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Two-dimensional covalent organic frameworks (2D COFs), featuring a large surface area and 1D pore structure, serve as promising scaffolds for anchoring functional guest compounds, which can significantly enhance their performance and thus expand their potential applications. Postsynthetic strategy for COFs functionalization is versatile but challenging because of their tedious procedure with high time and energy consumption, generation of excess reaction waste, and damage to COF crystallinity. We report in this work a general strategy for the synthesis of inorganic nanocompound-functionalized COF composites in a one-pot way. Specifically, a high-crystallinity nanoscale molybdenum compound is successfully introduced into a COF skeleton with high dispersion in situ during the crystallization process of the COF induced by gamma ray radiation under ambient conditions. The obtained COF@Mo composites exhibit remarkable sorption performance for methylene blue and many other organic dyes in aqueous solution with the advantages of ultrarapid uptake dynamics and high removal efficiency.

The modulation of Z-scheme charge transfer is essential for efficient heterostructure toward photocatalytic CO 2 reduction. However, constructing a compact hetero-interface favoring the Z-scheme charge transfer remains a great challenge. In this work, an interfacial Nb-O-Sn bond and built-in electric field-modulated Z-scheme O v -SnO 2 /SnNb 2 O 6 heterojunction was prepared for efficient photocatalytic CO 2 conversion. Systematic investigations reveal that an atomic-level interface is constructed in the O v -SnO 2 /SnNb 2 O 6 heterojunction. Under simulated sunlight irradiation, the obtained O v -SnO 2 /SnNb 2 O 6 photocatalyst exhibits a high CO evolution rate of 147.4 μmol h -1 g -1 from CO 2 reduction, which is around 3-fold and 3.3-fold of SnO 2 /SnNb 2 O 6 composite and pristine SnNb 2 O 6 , respectively, and favorable cyclability by retaining 95.8% rate retention after five consecutive tests. As determined by electron paramagnetic resonance spectra, in situ Fourier transform infrared spectra, and density functional theory calculations, Nb-O-Sn bonds and built-in electric field induced by the addition of oxygen vacancies jointly accelerate the Z-scheme charge transfer for enhanced photocatalytic performance. This work provides a promising route for consciously modulating Z-scheme charge transfer by atomic-level interface engineering to boost photocatalytic performance.

Natural articular cartilages exhibit extraordinary lubricating properties and excellent load-bearing capacity based on their penetrated surface lubricated biomacromolecules and gradient-oriented hierarchical structure. Hydrogels are considered as the most promising cartilage replacement materials due to their excellent flexibility, good biocompatibility, and low friction coefficient. However, the construction of high-strength, low-friction hydrogels to mimic cartilage is still a great challenge. Here, inspired by the structure and functions of natural articular cartilage, anisotropic hydrogels with horizontal and vertical orientation structure were constructed layer by layer and bonded with each other, successfully developing a bilayer oriented heterogeneous hydrogel with a high load-bearing capacity, low friction, and excellent fatigue resistance. The bilayer hydrogel exhibited a high compressive strength of 5.21 ± 0.45 MPa and a compressive modulus of 4.06 ± 0.31 MPa due to the enhancement mechanism of the anisotropic structure within the bottom anisotropic hydrogel. Moreover, based on the synergistic effect of the high load-bearing capacity of the bottom layer and the lubrication of the surface layer, the bilayer hydrogel possesses excellent biotribological properties in hard/soft (0.032) and soft/soft (0.028) contact, which is close to that of natural cartilage. It is worth noting that the bilayer oriented heterogeneous hydrogel is able to withstand repeated loading without fatigue crack. Therefore, this work could open up a new avenue for constructing cartilage-like materials with both high strength and low friction.

