Template Precursor Research Articles

Synthesis and application of N–S-doped mesoporous carbon obtained from nanocasting method using bone char as heteroatom precursor and template

We report the synthesis of N–S-doped mesoporous carbon (NSMC) using bone char (BC) as template and heteroatoms precursor. The efficiency of process was evaluated through the synthesis of a material without the use of BC (SC). The materials were properly characterized and textural analysis showed that the BC led to increase of surface area and mesoporous volume for NSMC (568m2g−1 and 0.294cm3g−1) as compared to SC (518m2g−1 and 0.130cm3g−1). The doping of NSMC’s lattice was evaluated from XPS survey spectra. The spectra deconvolution showed that sulfur was incorporated as thiophene and oxidized sulfur, while nitrogen was incorporated as pyridinic, pyrrolic and graphitic, with relative composition of 2.29% and 1.63%, respectively. The Raman and X-ray diffraction analyses showed that the use of BC led to decrease in the intensity of graphitic-band, indicating the doping of carbon lattice. The pHpzc analysis showed that NSMC’s surface has acidic character with pH 3.50, which favored the ibuprofen (IBF) adsorption at pH 4.0, once at this pH value, approximately 87% of IBF species are in protonated form, according to the distribution diagram of species. Adsorption kinetic studies indicated the pseudo-second order model as the best to describe the experimental data. Moreover, adsorption equilibrium studies revealed that the Langmuir model allowed the determination of NSMC’s adsorption capacity (56.78mgg−1); while thermodynamic study showed that the adsorption is a spontaneous and exothermic process. From the results obtained adsorption mechanism of IBF onto the NSMC was proposed.

Porous nanosheet-based hierarchical zinc oxide aggregations grown on compacted stainless steel meshes: Enhanced flexible dye-sensitized solar cells and photocatalytic activity

Porous nanosheet-based hierarchical ZnO aggregations are prepared on compacted stainless steel meshes (CSSMs) using a facile precursor template method. The coverage density and morphology of the film are controlled by the concentration of alkaline in the precursor solution. Relative to the traditional planar substrate, CSSMs with multi-layered structure have larger surface area and higher porosity to capture more light from all directions. The three-dimensional (3D) hierarchical ZnO aggregations assembled by porous nanosheets could take both the advantages of nanosheets and micrometer-sized assemblies. As expected, combining the virtues of ZnO aggregations and CSSMs, the ZnO aggregations/CSSMs structure exhibit the significantly improved conversion efficiency as photoelectrode of flexible dye-sensitized solar cells and photocatalytic performance in the photodegradation of pollutants with a better recyclability. Furthermore, our work would offer idea for the growth of complex 3D hierarchical micro-/nanoarchitecture on the high curvature surface of the substrates.

Effect of calcination temperature on structural properties and photocatalytic activity of Mn-C-codoped TiO2

Mn-C-codoped TiO2 catalysts were synthesized by modified sol-gel method based on the self-assembly technique using polyoxyethylenesorbitan monooleate (Tween 80) as template and carbon precursor and the effect of calcination temperature on their structural properties and photocatalytic activity were investigated. The XRD results showed undoped and Mn-C-codoped TiO2 calcined at 400 oC only include anatase phase and the rutile phase appears when the calcination temperature reached to 600 oC. UV-vis absorption spectroscopy demonstrates that the absorption spectra are strongly modified by the calcination temperature. Moreover, the Mn-C-TiO2 calcined at 400 oC showed the lowest PL intensity due to a decrease in the recombination rate of photogenerated electrons and holes under light irradiation. The photocatlytic activity of Mn-C-codoped TiO2 were evaluated by the degradation of methyl orange (MO) under the simulate daylight irradiation and all the prepared Mn-C-codoped TiO2 samples exhibited high photocatalytic activities for photocatalytic decolorization of methyl orange aqueous solution. At 400 oC, the Mn-C-codoped TiO2 samples showed the highest photocatalytic activity due to synergetic effects of good crystallize ation, appropriate phase composition and slower recombination rate of photogenerated charge carriers, which further confirms the calcination temperature could affect the properties of Mn-C-codoped TiO2 significantly.

