mainly attributed to the optimized structure features including the well dispersed tin nanoparticles, high porosity, and the cushion effect of the carbon nanofibers.

Carbon-supported SnO2 nanowire arrays were synthesized by a facile strategy using self-assembled mesoporous carbon as template followed by partial removal of the carbon. The as-obtained materials were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and nitrogen adsorption. The resulting products possess a large specific surface area due to the free interspaces between the nanowires. When evaluated as anode materials for lithium-ion batteries, the carbon-supported SnO2 nanowires can deliver large reversible capabilities with excellent cycling performance on account of the mesoporous carbon matrix, which can be served as a buffering layer to relax the stress, reduce the volume variation, and protect the SnO2 nanowires from severe structural degradation during the insertion-deinsertion process of lithium ions.