Assistance Of Template Research Articles

Synthesis of nitrogen enriched porous carbon sponge with the assistance of hard template and physical activation for highly efficient CO2 adsorption

Porous carbons are attractive materials for CO2 capture due to their unique properties. In the current work, N-doped porous carbon sponge (NDPCS) was synthesized with a combined hard template and CO2 activation method, and the applications in CO2 adsorption were also studied. Correlations between synthesis parameters and the product’s morphology were revealed, and effects of the activation conditions on N content and textural properties were analyzed. CO2 adsorption performances of the NDPCS were also thoroughly investigated. The influences of various physicochemical properties on adsorption properties were discussed. CO2 uptake at 25 °C and 1 bar was relatively low (2.16–2.50 mmol/g). However, NDPCS-3–3 showed impressively high adsorption efficiency of 1.63 (mmol/g)/(100 m2/g), much better than some of the best performing samples from reported works. The superior performances were attributed to the combined effects of abundant ultramicropores and enriched N-doping. The current work showed that the NDPCS had great potential for applications in CO2 capture.

Broad-band-enhanced plasmonic random laser in silver nanostar arrays

As a novel optical device, the plasmonic random laser has unique working principle and emission characteristics. However, the simultaneous enhancement of absorption and emission by plasmons is still a problem. In this paper, we propose a broad-band-enhanced plasmonic random laser. Two-dimensional silver (Ag) nanostar arrays were prepared using a bottom-up method with the assistance of self-assembled nanosphere templates. The plasmon resonance of Ag nanostars contributes to the pump light absorption and photoluminescence (PL) of RhB. Coherent random lasing was achieved in RhB@PVA film based on localized surface plasmon resonance (SPR) dual enhancement and scattering feedback of Ag nanostars. Ag nanostars prepared with different nanosphere diameters affect the laser emission wavelength. In addition, the random laser device achieves wavelength tunability on a flexible substrate under mechanical external force.

Selective removal of acid sites in mordenite with the assistance of tetraethylammonium bromide for high performing dimethyl ether carbonylation reaction

The distribution of acid sites in Mordenite (MOR) is crucial for its carbonylation performance. In this paper, MOR was subjected to acid treatment to selectively remove acid sites in 12 member-ring (MR) with the assistance of tetraethylammonium bromide (TEABr) used during synthesis process. The impact of acid treatment on structure, morphology, framework atoms and acidity were systematically studied. The characterization results indicated that the structure of the samples was only slightly impacted while the mesopore volume slightly increased. Due to the excessive removal of acid sites, the sample treated by nitric acid (0.1 mol/L) exhibited lower carbonylation activity whether with or without the protection of templates. However, the acid sites in the 12 MR were selectively removed in the citric acid treatment process by two different ways: the etching effect of H+ and the complexation of citric ions. The protection effect of templates for the acid sites in 8 MR was remarkable. Therefore, selective removal of acid sites in 12 MR was successful realized with assistance of template, leading to considerable improvements in activity for DME carbonylation reaction.

Synthesis of highly porous N-doped hollow carbon nanospheres with a combined soft template-chemical activation method for CO2 capture

In the present study, N-doped hollow carbon nanospheres (NHCNs) were synthesized with a combined soft template-chemical activation method. Spherical hollow hydrochar was prepared from glucose with the assistance of dual soft templates, and was then chemically activated with KHCO3 and urea to produce the NHCNs. Effects of urea addition and activation temperature on the NHCNs’ physicochemical properties were revealed. The NHCNs were endowed with rich N-doping and developed porosity. The sample activated at 800 °C (NHCN2800) showed an impressive specific surface area of 3234 m2/g. The proposed method could also be extended to the synthesis of N, S co-doped hollow carbon nanospheres. We then investigated CO2 adsorption performances of the NHCNs. At 25 °C and 1 bar, the best CO2 uptake of the NHCNs was 4.36 mmol/g; at 20 bar, it increased to a record high level of 23.62 mmol/g. Correlations between textural characteristics/N-doping and CO2 adsorption at 1/20 bar were analyzed and discussed. The current study indicated that the obtained NHCNs had great potential for applications in both pre- and post-combustion CO2 capture.

Helicity-modulated remote C-H functionalization.

