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Most amino acid molecules have good water solubility and are rich in functional groups, which makes them a promising derivatizing agent for cellulose. However, self-condensation of amino acids and low reaction efficiency always happen during esterification. Here, amino acid hydrochloride ([AA]Cl) is selected as raw material to synthesize cellulose amino acid ester (CAE). Based on TG-MS coupling technology, a significantly faster reaction rate of [AA]Cl compared to raw amino acid can be observed visually. CAE with the degree of substitution 0.412–0.516 is facilely synthesized under 130–170 °C for 10–50 min. Moreover, the effects of amounts of [AA]Cl agent, temperature, and time on the esterification are studied. The CAE can be well dissolved in 7 wt% NaOH aq., resulting in a 7.5 wt% dope. The rheological test of the dope demonstrated a shear-thinning behavior for Newtonian-like fluid, and a high gel temperature (41.7 °C). Further, the synthesized products show distinct antibacterial activity and the bacteriostatic reduction rate against E. coli can reach 99.5 %. This work presents a new method for cellulose esterification using amino acid hydrochlorides ([AA]Cl). [AA]Cl were well adsorbed to cotton pulp through dipping, and esterification facilely occurred by heating their mixture. No protective agent was added and self-condensation side reaction was avoided. In particular, the online TG-MS instrument visually demonstrated a significantly increased esterification rate. The result of cellulose ester showed good solubility in dilute alkaline solution and antibacterial activity. [Display omitted] • A derivatization method of cellulose using amino acid hydrochloride is presented. • TG-MS test demonstrates a significantly increased reaction rate of the method. • Rheological tests prove that modified cellulose can be dissolved in NaOH aq. • The resulted products show distinct antibacterial activity after derivatization. [ABSTRACT FROM AUTHOR]

Positively charged and non-toxic intermediate layers are highly desirable for the construction of nanofiltration membranes in the field of Mg2+/Li+ separation. Herein, we have prepared dual-electric layer nanofiltration membranes via introducing positively charged quaternized cellulose nanocrystals (Q-CNC) beyond the negatively charged polyamide skin layers. On the one hand, the strong interactions between Q-CNC and piperazine (PIP) could regulate the thickness, roughness, and residual groups of the polyamide (PA) layers, resulting in improved water flux. On the other hand, the Q-CNC has lots of positive charges which are beneficial for enhancing the rejections of negatively charged polyamide skin layers towards divalent cations since the Donnan and electrostatic effects are long-range forces. Moreover, this effect could be amplified by reducing the thickness of skin layers or decreasing the contents of residual carboxyl groups via adjusting the monomer concentrations. The obtained nanofiltration membranes possess high water flux of 51 L/m2/h/bar, and rejection for MgCl 2 of 86 %. The separation factor of Mg2+/Li+ is 29 when the Mg2+/Li+ mass ratio in the feed solution is 20:1. Moreover, the nanofiltration membrane with Q-CNC intermediate layers (QNFM) has good antibacterial properties, showing great potential in the fields of lithium extraction from salt lakes. [Display omitted] [ABSTRACT FROM AUTHOR]

Nowadays high porosity aerogels are widely applied in wastewater purification, while the fragility and unversatility of nascent cellulose aerogels limited the application in oil/water filtering separation. Here, highly compressible, elastic, superhydrophobic cellulose/poly(vinyl alcohol) (PVA) composite aerogels were fabricated via combination of chemical cross-linking, freeze drying and silanization. The obtained cellulose/PVA aerogels exhibited durable superhydrophobicity with WCA of 156.6 °, even maintaining 155.0 ° after 30 days. Synergistic effects of physical entanglement, chemical cross-linking and H-bond network between cellulose and PVA molecular chains endowed the aerogels with excellent compressibility and recoverability. The aerogels exhibited maximum compressive stress of 490.7 kPa at 90% strain, even without reduction in mechanical strength under 70% compressive strain for 10 cycles. More importantly, the strengthened aerogels exhibited remarkable separation performances for both immiscible oil/water mixtures and surfactant-stabilized water-in-oil emulsions. Fascinating permeation flux of up to 7176.3 L m−2 h−1 and total separation amount as high as 4550.6 L m−2 with separation efficiency of 98.5% for water-in-cyclohexane emulsion were harvested. Thus, this work provides a green, sustainable and mass-producible cellulose-based aerogel for high-efficiency oily wastewater remediation. [ABSTRACT FROM AUTHOR]

