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Water-in-oil (W/O) Pickering emulsions have wide applications in the food industries. However, the existing W/O Pickering particles have disadvantages such as lack of bioactivity and poor stability. In this study, naturally occurring bioactive oleanolic acid (OA) was used as a novel emulsifier for W/O emulsions. Results revealed that rod-like OA could formulate into spherical nanoparticles by self-assembly, and then be anchored onto the oil-water interface to stabilize the emulsions. Besides, both OA concentration and internal water fraction (φ) had significant effect on the properties of emulsions. Furthermore, the resulted emulsions exhibited potential application as carriers for epigallocatechin-3-gallate (EGCG), which significantly improved its UV and thermal stability. Meanwhile, it could effectively protect EGCG from gastric digestion, and controlled release in the intestine. This work demonstrated the successful application of OA as a stabilizer for W/O emulsions, and provided valuable insight into its potential as delivery system for hydrophilic instable compounds., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The combination of photothermal treatment and chemodynamic therapy has attracted extensive attention for improving therapeutic effects and compensating the insufficiency of monotherapy. In this work, a copper-metal organic framework (Cu-BTC) was used to augment the photothermal effect of polydopamine (PDA) and endow it with a chemodynamic ability by constructing a Cu-BTC@PDA nanocomposite. Density functional theory calculations revealed that the plasmonic vibrations formed by the d-d transition of Cu at the Fermi level in Cu-BTC@PDA could enhance the photothermal performance of PDA. In addition, more Cu 2+ released from Cu-BTC@PDA in the acidic microenvironment of the tumor was then reduced to Cu + by glutathione (GSH) and further catalyzed H 2 O 2 to generate more toxic hydroxyl radical (•OH), which synergized with photothermal treatment for melanoma therapy. Furthermore, Cu-BTC@PDA could quickly and effectively kill bacteria under the action of PTT, and the sustained release of Cu ions could contribute to the long-term and stable bacteriostatic ability of the material. This sustained release of Cu ions could also promote the cell migration and angiogenesis, and upregulate the expression of COL-, TGF-, and VEGF-related genes to accelerate wound healing. This multifunctional nanomaterial has potential application in the treatment of melanoma and repair of wounds. STATEMENT OF SIGNIFICANCE: We constructed a multifunctional nanoplatform (Cu-BTC@PDA) by two steps. This nanoplatform can not only perform cascade catalysis in the tumor microenvironment to generate more toxic hydroxyl radical (•OH), but also synergize with photothermal treatment for melanoma therapy. Additionally, Cu-BTC@PDA possesses enhanced photothermal performance through the plasmonic vibrations formed by the d-d transition of Cu at the Fermi level in Cu-BTC@PDA, which is revealed by DFT calculations. And Cu-BTC@PDA shows good antitumor, antibacterial, and wound healing properties in vivo and in vitro. Such a multifunctional nanomaterial has potential application in the treatment of melanoma and repair of wounds., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest., (Copyright © 2023 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Phase change materials (PCM) are promising for thermal regulation and energy storage, but suffer from the deformation and leakage of capsules. Herein, inspired by cellulose nanocrystal (CNC), xylan nanocrystal (XNC) with a dimension of 25-60 nm was successfully prepared through oxalic acid hydrolysis of high-crystalline xylan as raw materials via a top-down approach. With the introduction of hydrophobic groups, compared to XNC, succinylated XNC showed more remarkable emulsifying property over 7 days of storage at room temperature. Microencapsulated PCM composite consisting of sodium alginate (SA) as "matrix" and succinylated xylan nanocrystal (XNC) stabilized paraffin-based Pickering capsule (PCM beads) as "core" was facilely fabricated. PCM composite with the latent heat of 105.59 J·g -1 showed excellent thermoregulating performance. Our work suggests a new pathway toward sustainability of hemicelluloses in the application of food emulsion and thermal energy management., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Selenium nanoparticles (SeNPs) have attracted widespread attention, but the poor water dispersibility restricted their applications seriously. Herein, Usnea longissima lichenan decorated selenium nanoparticles (L-SeNPs) were constructed. The formation, morphology, particle size, stability, physicochemical characteristics, and stabilization mechanism of L-SeNPs were investigated via TEM, SEM, AFM, EDX, DLS, UV-Vis, FT-IR, XPS, and XRD. The results indicated that the L-SeNPs displayed orange-red, amorphous, zero-valent, and uniform spherical nanoparticles with an average diameter of 96 nm. Due to the formation of CO⋯Se bonds or the hydrogen bonding interaction (OH⋯Se) between SeNPs and lichenan, L-SeNPs exhibited better heating and storage stability, which kept stable for more than one month at 25 °C in an aqueous solution. The decoration of the SeNPs surface with lichenan endowed the L-SeNPs with superior antioxidant capability, and their free radicals scavenging ability exhibited in a dose-dependent manner. Furthermore, L-SeNPs showed excellent selenium controlled-release performance. In simulated gastric liquids, selenium release kinetics from L-SeNPs followed the Linear superimposition model, which was governed by the polymeric network retardation of macromolecular, while in simulated intestinal liquids, it was well fitted to the Korsmeyer-Peppas model and followed a Fickian mechanism controlled by diffusion., Competing Interests: Conflict of interest The authors have declared no conflicts of interest for this article., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Polysaccharide nanocrystals have led to the development of multifunctional and sustainable materials, but most are glucose-based carbohydrates derived from valuable natural sources. Here, we present a top-down strategy that enables one, for the first time, to isolate xylose-based hemicellulose nanocrystals from available industrial biowastes. By leveraging the selective oxidation of alkaline periodate, as high as 34 wt % solid yield is accessible. The hemicellulose nanocrystals exhibit platelet-like shapes (10-20 nm thickness, 30-80 nm wide), crystalline features, and superior dispersibility in water. We also showcase their successful interface applications for one-dimensional (1D) carbon nanotube (CNT) nanoinks and two-dimensional (2D) transition-metal dichalcogenide (TMD) nanozymes, which are comparable to the traditional cellulose nanocrystals. The scalable, low-cost, and sustainable hemicellulose nanocrystals can be envisioned to provide an alternative for glucose-based polysaccharide nanocrystals, as well as hold promise for the high-value utilization of biowastes.