Efficient xenon/krypton (Xe/Kr) separation has played an important role in industry due to the wide application of high-purity Xe and with regard to the safe disposal of radioactive noble gases ( 85 Kr and 133 Xe). A less energy-demanding separation technology, adsorptive separation using porous solid materials, has been proposed to replace the traditional cryogenic distillation with intensive energy consumption. As a cutting-edge class of porous materials, metal-organic frameworks (MOFs) featuring permanent porosity, designable chemical functionalities, and tunable pore sizes hold great promise for Xe/Kr separation. Here, we report a two-dimensional (2D) lanthanide-organic framework (termed LPC-MOF, [Eu(Ccbp)(NO 3 )(HCOO)]·DMF 0.3 (H 2 O) 2.5 ) with one-dimensional (1D) local positively charged rhomboid channels whose size matches well with the kinetic diameter of Xe, leading to its superior Xe/Kr separation performance. Column breakthrough experiments demonstrate that LPC-MOF exhibits a high Xe/Kr selectivity of 12.4 and an Xe adsorption amount of 3.39 mmol kg -1 under simulated conditions for real used nuclear fuel (UNF)-reprocessing plants. Furthermore, density functional theory (DFT) calculations elucidate not only the intrinsic mechanisms of Xe/Kr separation at the molecular level but also the detailed influence of the local positive charge (N + ) on the performance of Xe/Kr separation in the MOF system.

The material for managing and monitoring waste made from the waste itself is an excellent example of cyclic utilization, which could reduce issues and be more sustainable. A three-dimensional porous uranyl phosphonate MOF ( UPF-105 ) was synthesized via a hydrothermal method. UPF-105 is stable in aqueous solution with pH in the range of 1-11 and maintains crystallinity below 215 °C. The uncoordinated phosphonate groups in the channels act as functional anchors to selectively capture uranyl ions, with a maximum uranium adsorption capacity of 170.23 mg g -1 . The fluorescence of UPF-105 makes it a good candidate for a uranyl ion sensor in uranium-contaminated solutions with concentrations in the range of 5-90 ppm.

The chemical bond diversity and flexible reactivity of biomass-derived ethanol make it a vital feedstock for the production of value-added chemicals but result in low conversion selectivity. Herein, composite catalysts comprising SiO 2 -coated single- or multiparticle Au cores hybridized with TiO 2 nanoparticles (mono- or multi-Au@SiO 2 /TiO 2 , respectively) were fabricated via electrostatic self-assembly. The C-H and O-H bonds of ethanol were selectively activated (by SiO 2 and TiO 2 , respectively) under irradiation to form CH 3 CH • (OH) or CH 3 CH 2 O • radicals, respectively. The formation and depletion kinetics of these radicals was analyzed by electron spin resonance to reveal marked differences between mono- and multi-Au@SiO 2 /TiO 2 . Consequently, the selectivity of these catalysts for 1,1-diethoxyethane after 6 h irradiation was determined as 81 and 99%, respectively, which was attributed to the more pronounced effect of localized surface plasmon resonance for multi-Au@SiO 2 /TiO 2 . Notably, only acetaldehyde was formed on a Au/TiO 2 catalyst without a SiO 2 shell. Fourier transform infrared (FTIR) spectroscopy indicated that the C-H adsorption of ethanol was enhanced in the case of multi-Au@SiO 2 /TiO 2 , while NH 3 temperature-programmed desorption and pyridine adsorption FTIR spectroscopy revealed that multi-Au@SiO 2 /TiO 2 exhibited enhanced surface acidity. Collectively, the results of experimental and theoretical analyses indicated that the adsorption of acetaldehyde on multi-Au@SiO 2 /TiO 2 was stronger than that on Au/TiO 2 , which resulted in the oxidative coupling of ethanol to afford 1,1-diethoxyethane on the former and the dehydrogenation of ethanol to acetaldehyde on the latter.

High-performance tactile sensors are urgently demanded in various intensive interactive scenarios, e.g., texture detection, robotic interaction with fragile objects, and motion direction recognition, where dynamic conditions are involved with complex tangential forces or vibrations. Although many microstructured/porous sensors can perceive tangential forces, their isotropic structures that lack programmability lead them to be incapable of sensing the direction of forces and restrain their tunability for complex situations, e.g., a wide sensing range for large forces and high sensitivity for gentle forces. Here, by tuning the programmable microstructures (microcolumns and microfilms) of an elastomeric active layer, we propose a simple principle to flexibly tune the shear sensitivity of an anisotropic porous sensor and bring a 10-fold distinction of anisotropy with a wide range of shear sensitivity (from 0.07 to 0.7 N -1 ). The fabricated tactile sensors can be used in various robotic manipulations resiliently, for instance, morphology and topology identification of curved surfaces, delicate interactive manipulations, and recognizing the relative motion of two contacting objects. Our work introduces a simple and effective strategy for tailoring flexible shear-sensitive sensors for diverse dexterous robotic manipulations during complex interactions.