Remote C-H functionalization is highly important for the conversion and utilization of arenes, but the conventional routes are comprehensively developed with the assistance of transition metal catalysts or templates. We report a facile metal/template-free electrochemical strategy for remote C-H functionalization in a helical system, where aromatic or aliphatic hydrogen act as a directing group to promote the alkoxylation at the opposite site of the helical skeleton by generating a unique helical "back-biting" environment. Such helicity-modulated C-H functionalization is prevalent for carbo[n]helicenes (n=6 to 9, primitive or substituted) and hetero[6]helicenes and also occurs when the aryl hydrogen on the first position is replaced by a methyl group or a phenyl group. Thus, the relatively inert helicene skeleton can be precisely furnished with a rich array of alkoxy pendants with tunable functional moieties. Notably, the selective decoration of a methoxy group on N-methylated aza[6]helicene close or distant to the nitrogen atom leads to distinct luminescence variation upon changing the solvents.

Enhanced desalination performances by using porous polyaniline-activated carbon composite flow-electrodes in capacitive deionization system

Flow electrodes capacitive deionization (FCDI) is a promising CDI variant, and has been used in various fields like brackishwater desalination and nutrients recovery. Activated carbon (AC), a prevalent FCDI electrode, suffers from low ion adsorption capacity, poor electric conductivity, and large viscosity, which restrict their large-scale applications. In this study, situ polymerization was utilized to prepare porous polyaniline and activated carbon composite (pPANI-AC) electrode with the assistance of ice template. This innovative electrode took advantages of the pseudocapacitive effects of porous polyaniline and the ion channels was increased by exposing the pores and surface of the porous activated carbon. The new composite electrode has an increase in specific surface area from 213.5 m2 g−1 to 616.1 m2 g−1, and an increase in capacitance from 93 to 178 F g−1, and the viscosity flow electrodes decreases from 127 to 21 Pas. Reduced viscosity and intrinsic impedance of the flow electrode result in an increase in flow electrode conductivity and ionic capacity of the FCDI system that has a 70 % increase in desalination capacity. This study developed a low-cost and environmentally friendly active material for high-efficient flowable electrodes, which will pave way for the real applications of FCDI technology.

Dual template induced assembly of 2D nanosheets to 3D porous Mo2C/NiFe-NC networkers for electromagnetic wave absorption

Developing high-performance materials with ultrathin matching thickness for electromagnetic wave absorption (EMW) is essential for the commercialization of electromagnetic devices, but it is still formidably challenging. In this work, Mo2C/NiFe-NC networker with small Mo2C grains, NiFe alloy coated by graphitized carbon (NiFe-NC), and N-doped carbon matrix are constructed by free-drying and dual template strategy. With the assistance of hard template (salt, NaCl)) and soft template (urea), the ultrathin 2D layered carbon nanosheets produced by pyrolysis are assembled into a 3D hierarchical porous network. The designed Mo2C/NiFe-NC networker exhibits a hierarchical porous structure, 3D network skeleton, heterogeneous interface, abundant heteroatom doping, and magnetic NiFe alloy, which inherits good dielectric loss (dipole polarization, interfacial polarization, and conduction loss), magnetic loss (natural resonance and exchange resonance) and considerable impedance matching characteristics. Impressively, the well-designed Mo2C/NiFe-NC networker enables a reflection loss (RL) value of −51.56 dB at an ultrathin matching thickness of 1.4 mm. Furthermore, the effective absorption bandwidth (EAB, RL ≤ −10 dB) is up to 3.7 GHz. Importantly, the EAB in the matching thickness range of 1–5 mm is as high as 14.6 GHz, covering the entire C-band, X-band, and Ku-band. This work may open a key avenue for high-performance EMW absorption materials via a dual template assistance strategy.

A Metal‐Free Mesoporous Carbon Dots/Silica Hybrid Type I Photosensitizer with Enzyme‐Activity for Synergistic Treatment of Hypoxic Tumor

AbstractAs a less O2‐dependent photodynamic therapy (PDT), type I PDT is an effective approach to overcome the hypoxia‐induced low efficiency against solid tumors. However, the commonly used metal‐involved agents suffer from the long‐term biosafety concern. Herein, a metal‐free type I photosensitizer, N‐doped carbon dots/mesoporous silica nanoparticles (NCDs/MSN, ≈40 nm) nanohybrid with peroxidase (POD)‐like activity for synergistic PDT and enzyme‐activity treatment, is developed on gram scale via a facile one‐pot strategy through mixing carbon source and silica precursor with the assistance of template. Benefiting from the narrow bandgap (1.92 eV) and good charge separation capacity of NCDs/MSN, upon 640 nm light irradiation, the excited electrons in the conduction band can effectively generate O2•− by reduction of dissolved O2 via a one‐electron transfer process even under hypoxic conditions, inducing apoptosis of tumor cells. Moreover, the photoinduced O2•− can partially transform into more toxic •OH through a two‐electron reduction. Moreover, the POD‐like activity of NCDs/MSN can catalyze the endogenous H2O2 to •OH in the tumor microenvironment, further synergistically ablating 4T1 tumor cells. Therefore, a mass production way to synthesize a novel metal‐free type I photosensitizer with enzyme‐mimic activity for synergistic treatment of hypoxic tumors is provided, which exhibits promising clinical translation prospects.