Mechanically twisting a yarn is a useful and important method for creating internal stress, changing macromolecular orientation, and affording interesting fiber properties, including mechanical, structural, physical and chemical properties. Bacterial cellulose (BC) nanofibers are a new type of highly crystalline bionanofibers exhibiting excellent intrinsic mechanical properties. Herein, BC macrofibers with a diameter of 0.35–0.53 mm were prepared from BC hydrogel films using a two-step technique involving drying and twisting processes. Moreover, the effects of the drying method (oven- and freeze-drying) and those of the processing steps on the morphologies, structures, and physicochemical properties of the macrofibers were investigated. Results indicated that only the wet twisting–first process affords continuous macrofibers with a compact and uniform structure. The tensile strength and elongation at break of the macrofibers were 199 MPa and 24%, respectively. Furthermore, by introducing graphene oxide (GO) to the macrofibers, a photothermal and moisture actuator was facilely constructed, which could produce a twisting motion of 0.39 rpm and an untwisting motion of 0.6 rpm. This study provides insights into methods to easily alter the properties of BC macrofibers, which is pivotal for the macrofiber's potential application in intelligent devices. [Display omitted] • The surface of T-OD macrofibers is smooth and flat, and the tensile stress can reach 199 MPa. • The GO-T-OD macrofiber can produce reversible motion under moisture and NIR light stimulation, and the rotation angle can be increased to 121°/cm in 25 s • Reversible twisting artificial muscles offer unlimited possibilities for future applications in artificial muscles and other intelligent drives. [ABSTRACT FROM AUTHOR]

Double stimuli-responsive functionalized cellulose nanocrystal-poly[2-(dimethylamino)ethyl methacrylate] (CNC- g -PDMAEMA) reinforced poly(3-hydroxybutyrate- co -3-hydroxy valerate) (PHBV) electrospun composite membranes were explored as drug delivery vehicles using tetracycline hydrochloride (TH) as a model drug. It was found that rigid CNC- g -PDMAEMA nanoparticles enhanced thermal, crystallization and hydrophilic properties of PHBV. Moreover, great improvements in fiber diameter uniformity, crystallization ability and maximum decomposition temperature (T max) could be achieved at 6 wt% CNC- g -PDMAEMA. Furthermore, by introducing stimuli-responsive CNC- g -PDMAEMA nanofillers, intelligent and long-term sustained release behavior of composite membranes could be achieved. The releasing mechanism of composite membranes based on zero order, first order, Higuchi and Korsmeyere-Peppas mathematical models was clearly demonstrated, giving effective technical guidance for practical drug delivery systems. Electrospun PHBV composites membrane with double stimuli-responsive cellulose nanocrystal tailor drug release at human physiological condition for long-term sustained drug delivery. Unlabelled Image • Functionalized cellulose nanocrystals gave double stimuli-responsive performance. • Composite membrane has intelligent drug release ability at human physiological condition. • Composite membrane shows faster drug rate at pH = 5 for potential tumor cell targeting. • Four releasing mechanism of composite membranes have been clearly demonstrated. [ABSTRACT FROM AUTHOR]

