Synthesis Of Carbon Research Articles

Sustainable Hard Carbon as Anode Materials for Na‐Ion Batteries: From Laboratory to Upscaling

Sodium‐ion batteries (NIBs) are an alternative to lithium‐ion batteries (LIBs), particularly in applications where cost, availability, and sustainability are more critical. Hard carbon is emerging as a promising anode material for NIBs, however, the scale up remains in developmental stages. In this study, we focus on the development and potential upscaling of sustainable hard carbon materials as anodes for NIBs. The synthesis of hard carbon starts from D‐glucose, a scalable and environmentally benign precursor. A facile process combining hydrothermal carbonisation and subsequent pyrolysis at 1500°C allows the hard carbon to become an industrially viable material. The resulting hard carbon demonstrates competitive performance metrics including a high initial Coulombic efficiency, high reversible capacity, long‐term cycling stability, and rate capability. This study concludes with a discussion of the techno‐economic analysis of adopting such sustainable materials in the battery industry, highlighting the potential for significant advancements in energy storage technologies.

Application of KF/waste glass catalyst in the synthesis of fatty acid esters under pressurized conditions without glycerol generation

In this study, the efficiency of applying the KF/waste glass catalyst was tested in the transesterification of crambe oil under pressurized conditions for the synthesis of esters and glycerol carbonate (GLC). For this, a miscella pressurized extraction was used. The influence of temperature on different residence times was evaluated, and to verify the effect of the catalyst on the process, non-catalytic reactions were conducted. In reactions without the use of catalyst, a temperature of 250 °C was required to obtain >90 % esters yield. In the catalytic reactions, the operating conditions were reduced to 225 °C, to obtain ∼96 % esters yield, also providing the synthesis of a greater quantity of GLC, and a glycerol-free sample. The wet modification of powdered glass waste with KF results in the K2SiF6, NaF, CaF2, and KCaF3 phases. The laser-induced breakdown spectroscopy analyses showed the presence of fluorinated compounds in the catalyst. Furthermore, calcium and sodium ions from the glass waste matrix support were the source for the crystalization of K2SiF6/CaF2/KCaF3 and NaF phases, respectively. The catalyst showed a good catalytic activity, promoting high ester and GLC formation at 225 °C, 10 min and 10 MPa, remaining with good performance even after 8h of reaction, but it is important to mention that the stability of the catalyst needs to be improved due to the leaching of K to Ca.

Synthesis of Calcium Carbonate from Orange Peel Waste Extract: A Mechanistic Investigation

The present work reports the mechanism and synthesis of calcium carbonate (CaCO3) formation from orange peel, which is one of the most common agriculture waste generated throughout the globe. The zest of oranges was co-distilled with distilled water to separate the essential oil content. Further, the residue was washed twice with distilled water to get the desired extract. For the green synthesis of CaCO3, a saturated solution of calcium nitrate tetrahydrate (Ca(NO3)2·4H2O) was mixed thoroughly with orange peel extract in the 1:3 proportion. This solution was kept on magnetic stirrer while maintaining temperature at 85˚C, heated at 100˚C for 13 h which was further annealed at 300˚C, 500˚C and 700˚C. X-ray diffraction (XRD) shows the presence of calcite phase corresponding to CaCO3. Fourier transform infrared spectra (FTIR) exhibits the bands corresponding to Ca-O, C-O and vibrations of CO3-2 bonds whereas UV–Visible spectroscopy shows the optical behavior of CaCO3. The qualitative analysis of orange peel extract as well as the black-brown gel formed as a result of sol–gel synthesis method was examined using Gas Chromatography & Mass Spectrometry (GCMS). It revealed the presence of acidic groups (2,3-butanediol & 1,4-benzenediol) which led to the development of a mechanism, governing the formation of CaCO3.