Bone implants with the photothermal effect are promising for the treatment of bone tumor defects. Noble metal-based photothermal nanoagents are widely studied for their stable photothermal effect, but they are expensive and difficult to directly grow on implant surfaces. In contrast, non-noble metal photothermal nanoagents are economical but unstable. Herein, to develop a stable and economical photothermal film on bone implants, a Ni nanoparticle-doped oxide semiconductor film was grown in situ on Nitinol via the reduction of Ni-Ti-layered double hydroxides. Ni nanoparticles remained stable in the NiTiO 3 structure even when immersed in fluid for 1 month, and thus, the film presented a reliable photothermal effect under near-infrared light irradiation. The film also showed excellent in vitro and in vivo antitumor performance. Moreover, the nanostructure on the film allowed bone differentiation of mouse embryo cells (C3H10T1/2), and the released Ni ions supported the angiogenesis behavior of human vein endothelial cells. Bone implantation experiments further showed the enhancement of osteointegration of the modified Nitinol implant in vivo. This novel multifunctional Nitinol bone implant design offers a promising strategy for the therapy of bone tumor-related defects.

Nanoscaled nitrogen doped anatase TiO(2) with dominant (001) facets, which exhibited high photocatalytic activity and excellent photoelectrochemical properties under visible light irradiation, was successfully synthesized by solvothermal treatment of TiN in acidic NaBF(4) solution for the first time., (This journal is © The Royal Society of Chemistry 2012)

Abstract Large deformability and high sensitivity is difficult to be realized simultaneously in flexible sensors. Herein, taking advantage of the high permittivity and highly active surfaces of the ultrasmall barium titanate nanoparticles (BT NPs) and the high stretchability of the p(BA‐GMA) elastomer matrix, we propose a high‐performance soft stretchable sensor. The addition of the ultrasmall BT NPs can not only increase the permittivity and capacitance of polyacrylate‐matrix composite dielectric material to obtain a high sensitivity, but also basically maintains the excellent mechanical properties of the polymer matrix. The dielectric constants of the composite films increase from 5.68 to 13.13 at 10 kHz with the increase of BT NPs content from 0 to 15 vol.%, which results in a high capacitance of 236.16 pF for 15 vol.% BT/p(BA‐GMA) sensor. Combining the high permittivity and the large deformability (a maximal deformation of 87.2%), the 15 vol.% BT/p(BA‐GMA) sensor has high sensitivity and shows high linearity and stable output even if under dynamic measurement. The dual‐mode sensor that utilizes the orthogonality of capacitance‐resistance is designed, which shows excellent performance in monitoring human body movements and noncontact measurement. The results present that the BT/p(BA‐GMA)‐based sensor has high stability and reliability not exceed 65°C, which can meet the application requirements in dynamic monitoring.