Blending of plant-based cellulose and marine-derived chitosan in micro-level has potential to make fascinating materials. However, this task is frequently hindered by the poor solubility of the polysaccharides. Here, using a green alkali/urea solvent media together with a well-designed dissolving strategy, original cellulose pulp and chitosan power were dispersed into a homogeneous solution. Driven by the intermolecular hydrogen-bond interaction, cellulose and chitosan chains were facially self-assembled into a unique 3D alloy structure. Owing to the rich interface interactions, the tensile strength and breaking elongation of the alloy film increased by 69% and 260%, respectively, when compared to a pure chitosan film. Besides, the 3D alloy films with a pore diameter of 920–1435 nm exhibited an extremely high cell viability which was higher than 95%. Additionally, accelerated wound healing rate of 95.6% reached in the presence of the alloy film after two weeks using a full-thickness wound in a rat model. Unlabelled Image • Chitosan and cellulose were co-dissolved into one green alkali/urea solvent. • Polysaccharide chains were self-assembled into 3D porous alloy films. • Abundant interface interactions led to excellent physicochemical properties. • Biocompatibility and bioactivity of the alloy result in good wound healing. [ABSTRACT FROM AUTHOR]

Nanostructured materials with designable microstructure fabricated through a facile and green method are highly desired for practical applications in nanotechnology. Herein, without using any toxic reagents, flexible cellulose aerogel nanocomposites embedded with ZnO@noble metal nanoparticles (NPs) were successfully prepared from a cellulose dope. Morphology, structure, and mechanical properties of the nanocomposite were characterized. Flower-liker ZnO particles were synthesized through cellulose mineralization and it acted as a platform for efficient photocatalytic synthesis of noble metal (Ag, Au, Ag-Au) NPs. The noble metal NPs were well dispersed in the three-dimensional (3D) cellulose skeleton, resulting in abundant "hot spots" for high Surface Enhanced Raman Scattering (SERS) signal enhancement. Using rhodamine 6 G (R6G) molecules as probe molecules, the detection limits and calculated enhancement factors approached to 10−10 M and 4.8 × 107, respectively. Particularly, the photocatalytic capabilities of noble metal-semiconductor heterostructure embedded in porous aerogel made it a self-cleaned SERS substrate. There was little sensitivity loss after recycling use for 3 times. This work presented a sustainable and cost-reduction strategy to construct sensitive SERS substrate. [Display omitted] • Cellulose aerogel embedded with ZnO@Ag/Au is facilely fabricated from a dope. • The actived celluloe chains act as mineralization template for flower-like ZnO. • Ag/Au NPs are plated to ZnO surface through a controllable photoreduction method. • 3D porous aerogel gives anchoring effect for particles and bring abundant "hot spots". • Hierarchical nanostructures achieves a flexible, sensitive and reusable SERS strips. [ABSTRACT FROM AUTHOR]

Highlights • A facile method of loading metal-organic frameworks (MOFs) onto cellulose aerogels (CA) is developed. • The equilibrium adsorption capacity of Pb2+ adsorbed by UiO-66-NH 2 @CA was 89.40 mg g−1. • The complete decomposition temperature of UiO-66-NH 2 @CA was increased by 62.1 ℃ compared with CA. • The hybrid aerogels could be recycled without secondary pollution. Abstract In the present work, we develop novel method of loading metal-organic frameworks (UiO-66 and UiO-66-NH 2) on the flexible cellulose aerogels as metal-organic frameworks@cellulose aerogels composite materials by using in situ growth procedure at room temperature. The as prepared metal-organic frameworks@cellulose aerogels composite materials were well characterized via SEM, XRD, atomic absorption spectrometer, and TG analysis, besides the adsorption of Pb2+ and Cu2+ in metal-organic frameworks@cellulose aerogels composite materials was investigated. The amount of metal ions adsorbed by metal-organic frameworks@cellulose aerogels composite materials is equal to the sum of metal-organic frameworks and cellulose aerogels, indicating that the metal-organic frameworks are not blocked after cellulose aerogels growth and still have adsorption properties. It was found that metal-organic frameworks@cellulose aerogels composite materials can be recycled to adsorb Pb2+ and Cu2+ in water after simple cleaning. The equilibrium adsorption capacity of Pb2+ adsorbed by UiO-66-NH 2 @CA was 89.40 mg g−1, and can be easily reused for more than 5 cycles without significant decrease in performance. Moreover, the maximum decomposition temperature (T max) of UiO-66-NH 2 @CA was increased by 62.1℃. This result suggested that such metal-organic frameworks@cellulose aerogels composite materials could adsorb heavy metal ions in water could by avoiding secondary pollution and show great potential in water treatment. [ABSTRACT FROM AUTHOR]