Carboxymethylcellulose template synthesis of porous aluminium oxide from hybrid spheres: influence of the degree of substitution and polymerization

Catalytic supports based on aluminum oxide were synthesized by the method of hybrid spheres using carboxymethylcellulose as organic precursor (template) and aluminum nitrate as inorganic precursor. The characterizations were performed by analysis of TG, XRD, FTIR, SEM and N2 physisorption. The study of synthesis indicated that the characteristics of the biopolymer (degree of substitution and polymerization) directly influence on the limit ratio between organic and inorganic precursor in order to observe the formation of the hybrid spheres. The physicochemical properties of the final material (structure by XRD, texture by N2 physisorption and morphology by SEM) showed a direct dependence with the biopolymer properties, indicating the versatility of this synthetic route. FTIR spectra confirm the formation of a hybrid material, comparing the pure CMC spectrum with the solids after drying. N2 adsorption/desorption isotherm and SEM images confirm the formation of highly porous materials with a specific surface area between 50 and 162 m2/g.

Collagen-biomorphic porous carbon nanofiber monoliths: Biosilicification-assisted sustainable synthesis and application in Li-S battery

Monolithic carbon has been synthesized via a sustainable biomimetic route utilizing intrafibrillar silicified collagen sponge as precursor and morphogenesis template. The mineralized silica in the biohybrid prevents collapse of the carbon during pyrolysis. Upon biosilica removal results show that the carbon monoliths inherit the porous fiber structure of the mother collagen. The carbon nanofiber framework facilitates the construction of a high electrical conductive pathway, while the internal spaces developed among the intertwined fibrillar network and pores within nanofiber walls offer room for sulfur storage. The as-obtained carbon-sulfur cathode exhibits an accessible discharge capacity approaching 800[Formula: see text]mAh g[Formula: see text] in Li–S battery.

Co-Doped NiSe nanowires on nickel foam via a cation exchange approach as efficient electrocatalyst for enhanced oxygen evolution reaction

Co-Doped NiSe nanowires supported on nickel foam (NF) were successfully synthesized using NiSe NWs/NF as precursor template in a facile cation exchange approach.

A simple CaCO3-assisted template carbonization method for producing nitrogen doped porous carbons as electrode materials for supercapacitors

A series of nitrogen doped porous carbons are prepared using a simple and economic template carbonization method, in which nano-CaCO3 and ethylenediamine (EDA) and carbon tetrachloride (CTC) serve as a template and nitrogen-containing carbon precursors, respectively. The textural parameters of all the obtained carbon materials are tunable. The porosity and nitrogen content of the nitrogen doped porous carbons strongly depend on the dosage of nano-CaCO3. When the ratio of CaCO3 to the sum weight of EDA and CTC increases from 0.2 to 0.4, the specific surface area increases from 783.72 to 2535.09m2g−1, meanwhile the nitrogen content decreases from 16.13 to 9.47wt%. While when the ratio of CaCO3 to the sum weight of EDA and CTC is moderate, the as-prepared nitrogen doped porous carbons (NPC-0.3) contains as high as 13.45wt% of nitrogen has a balanced specific surface areas of 1276.14m2g−1, exhibits the largest specific capacitance of 226Fg−1 at a current density of 0.1Ag−1 in 1M H2SO4 aqueous electrolyte, due to the co-contribution of double layer capacitance and pseudo-capacitance. Additionally, it shows excellent rate capability (capacitance retention ratio of 58.4% at a current density of 30Ag−1) and good cycling stability (no capacitance decay over 10 000 charge-discharge cycles), making it a promising electrode material for supercapacitors.

Active Sites Implanted Carbon Cages in Core-Shell Architecture: Highly Active and Durable Electrocatalyst for Hydrogen Evolution Reaction.