Cocatalyst engineering with non‐noble metal nanomaterials can play a vital role in low‐cost, sustainable, and large‐scale photocatalytic hydrogen production. This research adopts slow carburization and simultaneous hydrocarbon reduction to synthesize carbon‐encapsulated Mo/Mo2C heterostructure nanoparticles, namely Mo/Mo2C@C cocatalyst. Experimental and theoretical investigations indicate that the Mo/Mo2C@C cocatalysts have a nearly ideal hydrogen‐adsorption free energy (ΔGH*), which results in the accelerated HER kinetics. As such, the cocatalysts are immobilized onto organic polymer semiconductor g‐C3N4 and inorganic semiconductor CdS, resulting in Mo/Mo2C@C/g‐C3N4 and Mo/Mo2C@C/CdS catalysts, respectively. In photocatalytic hydrogen evolution application under visible light, the Mo/Mo2C@C with g‐C3N4 and CdS can form the Schottky junctions via appropriate band alignment, greatly suppressing the recombination of photoinduced electron‐hole pairs. The surface carbon layer as the conducting scaffolds and Mo metal facilitates electron transfer and electron‐hole separation, favoring structural stability and offering more reaction sites and interfaces as electron mediators. As a result, these catalysts exhibit high H2 production rates of 2.7 mmol h−1 g−1 in basic solution and 98.2 mmol h−1 g−1 in acidic solution, respectively, which is significantly higher than that of the bench‐mark Pt‐containing catalyst. The proposed cocatalyst engineering approach is promising in developing efficient non‐noble metal cocatalysts for rapid hydrogen production. [ABSTRACT FROM AUTHOR]

A functional biopolymer was synthesized by introducing stearic acid (SA) to the backbone of xylan (X) obtained from viscose fiber mills. The SA–X derivatives were characterized by various tests for analysis of the functional properties. Effects on the esterification conditions including molar ratio, time and temperature were discussed, and the degree of substitution (DS) was in the range of 0.34–1.54. SA–X nanoparticles (SA–X NPs) were synthesized by dialysis, and the average particle size of the NPs was about 194 nm. Ketoprofen (KPF) was chosen as a hydrophobic model drug for the loading function evaluation, and the final encapsulation efficiency was about 64%. The KPF release profile in buffer standard solution with pH 11.0 and 2.0 were tested, and the final released amount were 43.6% and 53.8%, respectively. Thus, the fabrication of functional SA–X NPs provided a new way to improve the unreasonable application of factory biopolymer by-products. [ABSTRACT FROM AUTHOR]

We reported a green and simple method for biosynthesizing zinc oxide nanoparticles (ZnO NPs) usingCorymbia citriodoraleaf extract as reducing and stabilizing agent. SEM, EDX, XRD, UV–VIS spectroscopy, Raman spectroscopy and TGA have been used for characterizing the biosynthesized ZnO NPs. The results indicating the ZnO NPs synthesized byC. citriodoraleaf extract have high purity and the average size is 64 nm. The photocatalytic activity of the ZnO NPs has been investigated by degradation methylene blue under visible light irradiation. Due to the smaller size, the biosynthesized ZnO NPs showed an excellent photocatalytic performance. [ABSTRACT FROM PUBLISHER]

Abstract: Pt/CNTs, PtRu/CNTs, Pt/RuO2/CNTs and RuO2/Pt/CNTs were prepared to understand the role of RuO2 in anodic catalyst of direct methanol fuel cell (DMFC). The results show that the presence of Ru, no matter in alloy or in oxide, can improve the CO electrooxidation ability. RuO2 in Pt–Ru binary catalyst, which situates between CNTs and Pt particles, can exert its CO electrooxidation ability best. Another role of RuO2 in Pt–Ru binary catalyst is to promote Pt nanoparticles to disperse uniformly on CNTs to obtain larger EAS, resulting in higher activity of methanol electrocatalytic oxidation. [Copyright &y& Elsevier]