Mesoporous Carbons Produced from Tannin Biomass for Lithium-Sulfur Batteries

Lithium-sulfur batteries (LSBs) are promising alternatives since sulfur can provide a theoretical specific capacity of 1675 mA h g-1 when combined with lithium [1]. Thus, LSBs can achieve a theoretical energy density (2500 W h kg-1) that is much greater than that of conventional lithium-ion batteries [1]. However, several problems must be resolved to enable commercial production on a large scale, such as the formation of soluble species of lithium polysulfides [2]. Various approaches have been used to minimize this problem, including the development of carbon-based hosts capable of retaining these polysulfides. Among these, the development of cathodes based on carbon‒sulfur composites using carbon from biomass is an alternative that benefits from the possibility of obtaining materials with a modifiable surface area and porosity at low cost [2]. On this basis, this work reports the synthesis of mesoporous carbons (MCs) from tannin biomass, the incorporation of sulfur and the development of lithium-sulfur batteries. The MC sample was produced using the solvent-free method [3] and was named C. The incorporation of sulfur into mesoporous carbons was carried out using melt diffusion methodology [4]. Two quantities of sulfur were added to the carbon host by mass, and the materials were named CS1 and CS2 at ratios of 1:1 and 2:1, respectively, in relation to sulfur:MC. Coin cells (CR 2032) were assembled using the produced materials on the cathode, metallic Li on the anode and the electrolyte 1 M LiTFSI and 1% (w/v) LiNO3 in 1,2-dimethoxyethane/1,3-dioxolane (DME/DOL) and characterized by cyclic voltammetry (CV) and galvanostatic charge/discharge (GCD) cycling. The mesoporous carbon C presented a type IV isotherm characteristic of mesoporous materials, with a BET surface area of 539 m2g-1, average pore size of 7.7 nm and total pore volume of 0.747 cm3g-1. There was a decrease in the area and pore volume of the materials after sulfur incorporation, reaching 70 m2g-1 and 0.195 cm3g-1 for CS1 and 3 m2g-1 and 0.012 cm3g-1 for CS2, respectively. The sulfur contents were determined by thermogravimetric analysis (TGA) and were 39% and 61% for CS1 and CS2, respectively. The sulfur contents determined by TGA were close to those obtained by elemental analysis (CHNS), which were 45% and 63% for CS1 and CS2, respectively. The CV data showed that both cells presented cathodic and anodic potentials typical of Li-S batteries. The GCD data show that the cell containing the cathode with the material with a higher elemental sulfur content (CS 2) is stable and maintains specific capacities on the order of 550 mA h g-1 after 45 galvanostatic cycles at different current densities. However, this cell showed a more abrupt decrease in capacity at the highest rates (2C and 4C), Figure 1. Most likely, the higher sulfur content used in this sample did not result in total impregnation of the porous structure, resulting in sulfur deposition on the surface of the particles. As a result, the interparticle contact resistance in the electrodes increases, which limits the performance at higher current demands. For the cell built with the sample containing 39% S (CS1), excellent performance is obtained at high C rates. At 0.1 C, the cathode operates above 900 mA h g-1 in the initial cycles and above 550 mA h g-1 at 0.5 C, and no significant capacity drop is observed between 1 C and 2 C (≈500 mA h g-1). At 4C, a decrease in the specific capacity is noted, but the specific capacity remains above 350 mA h g-1. These results demonstrate the potential of carbon materials obtained from biomass for building high-performance Li-S batteries.Acknowledgments: The authors thank the financial support from the Rota 2030 Program at Fundep – Brazil.

(Invited) Low Temperature Plasma Synthesis and Functionalisation of Carbon Nanostructures for Energy Conversion and Storage

Low-temperature plasmas are nowadays widely developed and used for synthesis and functionalization of various materials with applications in areas ranging from microelectronics and aeronautical industry to energy conversion and storage. The focus of the research and applications has lately shifted towards carbon and carbon-based materials synthesis. The materials of interest vary from nanoparticles, nanotubes, nanowalls, free standing graphene flakes, vertical graphene rods, sponge structures, nanostructured surfaces, to composites (with conductive or non-conductive polymers, or MoS2, to mention some of the examples that will be presented herein). The interest for direct applications of plasma processes as well as nanostructures in the field of energy conversion and storage has been present since a long time. Recently, however, several interesting fundamental breakthroughs have been observed in terms of better control of processes, diagnostics and several other benefits that are attracting more and more attention: lower temperatures of surfaces needed for synthesis and functionalization (due to active plasma species interacting with surfaces), dry processes (diluted precurors or liquid monomers introduced in processes, without use of solvents), decreased overall pollution, fast processes, to mention just some of the advantages. However, our work must not forget the disadvantages and problems that can occur during application tests, such as stability, adhesion, loss of conductivity, reproducibility, general ageing or recyclability.Different factors can affect the function of the final setup (from photocatalytic elements, to batteries or fuel cells/HER systems, in our case) – from production of the starting materials to the assembly. Therefore, careful synthesis and control of the process (including the chamber and surface conditions for example) is necessary. We present herein several examples of carbon materials developed or in development (as mentioned 1D-3D carbons, carbon in organic and inorganic composits, mesoporous carbons). These materials were synthesized at surface temperatures between room temperature and up to 550°C.We emphasize, for example, the importance of in-situ control of processes, the importance of precise process conditions, the control of the synthesized materials with regard to their electrical conductivity, adhesion, thermal stability or sensitivity to photon irradiation.Acknowledgments:Authors acknowledge the EU Graphene Flagship FLAG-ERA III JTC 2021 project VEGA (PR-11938) and the project PEGASUS (funded by the European Union's Horizon research and innovation programme under grant agreement No 766894. UC and NMS acknowledge the Slovenian Research Agency for the program ARRS No. P1-0417 and project Z2-4467. TS, EK and JB want to thank HZB for the allocation of synchrotron radiation beamtime at the HE-SGM beamline of BESSY II. Thanks goes also to Prof. Wöll from KIT for providing the HE-SGM endstation used for the XPS and NEXAFS measurements. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 730872 (Nr. 18207084-ST and 18207393- ST). EK and JB acknowledge also support obtained via ARD MATEX Region Centre.