Nitrogen-doped meso-macroporous carbon from waste asphalt as high-performance anode materials for alkali-ion batteries

Rechargeable alkali-ion (Li+, Na+, and K+) batteries with high conversion efficiency have attracted much attention for portable and sizeable energy storage. Deriving valuable battery materials from valueless waste materials is highly desirable to meet the surging demand of energy storage. However, waste-derived carbon materials often show low specific capacity and poor reversibility due to untamed physiochemical properties. In this paper, nitrogen doped meso-macroporous carbon (NMPC) materials are produced from waste asphalt with the assistance of nano-Fe2O3 template and melamine modification. The products show interconnected three-dimensional meso-macroporous structures and tunable nitrogen contents. As an anode material for Li-ion batteries, the NMPC with optimum nitrogen content delivers a reversible capacity of 602.3 mA h g−1 at 0.2 A g−1. Furthermore, it also discharges a reversible capacity of 210.8 mA h g−1 after 200 cycles and 201.5 mA h g−1 after 500 cycles for Na-ion batteries and K-ion batteries, respectively. The excellent and versatile electrochemical properties enable the concept of waste recovery and resource utilization, which can be used for the manufacture of environmentally friendly energy storage systems.

Finite Element Analysis and Transiliac-Transsacral Screw Fixation for Posterior Pelvic Ring with Sacrum Dysplasia.

Posterior pelvic ring sacroiliac screws are preferred by clinicians for their good biomechanical performance. However, there are few studies on mechanical analysis and intraoperative screw insertion of the dysplastic sacrum and sacroiliac screw. This study investigated the biomechanical performance of oblique sacroiliac screws (OSS) in S1 combined with transiliac-transsacral screws (TTSs) in S2 for pelvic fracture or sacroiliac dislocation with dysplastic sacrum and evaluated the safety of screw placement assisted by the navigation template. Six models were established, including one OSS fixation in the S2 segment, one transverse sacroiliac screw (TSS) fixation in the S2 segment, one TTS fixation in the S2 segment, one OSS fixation in the S1 and S2 segments, one OSS fixation in the S1 segment and one TSS fixation in the S2 segment, one OSS fixation in the S1 segment and one TTS fixation in the S2 segment. Then, finite element analysis (FEA) was performed. Twelve dysplastic sacrum patients with pelvis fracture or sacroiliac dislocation underwent OSS insertion in the S1 combined with TTS insertion in the S2 under the assistance of the patient-specific locked navigation template. Grading and Matta scores were evaluated after surgery. In the one-screw fixation group, the vertical displacements of the sacrum surface of S2 OSS, S2 TSS and S2 TTS were 1.23, 1.42, and 1.22 mm, respectively, and the maximum stress of screw were 139.45 MPa, 144.81 MPa, 126.14 MPa, respectively. In the two-screw fixation group, the vertical displacements of the sacrum surface of the S1 OSS + S2 OSS, S1 OSS + S2 TSS and S1 OSS + S2 TTS were 0.91, 1.06, and 0.75 mm, respectively, and the maximum stress of screw were 149.26 MPa, 167.13 Pa, 136.76 MPa, respectively. Clinically, a total of 12 TTS and OSS were inserted under the assistance of navigation templates, with a surgical time of 55 ± 7.69 min, bleeding of 57.5 ± 18.15 ml and radiation times of 14.5 ± 4.95. One of the TTS and one of the OSS were grade 1, and the other screws were grade 0. The Matta scores of nine patients were excellent, and three patents were good. OSS in the S1 combined with TTS in the S2 had the best mechanical stability in six models, and it is safe for screw insertion assisted by the patient-specific locked navigation template.

Bionic Construction of Helical Bi2 O3 Microfibers for Highly Efficient CO2 Electroreduction.

Helical Bi2 O3 microfibers (HBM) were prepared with the assistance of cotton template through a simple heating treatment in air. This twisted structure induced the lattice strains, enriched the oxygen vacancies of Bi2 O3 , and promoted the sufficient exposure of active sites simultaneously, thus performing outstanding activity and selectivity as catalyst for CO2 electroreduction to formate. The faradaic efficiency (FE) of formate reached 100.4±1.9 % at -0.90 V vs. reversible hydrogen electrode (RHE) in an H-cell, and the partial current density was boosted to 226 mA cm-2 with FEformate of 96 % at -1.08 V vs. RHE in a flow cell. This work may open a new era for construction of metal oxide fibers by bionic strategy as high-performance electrocatalysts.