Abstract: Cuprous oxide (Cu2O) nanoparticles and microparticles have been prepared by liquid phase chemical synthesis. The samples were characterized by means of SEM, XRD, UV/DRS and XPS. It was presented that as-prepared Cu2O nanoparticles are substantially stable in ambient atmosphere and the Cu+ as main state exists on the surface of Cu2O nanoparticles. As-prepared Cu2O microparticles can exist stably as a Cu2O/CuO core/shell structure; and the Cu2+ as main state exists on the surface of Cu2O microparticles. The behaviors of adsorption, photocatalysis and photocorrosion of Cu2O particles with different sizes were investigated in detail. The results show that Cu2O nanoparticles are very easy to photocorrosion during the photocatalytic reaction, which cannot be used as photocatalyst directly to degrade organic compound, although as-prepared Cu2O nanoparticles exhibit special property of adsorption. Cu2O microparticles have a higher photocatalytic activity than Cu2O nanoparticles because of its slower photocorrosion rate, although Cu2O microparticles have much lower adsorption capacity than Cu2O nanoparticles. The mechanisms of photocatalysis and photocorrosion for Cu2O under visible light were also discussed. [Copyright &y& Elsevier]

Abstract: Nitrogen-doped TiO2 (N-TiO2) nanoparticles have been successfully prepared via a direct and simple hydrothermal reaction of a commercial Degussa P25 with triethanol amine as solvent and nitrogen source. As-prepared N-TiO2 was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible light (UV–vis) absorption spectra, electron probe microanalysis (EPMA) and X-ray photoelectron spectroscopy (XPS) techniques. The results confirm that hydrothermal reaction is an effective way to incorporate nitrogen into the TiO2 lattice, especially nitrogen substitute for titanium. The nitrogen concentration in TiO2 can be as high as 21% (molar ratio), which is described as Ti1− y O2− x N x + y (in this paper, x=0.36, y=0.27, i.e., Ti0.73O1.64N0.63). The chemical statuses of N have been assigned to N–Ti–O and O–N–O in the TiO2 lattice as identified by XPS. Photocatalytic degradation of methyl orange has been carried out in both UV–vis (simulated solar light) and the visible region (λ>400nm). N-TiO2 exhibits higher activity than the Degussa P25 TiO2 photocatalyst, particularly under visible-light irradiation. This study has developed a promising and practical pathway to new nitrogen-doped photocatalysts. [Copyright &y& Elsevier]

Size effect of Pt nanoparticle (NPs) on electrocatalysis should be investigated in a wide size range and a narrow distribution. The surfactants used for size control were detrimental to exploring size effect. However, the largest size of Pt colloidal NPs was limited to ∼5 nm without surfactant, which is insufficient for investigating size effect. In this work, surfactant-free Pt colloidal NPs with a wider size range from 1.8 to 10.0 nm were synthesized by controlling the ratio of NaOH and Pt salts in the ethylene glycol by oil-bath heating. Assisted by the precise control of Pt size, the size effect on the electrooxidation of CO, methanol and ethanol was studied, showing that the optimal size varied from the specific catalytic reaction. The synthesis extended the upper limit of large Pt NPs by surfactant-free method, showing potentials in preparing other precious metal NPs with a wide size range. [Display omitted] • Wide size range synthesis of surfactant-free colloidal Pt nanoparticles in alkaline ethylene glycol. • Water accelerates the rate of particle formation. • Temperature increases the conversion of Pt precursor rather than the size. • The wide range is sufficient to study size effect on electrocatalysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Lignin spheres were synthesized through dropping/dialysis nanoprecipitation. • The synergistic effect of parameters on the synthesis LMNPs was assessed. • The monodispersed LMNPs were produced from lignin fraction with low PDI. • The multifunctionality of PVA film was endowed by LMNPs with different structures. • The PVA/LMNPs film exhibited excellent mechanical property and UV shielding ability. Lignin, as an abundant natural polymer, has great potential in the synthesis of multifunctional micro/nanoparticles. However, the synthesis methods and parameters during the preparation process impact the controllability of lignin micro/nanoparticles (LMNPs), thereby affecting the performance of composite materials containing LMNPs. In this study, a green, simple, and applicable method for organosolv lignin was proposed for the synthesis of LMNPs using recyclable γ-valerolactone and the parameters (lignin concentration, stirring speed, dropping speed, water/solvent ratio, and lignin structure) were systematically investigated. The tuning of multiple properties of the composites was investigated by mixing LMNPs with polyvinyl alcohol (PVA). Results indicated that synthesis parameters affected the LMNPs formation, leading to aggregation/fusion of LMNPs. The obtained spherical LMNPs were electrostatically stable in pH 4–12, uniform (0.09 PDI), and excellent in thermal stability and antioxidant activity. Based on diffusion-restricted cluster–cluster aggregation, LMNPs around 157–442 nm were fabricated through π-π interactions. The PVA/LMNPs composite films showed excellent properties in terms of mechanical properties, thermal stability, UV shielding capacity, and hydrophobicity. The LMNPs with different structures improved the properties of polyvinyl alcohol films, providing a controllable approach for the development of biodegradable food/medical packaging materials and UV-shielding biomaterials. [ABSTRACT FROM AUTHOR]