Ceramics including oxides, carbides, nitrides, borides, carbonitrides, silicates, and MAX phases have wide applications in electrode materials, high-temperature structural materials, and anticorrosive materials for harsh environments. However, the difficulty in processing ceramics with complex shapes from green powders has been restricting applications in emerging areas. Herein, polymer-derived ceramics (PDCs) were used to assist the pressureless processing of MAX phase particles. The processing temperature could be lowered by 400 to 600 °C, which is favorable for both industrialization and engineering applications. The good processability of MAX-preceramic polymer mixtures and high accuracy of replica from preceramic polymer make it possible to fabricate artificial objects with complex shapes and fine texture. This method provides a method to fabricate MAX phase ceramics/composites, as well as some other ceramics.

Antifreezing gels are promising in diverse engineering applications such as structural soft matters, sensors, and wearable devices. However, the capability of fast self-healing and reversible adhesiveness still remain a huge challenge for gels at extreme temperatures. Here, we proposed a solvent-involved cross-linking system composed of polyacrylic acid, polyvinyl alcohol, borax, ethylene glycol, and water, capable of antifreezing below -90 °C. It was not only antifreezing, anticrystalline, and abundant in dynamic bonds but also highly transparent, stretchable (over 800%), and conductive over the scope of temperature from -60 to 60 °C. Moreover, this gel could self-heal within 1 min and repeatedly adhere to multiple substrates including glass, metal, and rubber with an adhesive strength greater than 18 kPa. These key functions of the gel could be mostly preserved after 5 days of storage at 70% relative humidity. It is anticipated that our research opens a new scope for high-performance extreme environment-tolerant adhesives or wearable devices.

Despite that two-dimensional transition metal carbides and carbonitrides (MXenes) are burgeoning candidates for remediation of environmental pollutants, the construction of robust functionalized MXene nanosheets with a high affinity for target heavy metal ions and radionuclides remains a challenge. Here we report the successful placement of amidoxime chelating groups on Ti 3 C 2 T x MXene surface by diazonium salt grafting. The introduction of amidoxime functional groups significantly enhances the selectivity of Ti 3 C 2 T x nanosheets for uranyl ions and also greatly improves their stability in aqueous solution, enabling efficient, rapid, and recyclable uranium extraction from aqueous solutions containing competitive metal ions. Benefiting from the excellent conductivity of MXenes, the amidoxime functionalized Ti 3 C 2 T x nanosheets show outstanding electrochemical performance such that when loaded on carbon cloth the application of an electric field increases the uranium adsorption capacity from 294 to 626 mg/g, outperforming all organic electrochemical sorption materials reported previously. The present work provides an effective strategy to functionalize MXene nanosheets with fundamental implications for the design of MXene-based selective electrosorption electrode materials.

Contamination of 99 TcO 4 - , a problematic radioactive anion in the nuclear fuel cycle, in groundwater has been observed in a series of legacy nuclear sites, representing a notable radiation hazard and environmental concern. The development of convenient, rapid, and sensitive detection methods is therefore critical for radioactivity control and remediation tasks. Traditional detection methods suffer from clear demerits of either the presence of large interference from coexisting radioactive species (e.g., radioactivity counting methods) or the requirement of extensive instrumentation and analysis procedure (e.g., mass spectrometry). Here, we constructed a luminescent iridium(III) organometallic complex (Ir(ppy) 2 (bpy) + ; ppy = 2-phenylpyridine, bpy = 2,2 ' -bipyridine)-grafted porous aromatic framework (Ir-PAF) for the first time, which can be utilized for efficient, facile, and selective detection of trace ReO 4 - /TcO 4 - in aqueous solutions. Importantly, the luminescence intensity of Ir-PAF is greatly enhanced in the presence of ReO 4 - /TcO 4 - , giving rise to a distinct turn-on sensor with the detection limit of 556.9 μg/L. Such a superior detection capability originates from the highly selective and strong interaction between ReO 4 - /TcO 4 - and Ir(ppy) 2 (bpy) + , leading to an efficient pre-enrichment of ReO 4 - /TcO 4 - during analysis and subsequently a much weaker nonradiative decay of the luminescence of Ir(ppy) 2 (bpy) + , as illustrated by density functional theory (DFT) calculation as well as quantum yield and fluorescence lifetime measurements. Successful quantification of trace ReO 4 - in simulated Hanford low-activity waste (LAW) solution containing large excess of Cl - , NO 3 - , and NO 2 - was demonstrated, highlighting the bright future of luminescent PAFs in the area of chemical sensing.