Low efficiency and poor stability are two major challenges we encounter in the exploration of non-noble metal electrocatalysts for the hydrogen evolution reaction (HER) in both acidic and alkaline environment. Herein, the hybrid of cobalt encapsulated by N, B codoped ultrathin carbon cages (Co@BCN) is first introduced as a highly active and durable nonprecious metal electrocatalysts for HER, which is constructed by a bottom-up approach using metal organic frameworks (MOFs) as precursor and self-sacrificing template. The optimized catalyst exhibited remarkable electrocatalytic performance for hydrogen production from both both acidic and alkaline media. Stability investigation reveals the overcoating of carbon cages can effectively avoid the corrosion and oxidation of the catalyst under extreme acidic and alkaline environment. Electrochemical active surface area (EASA) evaluation and density functional theory (DFT) calculations revealed that the synergetic effect between the encapsulated cobalt nanoparticle and the N, B codoped carbon shell played the fundamental role in the superior HER catalytic performance.

Macroporous alumina with cellular interconnected morphology from emulsion templated polymer composite precursors

Macroporous polymer composites with included alumina particles were prepared via an emulsion templating procedure by photopolymerising the monomer containing continuous phase. Methyl methacrylate and multifunctional acrylate monomer Sartomer SR 492 were used for the polymer matrix. Composites with open porous cellular morphology with cavities around 15μm were obtained and further processed by a calcination and sintering process to form alumina ceramic material with the same morphology as the polymer composite precursors. Emulsion composition was optimised in order to obtain monolithic type of the final material with macropores on a micrometer scale connected by a number of interconnecting channels. Mechanical and thermal properties both of precursor composites and ceramic materials were evaluated.

In situ synthesis of Ti3+ self-doped mesoporous TiO2 as a durable photocatalyst for environmental remediation

This study developed a facile approach for in situ synthesis of a Ti3+ self-doped mesoporous TiO2 photocatalyst by an evaporation-induced self-assembly method using TiCl3, water, and F127 as the titanium precursor, solvent, and soft template agent, respectively. The as-prepared samples were investigated by X-ray diffraction, N2 adsorption-desorption measurements, ultraviolet-visible diffuse reflectance spectroscopy, electron paramagnetic resonance, and transmission electron microscopy. The influence of different reaction parameters such as the dosage of F127 and calcination temperature on the photocatalytic performance of the resulting products was evaluated. The optimized product exhibited high photocatalytic activity and stability in the oxidation of nitric oxide in air and photocatalytic degradation of methylene blue. The excellent photocatalytic performance of the Ti3+ self-doped mesoporous TiO2 photocatalyst is attributed to the cooperation between the mesoporous structure and self-doped Ti3+ enhancing light absorption and effectively suppressing the recombination of photogenerated electrons and holes.

Solid-state grinding synthesis of ordered mesoporous MgO/carbon spheres composites for CO2 capture

Ordered mesoporous MgO/carbon spheres composites were synthesized via solid-state grinding method, in which Pluronic F127, phenolic resol and magnesium nitrate were used as the template, carbon source and guest precursor respectively. The resultant materials showed a spherical morphology with a uniform diameter of 200nm, body-centered cubic mesostructure of 2.6–3.2nm in pore diameter. The material with the content of 7.9wt% MgO exhibited the best CO2 adsorption capacity of 3.08mmolg−1 at 273K, 1.2bar.

Synthesis of Perforated Polygonal Cobalt Oxides usinga Carbon Nanofiber Template

Perforated polygonal cobalt oxide () is synthesized using electrospinning and a hydrothermal method followed by the removal of a carbon nanofiber (CNF) template. To investigate their formation mechanism, thermogravimetric analysis, field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy are examined. To obtain the optimum condition of perforated polygonal , we prepare three different weight ratios of the Co precursor and the CNF template: sample A (Co precursor:CNF template- 10:1), sample B (Co precursor:CNF template-3.2:1), and sample C (Co precursor:CNF template-2:1). Among them, sample A exhibits the perforated polygonal with a thin carbon layer (5.7-6.2 nm) owing to the removal of CNF template. However, sample B and sample C synthesized perforated round and destroyed powders, respectively, due to a decreased amount of Co precursor. The increased amount of the CNF template prevents the formation of polygonal . For sample A, the optimized weight ratio of the Co precursor and CNF template may be related to the successful formation of perforated polygonal . Thus, perforated polygonal can be applied to electrode materials of energy storage devices such as lithium ion batteries, supercapacitors, and fuel cells.