In order to achieve long circulation time and high drug accumulation in the tumor sites via the EPR effects, anticancer drugs have to be protected by non-fouling polymers such as poly(ethylene glycol) (PEG), poly(ethylene oxide) (PEO), dextran, and poly(acrylic acid) (PAA). However, the dense layer of stealth polymer also prohibits efficient uptake of anticancer drugs by target cancer cells. For cancer therapy, it is often more desirable to accomplish rapid cellular uptake after anticancer drugs arriving at the pathological site, which could on one hand maximize the therapeutic efficacy and on the other hand reduce probability of drug resistance in cells. In this review, special attention will be focused on the recent potential strategies that can enable drug-loaded polymeric nanoparticles to rapidly recognize cancer cells, leading to enhanced internalization. [ABSTRACT FROM AUTHOR]

[Display omitted] • A polypyrrole coating strategy is proposed to mitigate the "under-voltage failure" and enhance the rate capability of sulfide-based electrodes for SIBs. • The holey structure of NiS 2 and the conductive polypyrrole coating boost fast interfacial pseudocapacitive charge storage. • The intermediate polysulfides are efficiently adsorbed by nitrogen atoms on the polypyrrole framework. • NiS 2 @PPy delivers high capacities of 393 and 373 mAh/g at 2.0 and 5.0 A/g over 1700 cycles. The application of transition metal sulfide-based anodes in sodium-ion batteries (SIBs) is held back by the poor rate capability and the knotty shuttle effect of polysulfides. Herein, a facile and scalable polypyrrole coating strategy is proposed to address the aforementioned issues. In-situ polymerization of pyrrole on porous NiS 2 nanoplatelets produces a polypyrrole-coated NiS 2 composite (NiS 2 @PPy). The holey structure of NiS 2 enhances ion transport while increasing contact area with polypyrrole shells. When used as the anode for SIBs, the conductive polypyrrole coating of NiS 2 @PPy can significantly accelerate the electrode kinetics by boosting fast interfacial pseudocapacitive charge storage, which accounts for ∼90 % of total capacity even at a low sweep rate of 0.1 mV s−1. Meanwhile, the conformal coating can accommodate the volume expansion of NiS 2 during cycling, enhancing the long-term durability of NiS 2 @PPy. More importantly, the intermediate polysulfides are efficiently adsorbed by the nitrogen atoms on the polypyrrole framework, thereby alleviating the under-voltage failure caused by the shuttle effect. Consequently, the as-prepared NiS 2 @PPy achieves high capacities of 393 and 373 mAh/g at 2.0 and 5.0 A/g over 1700 cycles. Motivated by the encouraging results in SIBs, we also explored the potentiality of NiS 2 @PPy for the potassium-ion batteries. [ABSTRACT FROM AUTHOR]