With respect to cyanoacryclic acid as the traditional acceptor and anchoring group in dye-sensitized solar cells, the introduction of stronger electron-deficient groups has greatly expanded the scope of molecular design and increased their efficiencies for organic dyes. In this contribution, benzothiadiazole (BTD) was selected as a representative acceptor to illustrate the influence of its position on the photophysical properties and corresponding photovoltaic performances. Through the insertion of BTD in different positions of the framework with the same composition units and orders, four sensitizers were designed and synthesized. The structure-property relationship demonstrated the preference of the suitable position of an electron acceptor for optimization of the spectra response and interfacial charge transfer. In our system, dye LI-96 with BTD in the middle of the conjugated bridge showed the broadest spectrum and achieved the best photovoltaic performance (8.25%), which may pave a new way to design or optimize the efficient sensitizers by rational design of the acceptor position.

The physiochemical properties of nanoparticles (NPs), including surface charge, will affect their uptake, transformation, translocation, and final fate in the environment. In this study, we compared the phytoxoxicity and transport behaviors of nano CeO 2 (nCeO 2 ) functionalized with positively charged (Cs-nCeO 2 ) and negatively charged (PAA-nCeO 2 ) coatings. Cucumber seedlings were hydroponically exposed to 0-1000 mg/L of Cs-nCeO 2 and PAA-nCeO 2 for 14 days and the contents, distribution, translocation, and transformation of Ce in plants were analyzed using inductively coupled plasma mass spectrometry, micro X-ray fluorescence (μ-XRF), and X-ray absorption near-edge spectroscopy (XANES), respectively. Results showed that the seedling growth and Ce contents in plant tissues were functions of exposure concentrations and surface charge. Cs-nCeO 2 was adsorbed strongly on a negatively charged root surface, which led to significantly higher Ce contents in the roots and lower translocation factors of Ce from the roots to shoots in Cs-nCeO 2 group than in PAA-nCeO 2 group. The results of μ-XRF showed that Ce elements were mainly accumulated at the root tips and lateral roots, as well as in the veins and at the edge of leaves. XANES results revealed that the proportion of Ce(III) was comparable in the plant tissues of the two groups. We speculated that Cs-nCeO 2 and PAA-nCeO 2 were partially dissolved under the effect of root exudates, releasing Ce 3+ ions as a result. Then, the Ce 3+ ions were transported upward in the form of Ce(III) complexes along the vascular bundles and eventually accumulated in the veins. The other portion of Cs-nCeO 2 and PAA-nCeO 2 entered the roots through the gap of a Casparian strip at root tips/lateral roots and was transported upward as intact NPs and finally accumulated at the edge of the blade. This study will greatly advance our information on how the properties of NPs influence their phytotoxicity, uptake, and subsequent trophic transfer in terrestrial food webs.

The clinical treatment of aggressive glioma has been a great challenge, mainly because of the complexity of the glioma microenvironment and the existence of the blood-brain tumor barrier (BBTB)/blood-brain barrier (BBB), which severely hampers the effective accumulation of most therapeutic agents in the glioma region. Additionally, vasculogenic mimicry (VM), angiogenesis, and glioma stem cells (GSC) in malignant glioma also lead to the failure of clinical therapy. To address the aforementioned issues, a whole-process glioma-targeted drug delivery strategy was proposed. The D A7R peptide has effective BBTB-penetrating and notable glioma-, angiogenesis-, and VM-targeting abilities. Herein, we designed a myristic acid modified D A7R ligand (MC- D A7R), which combines tumor-homing D A7R with BBB-penetrable MC. MC- D A7R was then immobilized to PEGylated liposomes (MC- D A7R-LS) to form a whole-process glioma-targeting system. MC- D A7R-LS exhibited exceptional internalization in glioma, tumor neovascular, and brain capillary endothelial cells. Enhanced BBTB- and BBB-traversing efficiencies were also observed on MC- D A7R-LS. Ex vivo imaging on brain tumors also demonstrated the feasibility of MC- D A7R-LS in intracranial glioma-homing, whereas the immunofluorescence studies demonstrated its GSC and angiogenesis homing. Furthermore, doxorubicin-loaded MC- D A7R-LS accomplished a remarkable therapeutic outcome, as a result of a synergistic improvement on the glioma microenvironment. Our study highlights the potential of the MC-modified D A7R peptide as a great candidate for the whole-process glioma-targeted drug delivery.