Cellulose based Ag-functionalized ZnO nanocomposite (AZC) films were prepared using a green and easy scale-up strategy. Firstly, ZnO embedded cellulose (ZC) nanocomposite was synthesized from a cellulose-NaOH/zincate/urea solution through a biomimetic approach. Secondly, Ag nanoparticles (NPs) with a mean diameter of 53.2 nm were efficiently deposited onto the surface of embedded ZnO in cellulose matrix under UV irradiation (16 w), yielding the multi-hybrid AZC film. Owing to the porous structure of cellulose substrate and its rich hydroxyl group, the NPs in the ACZ films displayed good stability. Because of the formation of Schottky barriers in the Ag-ZnO regions, the catalytic activity of ACZ films increased by 20 times when compared to that of ZC sample. Furthermore, the AZC films could completely inhibit both S. aureus and E. coli growth. This facile and eco-friendly approach is expected to pave the way for constructing multifunctional cellulose material for various niche applications. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) as catalysts for the activation of peroxymonosulfate (PMS) to remove recalcitrant organic contaminants has been well reported, however, the separation of MOFs from the solution is difficult because of their powder state, which limits their applications. In the present study, zeolitic imidazole framework (ZIF) materials, ZIF-9 and ZIF-12 were pioneered to load on cellulose aerogels, and the hybrid aerogels as metal catalysts to effectively activate PMS for Rhodamine B (RB), tetracycline hydrochloride (TC) and p-nitrophenol (PNP) degradation. The hybrid aerogels/PMS system could remove PNP about 90% in 1 h, which hard to remove from water. The pH value of the solution had no effect on the degradation process, which demonstrated that the hybrid aerogels had excellent pH tolerance. In addition, the mechanism of PNP degradation was investigated by electron paramagnetic resonance (EPR) and free radical trapping methods. The results showed that PMS could effectively activate by hybrid aerogels to produce sulfate radicals (SO 4 −), hydroxyl radicals ( OH), and revealed that SO 4 − play a key role in degradation. The most important feature of hybrid aerogels is can be easily separated from the solution. The obtained results showed that the hybrid aerogels exhibit excellent recyclability, with no significant effect on degradation. The prepared hybrid aerogels are green, environmentally friendly with high catalytic efficiency. Further, the outstanding degradation of PNP demonstrates the promising prospects of hybrid aerogels as advanced oxidation process (AOP) catalysts. [ABSTRACT FROM AUTHOR]

The low cost of adsorption treatment of heavy metal ions in water has been extensively studied. In this paper, we have demonstrated a facile method of combining two emerging materials cellulose aerogels (CA) and metal–organic frameworks (MOFs) into one highly functional aerogel to adsorption removal of heavy metal ions from water, by entrapping MOF particles into a flexible and porous CA. The resultant hybrid cellulose aerogels had a highly porous structure with zeolitic imidazolate framework-8 (ZIF-8) loadings can reach 30 wt%. The hybrid cellulose aerogels (named as ZIF-8@CA ) show good adsorption capacity for Cr(Ⅵ). The adsorption process of ZIF-8@CA is better described by pseudo-second-order kinetic model and Langmuir isotherm, with maximum monolayer adsorption capacity of 41.8 mg g −1 for Cr(Ⅵ), whose adsorption capacity has greatly improved when compared with a single CA or ZIF-8. Thus, such a flexible and durable hybrid cellulose aerogel is a very prospective material for metal ions cleanup and industrial wastewater purification. [ABSTRACT FROM AUTHOR]

