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•A novel strategy is proposed to prepare cellulose-based adsorbents for protein.•The adsorbents show high specific surface area and improved mechanical property.•The modified ...adsorbents exhibit excellent performance for protein separation.
Cellulose derived adsorbent has attracted increasing interest owing to its low production cost, easy modification and biocompatibility. However, the intrinsic deficiencies of cellulose, including weak mechanical property and high crystallinity, seriously compromise the separation efficiency. To overcome these issues, a pre-cross-linking method together with the hybridization of agarose is proposed for constructing high-strength and low-crystallinity cellulose-based microspheres. Through the pre-crosslinking method, the crosslinking reaction between polysaccharides and epichlorohydrin is homogeneous, which endows the microspheres with high mechanical strength for better recyclability. Meanwhile, the introduction of agarose disorders the ordered aggregation of cellulose, by which more amorphous regions are created for high specific surface area. Finally, after being modified with 2-diethylethylamine hydrochloride, the proposed anionic adsorbent showed both high maximum adsorption capacities (BSA: 307.6 mg g−1; BHb: 161.4 mg g−1). Together with excellent mechanical stability, the proposed cellulose/agarose composite microspheres have a great potential in protein separation.
Abstract
Coherent interaction between matter and light field induces both optical Stark effect and Bloch–Siegert shift. Observing the latter has been historically challenging, because it is weak and ...is often accompanied by a much stronger Stark shift. Herein, by controlling the light helicity, we can largely restrict these two effects to different spin-transitions in CsPbI
3
perovskite quantum dots, achieving room-temperature Bloch–Siegert shift as strong as 4 meV with near-infrared pulses. The ratio between the Bloch–Siegert and optical Stark shifts is however systematically higher than the prediction by the non-interacting, quasi-particle model. With a model that explicitly accounts for excitonic effects, we quantitatively reproduce the experimental observations. This model depicts a unified physical picture of the optical Stark effect, biexcitonic optical Stark effect and Bloch–Siegert shift in low-dimensional materials displaying strong many-body interactions, forming the basis for the implementation of these effects to information processing, optical modulation and Floquet engineering.
In this paper, we report a simple and reliable hydrothermal synthesis strategy to prepare high-performance energy storage materials. Herein, polyvinylpyrrolidone (PVP) was added to obtain spherical ...MoS2 composite wheat straw cellulose carbon material (MoS2 @WSCC-S), and ammonium persulfate (APS) was further added under acidic conditions to obtain 3D nanoflower-like MoS2 grown on wheat straw cellulose carbon (MoS2 @WSCC-F). These results unequivocally demonstrate that the presence of oxygen-containing groups and the pH of the solution are key factors enabling the formation of flower-like structures, with MoS2 uniformly decorated on the wheat straw cellulose carbon. Mo at the edge of MoS2, C in PVP molecules, and oxygen-containing functional groups released by APS are directly coupled with wheat straw cellulose carbon (C-O-Mo bond). The interfacial interaction of the C-O-Mo bond can enhance the electron transport rate and structural stability of the MoS2 @WSCC-F electrode. The wheat straw cellulose carbon enhances the electrical conductivity of the composite and maintain structural integrity, and at the same time, it can not only serve as a substrate for uniformly dispersing active MoS2, but also serve as a buffer to accommodate volume changes during cycling. As a negative electrode material for lithium-ion batteries, the obtained MoS2 @WSCC-F has a stable charge-discharge capacity of 1056.3 mAh g−1 after 300 cycles at a 1 C rate, a first-cycle Coulombic efficiency of 77 %, and a capacity retention rate of 80.4 %.
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•Nanoflower-like MoS2 has grown on wheat straw cellulose through one-step hydrothermal method.•This composite displayed stable electrochemical performance when used as anode for LIBs.•The few-layered MoS2 nanosheets can provide shorter ion diffusion paths and improved Li+ diffusion mobility.•The charge-discharge capacity of MoS2 @C finally stabilizes at 1056.3 mAh g−1 after 300 cycles at a 1 C rate.