Assembly of organic semiconductors with ordered crystal structure has been actively pursued for electronics applications such as organic field-effect transistors (OFETs). Among various film deposition methods, solution-based film growth from small molecule semiconductors is preferable because of its low material and energy consumption, low cost, and scalability. Here, we show scalable and controllable directed assembly of highly crystalline 2,7-dioctyl[1]benzothieno[3,2- b][1]benzothiophene (C8-BTBT) films via a dip-coating process. Self-aligned stripe patterns with tunable thickness and morphology over a centimeter scale are obtained by adjusting two governing parameters: the pulling speed of a substrate and the solution concentration. OFETs are fabricated using the C8-BTBT films assembled at various conditions. A field-effect hole mobility up to 3.99 cm 2 V -1 s -1 is obtained. Owing to the highly scalable crystalline film formation, the dip-coating directed assembly process could be a great candidate for manufacturing next-generation electronics. Meanwhile, the film formation mechanism discussed in this paper could provide a general guideline to prepare other organic semiconducting films from small molecule solutions.

Real-time and accurate detection of pH in aqueous solution is of great significance in chemical, environmental, and engineering-related fields. We report here the use of 8-hydroxyquinoline-functionalized covalent organic framework (COF-HQ) for dual-mode pH sensing. In the fluorescent mode, the emission intensity of COF-HQ weakened as the pH decreased, and also displayed a good linear relationship against pH in the range from 1 to 5. In addition, COF-HQ showed discernible color changes from yellow to black as the acidity increased and can be therefore used as a colorimetric pH sensor. All these changes are reversible and COF-HQ can be recycled for multiple detection runs owing to its high hydrolytical stability. It can be further assembled into a mixed matrix membrane for practical applications.

The accurate detection of UV radiation is required in a wide range of chemical industries and environmental or biological related applications. Conventional methods taking advantage of semiconductor photodetectors suffer from several drawbacks such as sophisticated synthesis and manufacturing procedure, not being able to measure the accumulated UV dosage as well as high defect density in the material. Searching for new strategies or materials serving as precise UV dosage sensor with extremely low detection limit is still highly desirable. In this work, a radiation resistant uranium coordination polymer [UO 2 (L)(DMF)] (L = 5-nitroisophthalic acid, DMF = N,N-dimethylformamide, denoted as compound 1) was successfully synthesized through mild solvothermal method and investigated as a unique UV probe with the detection limit of 2.4 × 10 -7 J. On the basis of the UV dosage dependent luminescence spectra, EPR analysis, single crystal structure investigation, and the DFT calculation, the UV-induced radical quenching mechanism was confirmed. Importantly, the generated radicals are of significant stability which offers the opportunity for measuring the accumulated UV radiation dosage. Furthermore, the powder material of compound 1 was further upgraded into membrane material without loss in luminescence intensity to investigate the real application potentials. To the best of our knowledge, compound 1 represents the most sensitive coordination polymer based UV dosage probe reported to date.

Because of the popularity of smart electronics, multifunctional energy storage devices, especially electrochromic supercapacitors (SCs), have attracted tremendous research interest. Herein, a solid-state electrochromic asymmetric SC (ASC) window is designed and fabricated by introducing WO 3 and polyaniline as the negative and positive electrodes, respectively. The two complementary materials contribute to the outstanding electrochemical and electrochromic performances of the fabricated device. With an operating voltage window of 1.4 V and an areal capacitance of 28.3 mF cm -2 , the electrochromic devices show a high energy density of 7.7 × 10 -3 mW h cm -2 . Meanwhile, they exhibit an obvious and reversible color transition between light green (uncharged state) and dark blue (charged state), with an optical transmittance change between 55 and 12% at a wavelength of 633 nm. Hence, the energy storage level of the ASC is directly related to its color and can be determined by the naked eye, which means it can be incorporated with other energy cells to visual display their energy status. Particularly, a self-powered and color-indicated system is achieved by combining the smart windows with commercial solar cell panels. We believe that the novel electrochromic ASC windows will have great potential application for both smart electronics and smart buildings.