This work presents a facile and practical preparation method of cellulose-based bioadsorbent modified by hyperbranched polyethyleneimine (hPEI) using glutaraldehyde cross-linking in heterogeneous system for various dyes removal. The grafting of hPEI with a large molecular structure was achieved efficiently according to the FTIR and XPS analysis. The adsorption properties of the cellulose-based bioadsorbent for anionic reactive yellow X-RG (XRG), cationic bright yellow M-7G (M7G), nonionic disperse brown S-3RL (DB 3) were explored. The kinetics curve was well fitted with pseudo-second-order model, and the equilibrium data well suited Langmuir model with maximum adsorption capacity of 571.43 mg g −1 for M7G, 581.40 mg g −1 for DB 3 and 970.87 mg g −1 for XRG. Compared with other bioadsorbents reported previously, the cellulose-based bioadsorbent could be facilely prepared and simultaneously exhibited enhanced removal for dyes. Therefore, this work will help accelerate the study of scale production of bioadsorbent for treatment of textile effluents. [ABSTRACT FROM AUTHOR]

[Display omitted] • Amphoteric cellulose microsphere (ACM) contains both carboxyl and amino groups. • ACM displayed hierarchic porous network structures and high specific surface areas. • ACM could simultaneously remove both cationic and anionic dyes. • ACM could effectively treat actual dyeing wastewater. Amphoteric cellulose porous microsphere adsorbents (ACM) with high contents of functional groups were prepared by carboxylation and amination reactions. The obtained ACM possess similar contents of carboxyl groups (1.52 mmol/g) and amino groups (1.51 mmol/g). In addition, the modified microspheres exhibited excellent mechanical properties benefiting from the dense porous structures. The ACM could simultaneously remove the cationic dye methyl orange (MO) as well as the anionic dye methylene blue (MeB) with adsorption capacities as high as 345.32 mg/g and 616.12 mg/g, respectively. Another the microspheres are also with good regeneration that the adsorption capacities still maintained more than 90 % after 8 cycles. [ABSTRACT FROM AUTHOR]

Electroless plating occupies a vital position in the fields of metal anticorrosion while accompanied by a large amount of effluent containing organophosphorus (like phytic acid) and heavy metals ions {like Cu (II) and Ni (II)}. However, it was still remaining great challenges in how to simultaneously remove these organophosphorus and heavy metal ions with simple methods. This work prepared a green, clean and efficient adsorbent amino-functionalized cellulose (AFCA) for simultaneous removal of organophosphorus and metal ions from complex wastewater. Benefitting from its abundant amino groups, AFCA can rapidly remove organophosphorus and metal ions within 10 min. The theoretical maximum adsorption capacities of AFCA could also reach as high as 89.29 mg/g, 79.37 mg/g and 178.57 mg/g, respectively. Most importantly, for the mixed system of organophosphorus and Cu (II), the removal efficiency was increased by 5.66% and 30.23% compared with the individual system, respectively. High simultaneous removal capacity of AFCA was due to the hydrogen bond and electrostatic interactions with organophosphorus and the complexation interactions between abundant amino groups and metal ions. All of these results demonstrate that AFCA has enormous potential for the treatment of actual electroless plating effluents. [Display omitted] • Green, clean and efficient adsorbent AFCA was prepared from waste cellulose. • AFCA has abundant active amino groups with a content of 2.6 mmol/g. • AFCA displayed efficient adsorption of organophosphorus, Cu (II) and Ni (II). • AFCA can simultaneous and synergistic removal of OP and Cu (II) from mixed system. [ABSTRACT FROM AUTHOR]

The discharge of effluents from surfactant manufacturers is giving rise to increasingly serious environmental problems. In order to develop the eco-friendly flocculation materials to achieve effective removal of pollutants from the surfactant effluents, the bamboo pulp cellulose from Phyllostachys heterocycla is employed as the skeleton material to synthesize an eco-friendly bamboo pulp cellulose-g-polyacrylamide (BPC-g-PAM) for flocculation. The BPC-g-PAM is used with the metal ions as the coagulant to treat the effluent from a surfactant manufacturer. The response surface methodology coupled with Box–behnken design is employed to optimize the key factors of coagulation–flocculation. The results show that the combination of Fe 3+ with BPC-g-PAM achieves the best coagulation–flocculation performance like, the fast treatment time, minimum coagulant and BPC-g-PAM dosages compared with the other two combinations of Al 3+ with BPC-g-PAM and Ca 2+ with BPC-g-PAM. Therefore, the combination of Fe 3+ with BPC-g-PAM is expected to promote its application for the pollution control in the surfactant manufacturers. [ABSTRACT FROM AUTHOR]