Synthesis Method Comparison of N-Doped Carbons for Electrochemical Energy Storage

This study investigates nitrogen-doped carbon synthesis and electrochemical properties as electrode material for energy storage devices, an additional focus of the work is on the electrochemical exfoliation synthesis of nitrogen-doped carbon using various precursors and doping methods. The physical properties of the synthesized sample are characterized using X-ray photoelectron spectroscopy, scanning electron microscopy, and Raman spectroscopy. The electrochemical properties of the N-doped carbons are studied using cyclic voltammetry and galvanostatic charge-discharge cycling. Finally, the work explores the potential application of the N-doped carbons as electrode material for energy storage devices, such as supercapacitors. The results show that N-doped carbons exhibit electrochemical performance superior to that of graphene oxide, with higher electrical capacitance. The results demonstrate the potential of N-doped carbons as high-performance electrode materials for electrochemical energy storage applications. This paper aims to explain the advantages of N-doping in carbon materials more precisely in graphene and the use of these materials in creating electrodes for application in supercapacitors and batteries.

Binary and Halide-free Catalyst Systems Based on Al/Ga/In Aminopyridylbisphenolate Complexes for the Cycloaddition of Epoxides and CO2.

Group 13 complexes bearing an aminopyridylbisphenol ligand have been prepared [ML-X; L = ligand, M = Al (X = Cl and Br), Ga (X = Cl, Br, and I), or In (X = Cl)]. The structures of the complexes containing the chloride ligand (ML-Cl; M = Al, Ga, and In) have been directly compared through an X-ray crystallography study, with differences in the monomeric or dimeric nature of their structures observed. All of the complexes obtained have been studied as potential catalysts for the synthesis of cyclic carbonates from epoxides and CO2. It has been found that the indium complex, as part of a traditional binary catalyst system (catalyst + tetra-butylammonium halide cocatalyst), displays the highest catalytic activity and is active under rather mild reaction conditions (balloon pressure of CO2). Meanwhile, it has been found that the GaL-I complex is a competent single-component catalyst (no need for addition of a cocatalyst) at more elevated reaction temperatures and pressures. A full substrate scope has been performed with both developed catalyst systems to demonstrate their applicability. In addition to the experimental results, a density functional theory study was performed on both catalyst systems. These results explain both why the indium catalyst is the most active under binary catalyst system conditions and how the gallium catalyst with an iodide (GaL-I) is able to act as a single-component catalyst in contrast to the indium-based complex.

Sustainable synthesis of N-doped carbon to stabilize Ru species for CO2 hydrogenation to formic acid

In this study, we developed nitrogen-doped carbon supporting materials from biomass-derived fertilizers, offering a sustainable and eco-friendly approach to heterogeneous catalysis for CO2 hydrogenation. Three types of fertilizers (AA50, AA80, and FV), derived from different biomass sources, were evaluated there potential to prepare the N-doped carbon structure. The synthesis of fertilizer-based supporting materials resulted in an abundant amount and a specific structure of doped nitrogen, essential for immobilizing atomically dispersed Ru catalysts during CO2 hydrogenation. The catalytic performance of the Ru catalysts supported on optimized fertilizer-derived materials exhibited a turnover number of 2748 over two hours and maintaining 98 % stability across five recycling tests. Analysis of spent catalysts showed that our fertilizer-based supports effectively prevented the sintering and leaching of the Ru catalysts. Moreover, the capability for industrial application was validated through a continuous flow reactor test, achieving an average formate productivity of 697 mmol•gcat−1h−1 over 100 hours. These results highlight the synthesized Ru catalyst on fertilizer-derived carbon material as a promising solution for eco-friendly CO2 hydrogenation to formic acid.