Enrichment of uranyl from seawater is crucial for the sustainable development of nuclear energy, but current uranium extraction technology suffers from multiple drawbacks of low sorption efficiency, slow uptake kinetics, or poor extraction selectivity. Herein, we prepared the first example of amidoxime appended metal-organic framework UiO-66-AO by a postsynthetic modification method for rapid and efficient extraction of uranium from seawater. UiO-66-AO can remove 94.8% of uranyl ion from Bohai seawater within 120 min and 99% of uranyl ion from Bohai seawater containing extra 500 ppb uranium within 10 min. The uranyl sorption capacity in a real seawater sample was determined to be 2.68 mg/g. In addition, the recyclability of the UiO-66-AO framework was demonstrated for at least three adsorption/desorption cycles. The origin for the superior sorption capability was further probed by extended X-ray absorption fine structure (EXAFS) analysis on the uranium-sorbed sample, suggesting multiple amidoxime ligands are able to chelate uranyl(VI) ions, forming a hexagonal bipyramid coordination geometry.

Bilayer Bi 0.85-x Pr 0.15 RE x Fe 0.97 Mn 0.03 O 3 /CuFe 2 O 4 (BPRE x FMO/CuFO, RE = Sr, Dy) thin films were prepared on FTO/glass substrates by the chemical solution deposition method. The structure transition does not appear after ion doping, which is confirmed by XRD and its refined results. The samples remain in the trigonal R3c:H structure in the BFO phase and in the tetragonal I41/amd structure in the CuFO phase. The asymmetric character of leakage current density curves and resistive switching effects have been explored. And the ion substitution impacts on the resistive switching effects may be due to the existence of local fields. Under the applied electric field, carries are accumulated and arranged directionally at the interface between the BFO and CuFO layers to form the local electric field. Such local field is affected by ion dopants, and the field compensates or weakens the applied electrical field. The reinforced or weakened resistive behavior is dependent on the direction of the local field and the injection of electrons. The polarization switching currents of the BPFMO/CuFO, BPSFMO/CuFO, and BPDFMO/CuFO samples, whose distribution fields are proportional to the local electrical fields, are 0.0070, 0.0049, and 0.0074 A under the positive applied field, respectively. And the remanent polarization is increased to 74.4, 73.5, and 84.3 μC/cm 2 of the doped samples, respectively.

Effective detection of chromate anions in aqueous solution is highly desirable because of their high solubility, environmental mobility, carcinogenicity, and bioaccumulation effect. A new strategy for precise detection of chromate anions in the presence of a large excess of other anions, such as Cl - , NO 3 - , and HCO 3 - , in drinking water and natural water systems remains a challenge. Herein, a hydrolytically stable cationic luminescent europium(III)-based metal organic framework (MOF), 1, was successfully synthesized and investigated as a luminescent sensor that exhibits instant and selective luminescence quenching properties toward chromate ions in aqueous solutions. Moreover, 1 can be introduced into high-ionic-strength water system (e.g., seawater) for chromate detection as a consequence of the excellent sensing selectivity. The real environmental application of 1 as a chromate probe is studied in deionized water, lake water, and seawater. The detection limits in these aqueous media are calculated to be 0.56, 2.88, and 1.75 ppb, respectively. All of these values are far below the maximum contamination standard of Cr(VI) in drinking water of 100 ppb, defined by the U.S. Environmental Protection Agency. This excellent chromate sensing capability originates from the fast enrichment of chromate ions in solids of 1 from solutions, followed by efficient energy transfer from the MOF skeleton to the chromate anion, as demonstrated by solution absorption spectroscopy, X-ray diffraction, and chromate uptake kinetics and isotherm investigations. To the best of our knowledge, 1 possesses the lowest chromate detection limit among all reported MOFs up to date and is the only MOF material reported for chromate sensing application under environmentally relevant conditions with high ionic strengths.