Biomass CQDs derivate carbon as high-performance anode for K-ion battery

Carbon quantum dots (CQDs) as a multifunctional carbon nanomaterial have drawn great attention in the field of energy attribute to quantum size, various functional groups and unique physicochemical properties. In this work, the CQDs were prepared from soybean by a simple hydrothermal method, then further pyrolyzed into honeycomb carbon (HC), spherical pore carbon (SC) and bulk porous carbon (BC) with the assistance of templates, respectively. As the anode materials in potassium ion battery (PIBs), HC delivered a high specific capacity of 280.5 mAh g−1 at 0.1 A g−1 and a superior rate performance (136 mAh g−1 at 5 A g−1), ascribing to its abundant surface active sites of potassium ion storage and special structures conducive to potassium ion diffusion. This study provides an excellent anode for PIBs from a simple route to construct CQDs-derived carbon.

"Rim-Differentiated" Pillar[6]arenes.

A "rim-differentiated" pillar[6]arene (RD-P[6]) was obtained successfully, with the assistance of a dimeric silver trifluoroacetate template, among eight different constitutional isomers in a direct and regioselective manner. The solid-state conformation of this macrocycle could switch from the 1,3,5-alternate to a truly rim-differentiated one upon guest inclusion. This highly symmetric RD-P[6] not only hosts metal-containing molecules inside its cavity, but also can form a pillar[6]arene-C60 adduct through co-crystallization on account of donor-acceptor interactions. The development of synthetic strategies to desymmetrize pillararenes offers new opportunities for engineering complex molecular architectures and organic electronic materials.

“Rim‐Differentiated” Pillar[6]arenes

AbstractA “rim‐differentiated” pillar[6]arene (RD‐P[6]) was obtained successfully, with the assistance of a dimeric silver trifluoroacetate template, among eight different constitutional isomers in a direct and regioselective manner. The solid‐state conformation of this macrocycle could switch from the 1,3,5‐alternate to a truly rim‐differentiated one upon guest inclusion. This highly symmetric RD‐P[6] not only hosts metal‐containing molecules inside its cavity, but also can form a pillar[6]arene‐C60 adduct through co‐crystallization on account of donor‐acceptor interactions. The development of synthetic strategies to desymmetrize pillararenes offers new opportunities for engineering complex molecular architectures and organic electronic materials.

A facile template-assisted synthesis of large-scale Bi2O3 nanotube arrays for self-powered UV photodetector

Large-scale Bi2O3 nanotubes (NTs) arrays were successfully synthesized on ITO substrate with the assistance of ZnO nanorods template at room temperature. The as-synthesized highly orientated Bi2O3 NTs with an average diameter of ∼95 nm were well distributed throughout the entire substrate. Moreover, Bi2O3 NTs were employed to construct the ultraviolet photodetector (UVPD). Received to UV irradiation, the Bi2O3 NTs UVPD displayed a high average current density of 40.4 μA/cm2, coupled with fast average rise time of ∼28.8 ms and decay time of ∼40.9 ms. Furthermore, the Bi2O3 NTs UVPD could carry out accurate UV detection without external bias as well as maintain good stability and repeatability. Additionally, the UV detection mechanism of the as-assembled Bi2O3 NTs UVPD was also discussed.

Strategy for boosting Co-Nx content for oxygen reduction reaction in aqueous metal-air batteries

Electrocatalyst is the pivotal component promoting the kinetics of oxygen reduction reaction in aqueous metal-air batteries. However, the content of increased bond as the active species is usually limited by the metal loading, tiny pore canal, insufficient nitrogen further restraining the electrocatalytic effectiveness of single-atom catalysts in oxygen reduction reaction (ORR). Herein, Co, N-dual doped carbon (Co/NNC) is prepared by a versatile strategy of the combination approach of SiO2 template with extra nitrogen source. Based on ZIF-67 prepared with the assistance of SiO2 template, the extra nitrogen source was introduced in the high-temperature pyrolysis procedure. The material characterizations of XRD, SEM, HRTEM, BET, Raman and XPS are conducted to synthetically analyze the functional role of extra nitrogen source. Moreover, the Co/NNC with increased Co-Nx active sites is employed into two aqueous metal-air batteries of Zn-air and Mg-air batteries, which exhibits excellent performances especially in the aspects of discharge specific capacity, discharge stability and power density.