The graphical abstract was the following. The present study prepared an ultra-small Ag nanoparticles-loaded random coil lichenan nanocomposite (L-AgNP) through a green one-step reduction strategy using lichenan as the reducing agent. The homogeneous L-AgNP nanocomposite could catalyze the reduction of 4-nitrophenol (∼120 s, 34.34 × 10−3 s−1), and also exhibited favorable antibacterial activity for Escherichia coli and Staphylococcus aureus with more than 98 % disinfection ratio. [Display omitted] • Developed a micro AgNPs loaded homogeneous catalyst with lichenan as reductant. • The catalytic efficiency of L-AgNP was enhanced with smaller sizes/higher Ag content. • L-AgNP displayed high-efficiently reduced 4-nitrophenol and dyes with higher TOF. • L-AgNP could achieve more than 95 % conversion rate even after ten cycles. • L-AgNP exhibited excellent antibacterial activity against E. coli and S. aureus. Developing an eco-friendly and efficient homogeneous catalyst for treating complex wastewater containing toxic organic pollutants and bacteria is in significant demand. Herein, ultra-small Ag nanoparticles (NPs)-loaded random coil lichenan nanocomposite (L-AgNP) was prepared through a low-cost and green one-step in-situ reduction strategy using lichenan as the reducing agent. The random coil of lichenan acted as a micro-reactor to disperse and stabilize AgNPs via the Ag-O bonding interaction. In the participation of NaBH 4 , L-AgNP nanocomposite could achieve greater catalytic efficiency for catalyzing reduction of 4-nitrophenol (∼120 s, 34.34 × 10−3 s−1) with the smaller size of AgNPs or the higher content of Ag. The nanocatalyst also exhibited outstanding catalytic efficiency for congo red, rhodamine B, methylene blue, and methyl orange. The L-AgNP could be easily recycled through ethanol precipitation and continuously reused for ten cycles with a tiny loss of conversion rate. Furthermore, L-AgNP also displayed favorable antibacterial activity, inhibiting the growth of Escherichia coli and Staphylococcus aureus with more than 98 % disinfection ratio. This work provides a green strategy to develop polysaccharide-based multifunctional homogeneous catalysts focusing on wastewater purification. [ABSTRACT FROM AUTHOR]

In-situ generated (NiCo)Se 2 nanoparticles embedded in MOFs-derived NiCo layered double hydroxide nanoarrays show high energy density in hybrid supercapacitor. [Display omitted] Exploring novel structures consisting of multiple highly active components is a crucial challenge for supercapacitor applications. Using an in-situ self-templated method, we demonstrate the controlled fabrication of a fibrous hierarchical nanocomposite made of carbon microfibers covered with a layer of metal–organic framework (MOF) derived from nickel-cobalt layered double-hydroxide (NiCo-LDH) nanosheets decorated with (NiCo)Se 2 nanoparticles. The (NiCo)Se 2 nanoparticles attached tightly onto the surface of the two-dimensional NiCo-LDH, both of which were generated by the decomposition of the NiCo-based MOF, and exhibited multiple active sites that contributed to improved electrical conductivity, high capacity, and structural stability. Density functional theory calculations revealed that the density of states near the Fermi level was significantly enhanced, favoured OH– adsorption, and promoted the kinetics of the electrochemical reaction. Benefiting from the intrinsic synergetic contributions from the hierarchical nanoscale structure, the electrode made from the nanocomposite delivered an impressive capacity of 1394.2 F g−1 (702.7 C g−1) at 1 A g−1. Furthermore, a hybrid supercapacitor based on the developed nanocomposite demonstrated an energy density of 50.6 W h kg−1 and a power density of 800 W kg−1 with high cyclic stability. Our results suggest that the hierarchical nanocomposite can be a powerful electrode for advanced next-generation supercapacitors. [ABSTRACT FROM AUTHOR]

Abstract: Ruthenium(IV) oxide (RuO2) nanoparticles supported by herringbone carbon nanotubes (CNTs) were synthesized by a homogenous-oxidation-precipitation (HOP) method with H2O2. The morphology and composition of the resulting composite were characterized by TEM, XPS, XRD, TG and TPR. CNTs exhibited the better ability to induce the formation of highly dispersed nanoparticles, compared with common used supports, such as γ-Al2O3 and activated carbon. Amorphous hydrous RuO2 nanoparticles uniformly dispersed on the surface of CNTs. The average size of RuO2 was significantly reduced to 1.35nm. This result leads to the high activity and excellent selectivity, which has been demonstrated in the aerobic oxidation of alcohols to aldehydes or ketones. The new preparation technique of CNT-supported oxide nanoparticles reported in this paper has great potential for various catalytic applications. [Copyright &y& Elsevier]

Abstract: Porous hollow iron oxide nanoparticles (PHNPs) supported on carbon nanotubes (CNTs) were facilely synthesized by etching Fe@FexOy/CNT with dilute nitric acid aqueous solution at ambient temperature without the assistance of any surfactants and ligands. The mean diameter of hollow iron oxide nanoparticles was about 17nm, with a wall thickness of about 4nm. The formation mechanism of PHNPs is discussed based on the characterization results from TEM, XRD and H2-TPR. The combination of nanoscale Kirkendall effect and selective acid etching is proposed to be responsible for the formation of CNT supported PHNPs, through a transformation from core/void/shell structures to hollow nanoparticles. [Copyright &y& Elsevier]