Acceptors in traditional dyes are generally designed closed to TiO 2 substrate to form a strong electronic coupling with each other (e.g., cyanoacrylic acid) to enhance the electron injection for the high performance of the corresponding solar cells. However, some newly developed dyes with chromophores or main acceptors isolated from anchoring groups also exhibit comparable or even higher performances. To investigate the relatively untouched electronic coupling effect in dye-sensitized solar cells, a relatively precise method is proposed in which the strength is adjusted gradually by changing isolation spacers between main acceptors and anchoring groups to partially control the electronic interaction. After an analysis of 3 different groups of 11 sensitizers, it is inferred that the electronic coupling should be kept at a suitable level to balance the electron injection and recombination. Based on a reference dye LI-81 possessing a cyanoacrylic acid as acceptor and anchoring group, both photocurrent and photovoltage are synergistically improved after the properties of isolation spacers were changed through the adjustment of the length, steric hindrance, and push-pull electronic characteristic. Accordingly, the rationally designed dye LI-87 with an isolation spacer of thiophene ethylene gives an efficiency of 8.54% and further improved to 9.07% in the presence of CDCA, showing a new way to develop efficient sensitizers.

Efficient nuclear waste treatment and environmental management are important hurdles that need to be overcome if nuclear energy is to become more widely used. Herein, we demonstrate the first case of using two-dimensional (2D) multilayered V2CTx nanosheets prepared by HF etching of V2AlC to remove actinides from aqueous solutions. The V2CTx material is found to be a highly efficient uranium (U(VI)) sorbent, evidenced by a high uptake capacity of 174 mg g(-1), fast sorption kinetics, and desirable selectivity. Fitting of the sorption isotherm indicated that the sorption followed a heterogeneous adsorption model, most probably due to the presence of heterogeneous adsorption sites. Density functional theory calculations, in combination with X-ray absorption fine structure characterizations, suggest that the uranyl ions prefer to coordinate with hydroxyl groups bonded to the V-sites of the nanosheets via forming bidentate inner-sphere complexes.

One of the most promising candidates for photoelectrochemical (PEC) water splitting photoanode is hematite (α-Fe2O3) due to its narrow bandgap and chemical stability. However, the poor bulk/surface kinetics of hematite limits its PEC performance. Herein, a facile two-step approach is reported to synergistically improve the PEC performance of Fe2O3. First, through bulk engineering of Ti doping, the photocurrent density of Ti-Fe2O3 photoanode (1.68 mA cm(-2) at 1.23 VRHE) shows a 3-fold increase compared with that of pure Fe2O3 photoanode (0.50 mA cm(-2) at 1.23 VRHE). Second, the photocurrent density of Ti-Fe2O3 photoanode could be further enhanced to 2.31 mA cm(-2) by surface engineering of FeOOH. The enhanced PEC water splitting performance is proposed to be the synergistic effect of bulk and surface engineering, which can be mainly attributed to the great increase of charge separation efficiency and surface transfer efficiency.

Accumulation of nanoparticles in solid tumors depends on their extravasation, but their efficacy is often compromised by intrinsic physiological heterogeneity in tumors. The conventional solutions to circumvent this problem are size control of nanoparticles or increasing the vascular permeability. The aim of this study is to investigate the combination effect of size variation of stimuli-responsive nanoparticles and improved vascular permeability triggered by near-infrared (NIR) light irradiation. Doxorubicin (DOX), a clinically proven drug for bladder cancer, was encapsulated in the nanocomposites with high loading content up to 45%. We show that NIR light-responsive size-switchable nanocarriers could considerably enhance the tumor-targeting of DOX in bladder tumor-bearing mice. Moreover, a combination of NIR-induced hyperthermia and DOX-mediated chemotherapy resulted in remarkable inhibition of tumor growth in mice. Histological results suggest that the change in morphology of tumor microvasculature may account for enhanced extravasation and accumulation of the nanodrugs upon NIR irradiation. Together, these data suggest that external stimuli-responsive drug delivery system offers a safe and effective means of targeted chemo/photothermal therapy.