Template assisted preparation of silicone (polydimethylsiloxane) elastomers and their self-cleaning application.

The formation of self-cleaning functions on silicone elastomers is crucial for practical applications but still challenging. In this study, superhydrophobic silicone elastomers (SHSEs) with a 3D-hierarchical microstructure were achieved during the curing process with the assistance of a homemade template. The micro–nano structure formed by the assistance of the template makes the silicone elastomer surface achieve robust superhydrophobicity with a WCA at ∼163°, which can easily self-clean, removing surface contamination. Also, TiO2 particles transferred from the template endow the surface with photocatalytic functions, which can degrade organic pollutants under UV irradiation. After sandpaper abrasion, the formed SHSE can maintain its excellent hydrophobicity and show liquid repellency to wine and coffee droplets. The SHSEs with self-cleaning functions have promising applications in water treatment, medical facilities, and wearable devices.

Nanoarchitectonics for conductive polymers using solid and vapor phases.

Conductive polymers have been extensively studied as functional organic materials due to their broad range of applications. Conductive polymers, such as polypyrrole, polythiophene, and their derivatives, are typically obtained as coatings and precipitates in the solution phase. Nanoarchitectonics for conductive polymers requires new methods including syntheses and morphology control. For example, nanoarchitectonics is achieved by liquid-phase syntheses with the assistance of templates, such as macromolecules and porous materials. This minireview summarizes the other new synthetic methods using the solid and vapor phases for nanoarchitectonics. In general, the monomers and related species are supplied from the solution phase. Our group has studied polymerization of heteroaromatic monomers using the solid and vapor phases. The surface and inside of solid crystals were used for the polymerization with the diffusion of the heteroaromatic monomer vapor. Our nanoarchitectonics affords to form homogeneous coatings, hierarchical structures, composites, and copolymers for energy-related applications. The concepts using solid and vapor phases can be applied to nanoarchitectonics for not only conductive polymers but also other polymers toward a variety of applications.

Ascorbic acid-assisted hydrothermal route to create mesopores in polymeric carbon nitride for increased photocatalytic hydrogen generation

The facile synthesis of mesoporous polymeric carbon nitride (PCN) can enlarge the surface area and provide mass transport channels, which thus potentially boosts its photocatalytic H2 generation. However, the formation of mesopores in PCN are mainly relying on the hard and soft templates with tedious operations, and it remains a grand challenge in preparing mesoporous PCN without the assistance of templates. Herein we report on an ascorbic acid-assisted hydrothermal route to effectively create the mesoporous in bulk PCN. The mesopores thus formed a typical IV isotherm with an H3 hysteresis loop, and have a pore size distribution of ∼3.8 nm. Moreover, the crystallinity of mesoporous PCN was improved with ascorbic acid-assisted hydrothermal treatment. Meanwhile, ascorbic acid can be converted to carbon materials under hydrothermal conditions. As a result, an increased photocatalytic H2 generation was realized under visible light exposure. The highest H2 generation rate is up to 26.8 μmol h−1 for Pt/CN-A10%, near 10 times higher than that of Pt/PCN (2.7 μmol h−1). This work highlights the effectiveness of organic acid-assisted hydrothermal treatment for synthesizing mesoporous PCN for increased photocatalytic performance.

Green and ultrafast preparation of layered CuO nanoparticles and its ultrahigh-performance ethanol sensing application

Accurately controlling and rapidly fabricating ultra-sensitive micro/nano-scale CuO sensors without the assistance of any assembly template or organic solvent was a major challenge recently. In this work, a flower-like Cu3(PO4)2 precursor was prepared within 10 s by an ultrasonic spray method, and then the precursor was soaked in 80 °C NaOH solutions to rapidly prepare CuO material with different microscopic morphologies. Through testing the sensing performance of CuO products for 400 ppm ethanol, it was found that the highest sensitivity of CuO nanoparticles prepared by this method reached 135 (response/recovery time was 173 s/118 s respectively), which was much higher than CuO nanorods and CuO nanosheets, and the sensitivity for 10 ppm ethanol reached 19.9, indicating that the product had an ultra-high sensitivity and an ultra-low detecting limit. At the same time, the optimal detecting temperature has been reduced to 225 °C, while still retaining excellent selectivity, reproducibility, and stability. Furthermore, the whole process only took several minutes, instead of several-day reacting process in the previous work. It provided a way for the rapid fabrication of ultra-sensitive CuO sensor in a green strategy.