Graphical abstract NMCNTs was synthesized though a facile method, displaying a high removal efficiency and stability in the acid solution and then re-utilized as the catalyst in the electrochemical reduction of CO 2 with a good faradic efficiency (over 90% total efficiency and about 50% for the CO production at 0.6 V). Highlights • Nitrogen doped magnetic carbon nanotubes (NMCNTs) were synthesized. • NMCNTs displayed a high efficiency in the Cr(VI) removal. • NMCNTs showed a high stability in the acid solution. • Recycled NMCNTs was an excellent catalyst for electrochemical reduction of CO 2. Abstract Highly efficient and acid-corrosion resistant for carbon adsorbent in hexavalent chromium removal is a significant property in the practical application. In this study, nitrogen doped carbon nanotubes with encapsulated Fe and Fe 3 C were synthesized through a facile pyrolysis procedure using melamine and ferric chloride as precursors, displaying an excellent efficiency and stability for hexavalent chromium removal. High maximum removal capacities with 35.26 and 970.87 mg g−1 were obtained in neutral and acid solutions, respectively, due to the adsorption process, reduction reaction between Fe0 or Fe2+ nanoparticles and Cr(VI) ions. The unexpected high stability in acid solution (pH at 1) after five recycles was observed for the first time, ascribed to N doping and the tubular structure with encapsulated ferric carbide, which could be resistant to the acid corrosion. After a simple treatment, the used adsorbent could be re-utilized as catalysts for the electrochemical reduction of CO 2 with high faradic efficiency (over 90% total efficiency and about 50% for CO production at −0.6 V), demonstrating a promising potential for reutilizing the used carbon adsorbents. [ABSTRACT FROM AUTHOR]

In recent years, tremendous efforts have been devoted to develop new photocatalyst with wide spectrum response for H 2 generation from water or aqueous solution. In this work, CdS nanoparticles (NPs) have been immobilized on hydrogenated three-dimensional (3D) branched TiO 2 nanorod arrays, resulting in a highly efficient photocatalyst, i.e, CdS/H-3D-TiO 2 . In addition, electrochemical reduction of H + ion is identified as a limiting step in the photocatalytic generation of H 2 at this catalyst, while here a Pt wired photocatalysis system (CdS/H-3D-TiO 2 /Pt-wire) is designed to overcome this barrier. Without the application of potential bias, visible light photocatalytic hydrogen production rate of CdS/H-3D-TiO 2 /Pt-wire is 18.42 μmol cm −2 h −1 , which is 11.2 times that of CdS/H-3D-TiO 2 without Pt (1.64 μmol cm −2 h −1 ). The Pt wire acts as an electron super highway between the FTO substrate and H + ions to evacuate the generated electrons to H + ions and catalyze the reduction reaction and consequently generate H 2 gas. This work successfully offers a novel direction for dramatic improvement in H 2 generation efficiency in photocatalysis field. [ABSTRACT FROM AUTHOR]

Non-noble metals are attractive alternatives to Pt co-catalysts for hydrogen production. Herein, Co nanoparticles were designed to uniformly deposit on the surface of TiO 2 nanotube arrays (Co/TNAs) via photo-deposition and reduction method. The structure and optical property of the Co/TNAs were characterized. Compared with pure TNAs, Co/TNAs showed a highly photocatalytic activity for hydrogen production without the Pt co-catalyst under UV–vis light irradiation. The study presents a promising practical way using non-noble metal as co-catalyst for photocatalytic splitting of water into hydrogen. [ABSTRACT FROM AUTHOR]