Abstract: This work presents a synthesis process and flocculation characteristics of an eco-friendly flocculant based on bamboo pulp cellulose (BPC) from Phyllostachys heterocycla. Ployacrylamide (PAM) was grafted onto the BPC by free-radical graft copolymerization in homogeneous aqueous solution. The optimal synthesis conditions of the bamboo pulp cellulose-graft-ployacrylamide flocculant (BPC-g-PAM) and its performance on wastewater treatments were investigated. A UV-based method was used to rapidly determine the degree of substitution (DS) of BPC. The results showed that, under the optimal synthesis conditions, the obtained BPC-g-PAM held a grafting ratio of 43.8% and DS of 1.31. Turbidity removal of the product reached 98.0% accompanying with the significant flocculation and sedimentation in target suspensions. The flocculation mechanism was explored by means of zeta potential method. For negatively charged contaminants, like kaolin clay particles, the BPC-g-PAM could remove the contaminants efficiently via bridging and charge neutralization in acidic or neutral environment. [Copyright &y& Elsevier]

[Display omitted] • Cellulose-based absorbents with the highest reported uranium uptake are achieved. • Homogeneous reactions are beneficial to grafting density and material utilization. • Excellent hydrophilicity contributes to rapid mass transfer and antifouling property. • The adsorbents could be filled into filtration columns for dynamic adsorption. • The adsorbents collect 50 mg uranium/g from simulated seawater in 24 d adsorption. Highly efficient extraction of uranium from seawater is regarded as an important guarantee for the promotion of nuclear electricity generation. Amidoxime based adsorbents are considered as the most promising materials for uranium recovery due to their high selectivity and binding capability to uranyl ions. Herein, natural celluloses with advantages of low cost, biodegradability, renewability were chosen as the raw materials. Moreover, amidoximated cellulose-based adsorbents are fabricated by two steps of homogeneous reactions including the Michael addition and amidoximation reaction. Compared with traditional surface grafting methods, both the grafting density of active adsorption sites and the utilization of raw materials could be greatly improved because of the lower steric hindrance as well as more exposed reactive sites during the homogeneous reactions. The adsorption capacity of our adsorbents can reach as high as 517.07 mg/g at pH = 7, one of the best cellulose-based adsorbents as far as we know. In addition, excellent hydrophilicity of the adsorbents, which is inherited from the natural cellulose, can endow them with enhanced mass transfer as well as resistance to marine pollutants. More importantly, the adsorption microspheres would be filled into filtration column for dynamic adsorption benefited from their aforementioned merits. The average adsorption capacity could maintain above 2.5 mg/g per day when the filtration column was exposed to simulated seawater for 24 days. All these characteristics make the amidoximated cellulose-based adsorbents potentially applicable to the uranium recovery from seawater. [ABSTRACT FROM AUTHOR]

Abstract: A new, low-cost, and eco-friendly cellulose-based superabsorbent was successfully prepared from flax yarn waste. The method used was a free-radical graft copolymerization of AA and AM onto a cellulose backbone in a homogeneous aqueous solution. APS was used as the initiator in the presence of a crosslinker, MBA. The effects of various factors on water absorbency were discussed. The factors included reaction temperature, initiator amount, monomer amount, salt solution type, and solution pH. Under the optimized conditions, the water absorbencies of the obtained superabsorbent composite were 875g/g distilled water, 490g/g natural rainwater, and 90g/g 0.9wt% aqueous NaCl solution. The product also had excellent water retention and salt resistance properties. Fourier-transform infrared spectroscopy and scanning electron microscopy were employed to examine the structure of the prepared superabsorbent. [Copyright &y& Elsevier]