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Metal-organic frameworks (MOFs) have the advantages of controllable chemical properties, rich pore structures and reaction sites and are expected to be high-performance anode ...materials for the next generation of potassium-ion batteries (PIBs). However, due to the large radius of potassium ions, the pure MOF crystal structure is prone to collapse during ion insertion and processing, so its electrochemical performance is quite limited. In this work, a hollow carbon sphere-supported MOF-derived Co/CoSe heterojunction anode material for potassium-ion batteries was developed by a hydrothermal method. The anode has high potassium storage capacity (461.9 mA h/g after 200 cycles at 1 A/g), excellent cycling stability and superior rate performance. It is worth noting that the potassium ion storage capacity of the anode material shows a gradual upward trend with the charge–discharge cycle, which is 145.9 mA h/g after 3000 cycles at a current density of 10 A/g. This work demonstrates that MOF-derived CoSe anodes with high capacity and low cost may be promising candidates for the introduction of potassium ion storage.
ZnO is considered to be the next generation lithium-ion battery anode material due to its high theoretical capacity, low potential, abundant resources and low toxicity. However, high volume expansion ...during charge–discharge process makes ZnO powdered and agglomerated easily. In the work, we fabricate a porous carbon skeleton by using rice husk (RH) lignin, and the ZnO nanoparticles are supported on the skeleton uniformly. Its unique structure provides excellent stability and electrical conductivity. RH as a carbon source will improve the utilization rate of biomass materials in the refining process. The samples were characterised by XRD, Raman, TG, SEM and transmission electron microscopy, and the materials presented a promising Li storage properties and electrochemical performance with a discharge capacity of 898.1 mAh g
−1
at 0.2C after 110 cycles, which is very close to the theoretical specific capacity of zinc oxide (978 mAh g
−1
).
In this paper, sunflower seed husks were used as raw materials to prepare porous biomass carbon through physical carbonization and chemical activation. Calcium chloride and pyromellitic acid were ...used as activators and processing assistant. The influences of activation temperature and processing additives on the activation mechanism of CaCl
2
were analyzed. The results showed that activation temperature and processing aids act on the two competing mechanisms of micropore formation and pore expansion, respectively. The average pore diameter of the resulting sample was 9.75 nm, and the specific surface area was 404.215 m
2
g
−1
. The sample was circulated 100 cycles at 0.2 C. The specific flow was 1100 mAh g
−1
in the change rate test. The discharge specific capacity was 590 mAh g
−1
after 450 cycles at 2 C rate. The structure of the sample collapsed after 250 cycles at 5 C, and the specific discharge capacity dropped to 390 mAh g
−1
after 350 cycles.
Ternary chalcopyrite CuInS2 quantum dots (QDs) have been extensively studied in recent years as an alternative to conventional QDs for solar energy conversion applications. However, compared with the ...well-established photophysics in prototypical CdSe QDs, much less is known about the excited properties of CuInS2 QDs. In this work, using ultrafast spectroscopy, we showed that both conduction band (CB) edge electrons and copper vacancy (VCu) localized holes were susceptible to surface trappings in CuInS2 QDs. These trap states could be effectively passivated by forming quasi-type II CuInS2/CdS core/shell QDs, leading to a single-exciton (with electrons delocalized among CuInS2/CdS CB and holes localized in VCu) half lifetime of as long as 450 ns. Because of reduced electron-hole overlap in quasi-type II QDs, Auger recombination of multiple excitons was also suppressed and the bi-exciton lifetime was prolonged to 42 ps in CuInS2/CdS QDs from 10 ps in CuInS2 QDs. These demonstrated advantages, including passivated trap states, long single and multiple exciton lifetimes, suggest that quasi-type II CuInS2/CdS QDs are promising materials for photovoltaic and photocatalytic applications.
In this research, we separated cellulose from wheat straw by chemical treatment, and then coated it around the ultrafine nano-size SnO2 by a hydrothermal method to form a unique carbon coating. The ...elastic feature of carbon supports could provide a cushion effect against the volume strain and increase the electrical conductivity of the nanocomposite material. Additionally, two non-metal elements, nitrogen and sulfur have been added to the composite to form chemical bonds with the external amorphous carbon of composite material, which leading to a further improved electrochemical performance. The final synthesized composite material was named SnO2@WSC, when used as an anode for lithium-ion batteries, the specific discharge capacity of SnO2@WSC in the first cycle reached 1750 mA hg−1. And after 200 cycles, the discharge specific capacity reached 1130 mA hg−1 and 1100 mA hg−1 at 0.2C and 1C current respectively, which exhibits superior cycle stability.
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•Jute fiber is used as precursor to prepare micro-mesoporous carbon anode materials for lithium ion battery.•This biomass-derived porous carbon possesses a high specific surface area.•This biomass-derived carbon shows an outstanding cycle stability and specific capacity.
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