Measurement artifacts identified in the UV–vis spectroscopic study of adduct formation within the context of molecular imprinting of naproxen

The ultraviolet–visible spectroscopy has been assessed as a technique for the evaluation of the strength of template–precursor adduct in the development of molecular imprints of the non-steroidal anti-inflammatory drug naproxen (NAP). The commonly employed approach relies on the collection of UV spectra of drug+precursor mixtures at different proportions, the spectra being recorded against blanks containing the same concentration of the precursor. The observation of either blue or red band-shifts and abatement of a major band are routinely attributed to template–precursor adduct formation. Following the described methodology, the precursors 1-(triethoxysilylpropyl)-3-(trimethoxysilylpropyl)-4,5-dihydroimidazolium iodide (AO-DHI+) and 4-(2-(trimethoxysilyl)ethyl)pyridine (PETMOS) provoked a blue-shift and band abatement effect on the NAP spectrum. Molecular dynamics simulations indicated a reasonable affinity between NAP and these precursors (coordination numbers 0.33 for AO-DHI+ and 0.18 for PETMOS), hence showing that NAP-precursor complexation is in fact effective. However, time dependent density functional theory (TD-DFT) calculations of the spectra of both free and precursor-complexed NAP were identical, thus providing no theoretical basis for the complexation-induced effects observed. We realized that the intense spectral bands of AO-DHI+ and PETMOS (at around 265nm) superimpose partially with the NAP bands, and the apparent “blue-shifting” in the NAP spectra when mixed with AO-DHI+ and PETMOS was in this case a spurious effect of the intense background subtraction. Therefore, extreme care must be taken when interpreting other spectroscopic results obtained in a similar fashion.

Mesoporous carbon spheres: Synthesis, surface modification and neutral red adsorption

A simple ultrasonic method of preparing porous carbon spheres without using a solvent was presented. Furfuryl alcohol acted dual functions as carbon sources and solvent, silica nanoparticles as template precursor, and oxalic acid as homogeneous catalyst. Effects of different oxidants (H2O2 and HNO3) on structural parameters, morphologies, and dye adsorption properties of carbon samples were studied. Results showed that specific surface areas and total pore volumes of carbon spheres increased with H2O2 treatment, whereas surface area and pore volume of carbon spheres decreased after HNO3 oxidation. Oxidized mesoporous carbon sphere exhibited better adsorption capacity and adsorption affinity for neutral red dye than pristine carbon.

Pig bones derived N-doped carbon with multi-level pores as electrocatalyst for oxygen reduction

In this work, a N-doped highly porous carbon material with multi-level pores and high activity for oxygen reduction reaction (ORR) is successfully prepared by carbonizing pig bones instead of separated carbon/nitrogen-containing and template precursors. The N-doped porous carbon material has high specific surface area of ca. 562.6 m2 g−1. Due to its high surface area and N-doped active sites, the ORR activity of obtained carbon in alkaline media is higher than that of commercial Pt/C catalyst (10 wt.%). In addition, it shows a higher methanol tolerance than Pt/C catalyst and long term-operating stability, rendering it as promising ORR catalyst material for fuel cells.

Thin‐Sheet Carbon Nanomesh with an Excellent Electrocapacitive Performance

A facile yet effective chemical vapor deposition (CVD) method to prepare carbon nanomesh (CNM) with MgAl‐layered double oxides (LDO) as sacrificial template and ferrocene as carbon precursor is reported. Due to the combined effect of the LDO template and organometallic precursor, the as‐made hexagonal thin‐sheet CNM features a hierarchical pore system consisting of micropores and small mesopores with a size range of 1–6 nm, and a great number of random large mesopores with a pore size of 10–50 nm. The density, geometry, and size of the pores are strongly dependent on the CVD time and the annealing conditions. As supercapacitor electrode, the CNM exhibits an enhanced capacitance, high rate capability, and outstanding cycling performance with a much‐shortened time constant. The excellent capacitive performance is due to the presence of the large mesopores in the 2D CNM, which not only offer additional ion channels to accelerate the diffusion rate across the thin sheets but also help to make efficient use of the oxygen functional groups at the edges of large mesopores to increase the pseudocapacitance contribution.