[Display omitted] • MnO 2 /CNTs catalysts for cumene oxidation is prepared. • Synergistic effect between MnO 2 and CNTs facilitating CHP decomposition is observed. • Kinetic modelling of 7 elementary steps is established. • MnO 2 /CNTs mainly accelerates the initial and terminal steps. • Enhanced k 80 and reduced E a are obtained over MnO 2 /CNTs. Synergistic effects between the carbon materials and metal oxides usually are considered as the significant factor in the selective oxidation of hydrocarbons. In current study, MnO 2 /CNTs catalysts were prepared under mild condition and applied in the cumene oxidation. As high as 73.44% cumene conversion with 59.06% selectivity of 2-phenyl-2-propanol(PP) was obtained over 21.23-MnO 2 /CNTs, which is much higher than those of CNTs-catalysis and MnO 2 -catalysis systems. The decomposition of cumene hydroperoxide (CHP), a key step for cumene oxidation, was proved to be facilitated by the interaction between MnO 2 nanoparticles and CNTs, which also confirmed from the DFT calculations. These results demonstrated that the synergistic effect between MnO 2 nanoparticles and CNTs would greatly enhance the activity and tune the distribution of products selectivity. The kinetic modeling study in this work further revealed that the interactions between MnO 2 nanoparticles and CNTs would accelerate all the elementary steps, especially, the homolytic cleavage of CHP. The reaction rate constant (k 80 = 9 h−1) for 21.23-MnO 2 /CNTs is 450-folds of CNTs (k 80 = 0.02 h−1). Moreover, the concentration distributions of acetophenone (AP) and PP were well illustrated from the kinetic study. [ABSTRACT FROM AUTHOR]

To design low-cost and efficient cathode electrocatalysts and push forward the commercialization of fuel cells, low platinum content catalyst supported on nitrogen and phosphorus-codoped carbon nanotubes (Pt/NP-CNTs) for the oxygen reduction reaction (ORR) were prepared. Electrochemical tests demonstrated that the Pt/NP-CNTs catalyst exhibited much high ORR activity and remarkable stability in acidic media due to the strong interaction between NP-CNT support and Pt catalyst evidenced by the calculation of the density functional theory, showing a good potential application for a future low-cost proton exchange membrane fuel cell device. [ABSTRACT FROM AUTHOR]

Abstract: Cu(OH)2/TNAs photocatalyst was prepared by loading Cu(OH)2 nanoparticles on TiO2 nanotube arrays (TNAs) using a chemical bath deposition method. The amount of Cu(OH)2 loaded on the arrays was controlled by the repeated deposition times. The prepared catalyst was used to generate hydrogen under simulated solar light irradiation, and the results demonstrated that the hydrogen yield of Cu(OH)2/TNAs was 20.3 times that of the pure TNAs. Furthermore, the photocatalytic efficiency for hydrogen production decreased only 5.8% after five cycles, indicating that Cu(OH)2/TNAs photocatalyst showed excellent stability and reusability. This work presents an applicable and facile method to fabricate a highly active and stable photocatalyst for hydrogen production. [Copyright &y& Elsevier]

Abstract: Monodispersed hollow Fe3O4 spheres with different diameters and shell thickness were synthesized by a simple solvothermal process and were investigated as anode materials for lithium ion batteries (LIBs). The shell of the hollow spheres exhibited porous structure composed of aggregated Fe3O4 nanoparticles. The composition and morphology of the obtained samples were characterized by X-ray powder diffraction (XRD), Raman spectra, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). A novel formation mechanism was proposed based on the results of time-dependent reactions. The electrochemical tests of the hollow Fe3O4 spheres were performed to determine the reversible capacity, rate and cycling performance as anode materials for LIBs. The Fe3O4 obtained from the reaction at 200°C for 48h exhibited the best specific capacity and capacity retention and superior rate performance compared to other Fe3O4 spheres, which is ascribed to their reasonable particle size, high crystallinity and hollow spherical structures. Different conductive additive were used to investigate the electrochemical performance of Fe3O4 hollow spheres. The binary conductive additives containing acetylene black (AB) and carbon nanobutes (CNTs) improved the electrochemical performance of the Fe3O4 hollow spheres obviously. The results reveal that there is a synergistic effect of the particle size, crystallinity and conductive agents on the electrochemical properties of the hollow Fe3O4 spheres. [Copyright &y& Elsevier]

Abstract: Hierarchically structured TiO2 (HST) films composed of top porous nanoparticle layer and underneath nanotube array layer are obtained by an anodization method on fluorine doped tin oxide surfaces. Compared with the TiO2 nanotube arrays photoanode on Ti substrate, the HST photoanode exhibits a higher photoelectrocatalytic activity towards the oxidation of water and organics (e.g., glucose). [Copyright &y& Elsevier]

Abstract: The structural stability and transformations of Mo carbide, nitride and phosphide were investigated under various atmosphere conditions by X-ray diffraction (XRD). The results indicated that the order of structural stability of these Mo-based compounds was as follows: Mo2N