Abstract: A kind of cellulose whiskers were extracted from the branch-barks of mulberry (Morus alba L.) by an alkali treatment at 130°C and subsequently a sulfuric acid hydrolysis. AFM image showed that the diameter of obtained whiskers was ranged from 20 to 40nm. The chemical compositions analysis, FT-IR, XRD results indicated that the hemicellulose and lignin were removed extensively in the cellulose whiskers, with a crystallinity of 73.4%. The TGA curves implied a two-stage thermal decomposition behavior of cellulose whisker due to the introduction of sulfated groups into the crystals in the sulfuric acid hydrolysis process. The obtained whiskers may have the potential applications in the fields of composites as a reinforcing phase, as well as in pharmaceutical and optical industries as additives. [Copyright &y& Elsevier]

• Synthesis of bimetallic silver-gold NPs was realized in a cellulose dope. • The dissolved cellulose played as reductant and support matrix for the NPs. • Structure of the NPs was facially tuned by adjusting the feeding operations. • Correlation of bioactivity with nanostructure of the NPs was investigated. • Flexible cellulose decorated with the NPs endowed its efficient SERS activity. Introducing functional metal nanoparticles (NPs) into flexible substrate is being increasingly attempted to expand their application. Here, we extend the synthesis of cellulose to its unmodified dope achieving freestanding nanocomposite decorated with bimetallic Ag-Au NPs through the one pot reaction. In the procedure, cellulose chain not only acts as a reducing agent but also a biocompatible support for NPs with a mean size of 7.9–9.7 nm. Meanwhile, changing the addition order of Ag+ and AuCl 4 − generated different atom arrangement in the bimetallic NPs. Moreover, the correlation of bioactivity to NP atom arrangement was studied. The result revealed that the nanocomposite containing NPs with an ultrathin Ag-rich outermost shell around an Au-rich core showed better bactericidal ability while lower cytotoxicity. In addition, the nanocomposite exhibited a sensitive SERS property for determination of R6G with a high enhancement factor of 108. [ABSTRACT FROM AUTHOR]

Robust, metal-free, macroscopic 3D porous CN/CE hybrid photocatalyst was fabricated by the co-assembly of g-C 3 N 4 and cellulose substrate, in which such an interconnected porous network facilitates mass transport, strong adsorption and multireflection of incident light. Consequently, the CN/CE hybrid photocatalyst exhibited both an excellent adsorption capacity and improved photocatalytic activity toward methylene blue degradation with degradation rate of 99.8%. • Robust, metal-free, 3D porous g-C 3 N 4 /cellulose hybrid photocatalyst was fabricated. • Highly porous network facilitates mass transport, adsorption and light multireflection. • Syncretic interface between g-C 3 N 4 and cellulose increases photoelectrons transfer. • Methylene blue removal ratio over the CN/CE hybrid photocatalyst reaches up to 99.8%. • The CN/CE hybrid photocatalyst exhibits mechanical stability and high reusability. Robust, metal-free, macroscopic 3D porous g-C 3 N 4 /cellulose (CN/CE) hybrid photocatalyst was successfully fabricated by the co-assembly of g-C 3 N 4 and cellulose substrate. The morphology, structure, mechanical property, optical and electrochemical performances, and photocatalytic activity of the CN/CE were investigated in detail. The obtained CN/CE hybrid photocatalyst possessed homogeneous 3D interconnected network structure, excellent mechanical strength and considerable recyclability. Also, the CN/CE hybrid photocatalyst exhibited both an excellent adsorption capacity and improved photocatalytic activity toward methylene blue (MB) degradation with degradation rate of 99.8%, much higher than that of pure g-C 3 N 4 (54.2%). The enhanced photocatalytic performance of CN/CE derived from the synergistic effects of homogeneous 3D interconnected network structure and syncretic interfaces between g-C 3 N 4 and cellulose, facilitating mass transport, light absorption and reactant adsorption, as well as the transfer of the photogenerated electrons. Moreover, the CN/CE hybrid photocatalyst indicated a high reusability and stability without significant reduction in its efficiency with nearly 96% of MB degradation after four cycles. This work not only demonstrated the importance of homogeneous interconnected network structure to prepare highly effective photocatalyst, but also provided a new insight into the approach for design and utilization of stable and recyclable metal-free photocatalyst for visible light derived contaminant degradation. [ABSTRACT FROM AUTHOR]