Although conventional radiotherapy (RT) has been widely used in the clinic to treat cancer, it often has limited therapeutic outcomes and severe toxic effects. There is still a need to develop theranostic agents with both imaging and RT-enhancing functions to improve the accuracy and efficiency of RT. Herein we synthesize Au@MnS@ZnS core/shell/shell nanoparticles with polyethylene glycol (PEG) functionalization, yielding Au@MnS@ZnS-PEG nanoparticles with great stability in different physiological solutions and no significant cytotoxicity. It is found that Au@MnS@ZnS-PEG nanoparticles can enhance the cancer cell killing efficiency induced by RT, as evidenced by multiple in vitro assays. Owing to the existence of paramagnetic Mn(2+) in the nanoparticle shell, our Au@MnS@ZnS-PEG can be used as a contrast agent for T1-weighted magnetic resonance (MR) imaging, which reveals the efficient accumulation and retention of nanoparticles in the tumors of mice after intravenous injection. Importantly, by exposing tumor-bearing mice that were injected with Au@MnS@ZnS-PEG to X-ray irradiation, the tumor growth can be significantly inhibited. This result shows clearly improved therapeutic efficacy compared to RT alone. Furthermore, no obvious side effect of Au@MnS@ZnS-PEG is observed in the injected mice. Therefore, our work presents a new type of radiosensitizing agent, which is promising for the imaging-guided enhanced RT treatment of cancer.

The interaction at nanobio is a critical issue in designing safe nanomaterials for biomedical applications. Recent studies have reported that it is nanoparticle-protein corona rather than bare nanoparticle that determines the nanoparticle-cell interactions, including endocytic pathway and biological responses. Here, we demonstrate the effects of protein corona on cellular uptake of different sized gold nanoparticles in different cell lines. The experimental results show that protein corona significantly decreases the internalization of Au NPs in a particle size- and cell type-dependent manner. Protein corona exhibits much more significant inhibition on the uptake of large-sized Au NPs by phagocytic cell than that of small-sized Au NPs by nonphagocytic cell. The endocytosis experiment indicates that different endocytic pathways might be responsible for the differential roles of protein corona in the interaction of different sized Au NPs with different cell lines. Our findings can provide useful information for rational design of nanomaterials in biomedical application.

Adhesion is a big concern for the design of Si-based microelectromechanical devices. A ZnO film with nanoscale surface roughness is a promising candidate to decrease adhesion as the protective coating. In this study, the adhesion force of ZnO films prepared by atomic layer deposition (ALD) on a Si (100) substrate was studied. The root-mean-square (RMS) roughness of the ZnO films was in the range of 0.7-4.28 nm, and the contact angle of water was in the range of 85-88°. The adhesion force was measured by atomic force microscopy (AFM) at both low (12%) and high (60%) relative humidities. The results show that the adhesion force decreases as the surface roughness increases. A low adhesion force at high RMS roughness is attributed to the large asperities on the film, and a large adhesion force at high humidity is attributed to the large capillary force. The experimental adhesion force was compared to the force calculated using the Rabinovich model. Although the theoretical value underestimates the experimental value, the proportion of the two components of the adhesion force is clearly shown. At the low humidity, the van der Waals force component differs not greatly with the capillary force component, while at the high humidity, the capillary force component becomes dominant.

Following an inspiration from the fine structure of natural peroxidases, such as horseradish peroxidase (HRP), an artificial peroxidase was constructed through the self-assembly of diblock copolymers and hemin, which formed a functional micelle with peroxidase-like activity. The pyridine moiety in block copolymer poly(ethylene glycol)-block-poly(4-vinylpyridine) (PEG-b-P4VP) can coordinate with hemin, and thus hemin is present in a five-coordinate complex with an open site for binding substrates, which mimics the microenvironment of heme in natural peroxidases. The amphiphilic core-shell structure of the micelle and the coordination interaction of the polymer to the hemin inhibit the formation of hemin μ-oxo dimers, and thereby enhance the stability of hemin in the water phase. Hemin-micelles exhibited excellent catalytic performance in the oxidation of phenolic and azo compounds by H2O2. In comparison with natural peroxidases, hemin-micelles have higher catalytic activity and better stability over wide temperature and pH ranges. Hemin-micelles can be used as a detection system for H2O2 with chromogenic substrates, and they anticipate the possibility of constructing new biocatalysts tailored to specific functions.