MOF derived porous carbon supported Cu/Cu2O composite as high performance non-noble catalyst

Porous carbon supported copper composite (Cu/Cu2O/C) was synthesized with a facile, low cost and novel method and used as non-noble-metal catalyst for reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) by NaBH4. In the synthetic strategy, metal organic framework Cu3(BTC)2 (also denoted as HKUST-1) was used as both sacrificial template and copper precursor, and phenol formaldehyde resin as carbon precursor. The catalytic Cu/Cu2O nanoparticles (Cu/Cu2O NPs) about 40 nm-in-diameter distributed uniformly both on the internal and external surface of the porous carbon flakes, and took up 33.38–37.56 wt% of the Cu/Cu2O/C composite. Compared with noble metal catalysts, the prepared composite showed comparable high catalytic activity, which was mainly due to their porous structure facilitating diffusion of reactants and products, and the high dispersion of accessible catalytic Cu/Cu2O NPs on porous carbon. Moreover, the synthesized catalyst can be reused for at least five cycles due to its good stability. These results confirmed that the as-prepared Cu/Cu2O/C is promising candidate to replace noble metal for catalytic application.

Dopamine derived nitrogen-doped carbon sheets as anode materials for high-performance sodium ion batteries

Designed as an anode material for sodium ion batteries, nitrogen-doped carbon sheets (NCSs) were successfully synthesized using graphene and dopamine as template and carbon precursor, respectively. The NCSs demonstrate high reversible capacity and excellent rate performance, delivering a high reversible capacity of 382mAhg−1 at 50mAg−1 after 55 cycles. Even up to 10Ag−1, a rate capacity of 75mAhg−1 can be obtained. Furthermore, NCSs also have remarkable cycling stability with specific capacity of 165mAhg−1 after 600 cycles (under 200mAg−1). The excellent performance of NCSs can be ascribed to the nitrogen-doped two-dimension sheet structure.

Rapid functionalization of as-synthesized KIT-6 with nickel species occluded with template for adsorptive desulfurization

Nickel-containing mesoporous silica, Ni-KIT-6, was prepared by directly grinding nickel nitrate into the as-synthesized KIT-6 occluded with template for adsorptive desulfurization of fuels. The obtained materials were well-characterized by N2 adsorption, XRD, HRTEM, H2-TPR, FT-IR, XPS and TG/DTG. The results reveal that the abundant silanols, as well as the confined space between silica walls and template in as-synthesized KIT-6 are highly efficient in dispersing large amount of nickel oxide in the channels of mesoporous silica. Compared with the material synthesized using calcined KIT-6, Ni-KIT-6 demonstrates extremely smaller Ni particles on the support, stronger interaction of Ni with silica matrix and higher content of active Ni0 in the KIT-6. As a result, the adsorptive desulfurization performance of Ni-KIT-6, both in commercial and model fuels was enhanced. The present strategy not only saves time and energy, but also allows template removal and precursor conversion in one step instead of repeated calcinations in conventional methods. After regeneration of spent sorbent, approximately 100% of adsorption capacity was recovered.

Synthesis, conversion, and comparison of the photocatalytic and electrochemical properties of Na2Ti6O13 and Li2Ti6O13 nanobelts

Single-crystalline Li2Ti6O13 nanobelts have been prepared from Na2Ti6O13 nanobelts as the precursor templates via sodium/lithium ion-exchange in molten LiNO3 at 400°C for 10h for the first time. Both Na2Ti6O13 and Li2Ti6O13 nanobelts are also characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and high-resolution transmission electron microscopy (HRTEM). Our experiments show that Na2Ti6O13 and Li2Ti6O13 nanobelts exhibit higher photocatalytic efficiency than their bulk counterparts for the degradation of Rhodamine B (RhB) under ultraviolet light (UV) irradiation. In comparison to Na2Ti6O13 nanobelts, Li2Ti6O13 nanobelts exhibit lower photocatalytic efficiency, which may result from the expansion of tunnel space in Li2Ti6O13. However, the electrochemical Li insertion–extraction experiments reveal that the stable reversible discharge capacity of Li2Ti6O13 nanobelts is higher than that of Na2Ti6O13 nanobelts. Moreover, our results also indicate that the reversible discharge capacities of Na2Ti6O13 and Li2Ti6O13 nanobelts are slightly less than that of their bulk counterparts.