Highly efficient preparation of crystalline yttrium carbonate in sodium carbonate system: Formation and growth mechanism

The recovery of rare earths from industrial rare earth leaching solution is typically achieved through the ammonium carbonate precipitation method, which presents challenges in terms of prolonged production cycle and ammonia nitrogen pollution. The present study explored the synthesis of crystalline yttrium carbonate in a sodium carbonate system, employing a conventional mother liquor derived from yttrium chloride. The growth of yttrium carbonate was explored through the lens of density functional theory (DFT) calculations, unveiling a novel perspective on its formation mechanism. The synthesized yttrium carbonate demonstrates enhanced crystallinity, with a D50 value of 19.75 μm achieved under reaction conditions comprising a temperature of 60 °C, stirring rate of 200 r/min, feeding rate of 4 mL/min, and aging time of 30 h. The molar ratio for precipitation is set at 1.6:1. The morphology of yttrium carbonate undergoes a transition from needle-like structures to sheet-like formations, ultimately culminating in the formation of spherical aggregates. The variation in surface energy among distinct crystal planes and CO32– configurations within crystal cells accounts for this phenomenon. The DFT calculations unveil a progression of growth and transformation in yttrium carbonate, commencing from a one-dimensional configuration and culminating in a multidimensional morphology.

Synthesis of Carbon–Carbon Composites Based on Anthracite of the Gorlovskii Basin

Synthesis of Carbon–Carbon Composites Based on Anthracite of the Gorlovskii Basin

Leveraging porosity and morphology in hierarchically porous carbon microtubes for CO2 capture and separation from humid flue gases

Leveraging porosity, surface chemistry and morphology of porous carbons play a critical role in CO2 capture performance. However, the effective and sustainable synthesis of porous carbons with well-interconnected hierarchical pore structure, high-proportioned micropores and high yield remains a huge challenging by a mild one-step chemical activation without damaging the natural unique nanostructure. Here, we proposed a green and sustainable strategy to fabricate porous carbons with tailorable porosity and unique tubular structure by an inorganic dynamic porogen of CuCl2. The dynamic activation mechanism of CuCl2 was explored in detail. In particular, the hierarchical porosity with a high-proportioned narrow micropores can be finely tuned without sacrificing the natural tubular morphology. Importantly, the resultant porous carbon adsorbents have an excellent resistance to water vapor, which can capture CO2 from humid flue gases with satisfactory adsorption capacity and selectivity. The HPCM-3 can achieve the best CO2 uptakes of 4.05 and 2.05 mmol/g under 100 kPa at 25 and 50 °C, respectively. Such superior CO2 adsorption behaviors can be well maintained even at high humidity of 70 %, and hardly decay with the enhancement of humidity. This route provides a promising avenue for developing the practical trace CO2 carbon-based adsorbents on a large scale to sieve CO2 from humid flue gases.

Novel synthesis of thermoresponsive single-walled carbon nanotubes/poly(N-isopropylacrylamide) hybrids

Poly(N-isopropylacrylamide) (PNIPAM) is one of the most well studied thermoresponsive polymers and its microgels undergo a reversible volume phase transition (VPT) at temperatures close to that of the human body. Coupling this property with the unique optical properties of single-walled carbon nanotubes (SWCNT) in the near infrared (NIR) leads to interesting nanohybrids that could be used as multi-responsive sensors/actuators for biological applications.We show the synthesis of thermoresponsive SWCNT/PNIPAM hybrids using two different non-covalent strategies, preserving the nanotube optical properties such as fluorescence. The first strategy involves the dispersion of the SWCNT in water with sodium dodecyl sulfate (SDS), and subsequent in situ synthesis of PNIPAM microgels inside the SDS coatings around the nanotubes. The second strategy starts with modifying the nanotubes with a pyrene derivative, which in turn is used as the starting point for the in situ polymerization of the PNIPAM microgels, thus ensuring that the polymer grows around the nanotubes. In both cases, we obtain hybrids showing a phase transition at temperatures close to that of the human body, with the absorption and fluorescence spectra of the hybrids in the NIR changing in response to the changing dielectric environment. These systems could be used as actuators/sensors in biological systems.

Potential Development of Porous Carbon Composites Generated from the Biomass for Energy Storage Applications.

Creating an innovative and environmentally friendly energy storage system is of vital importance due to the growing number of environmental problems and the fast exhaustion of fossil fuels. Energy storage using porous carbon composites generated from biomass has attracted a lot of attention in the research community. This is primarily due to the environmentally friendly nature, abundant availability in nature, accessibility, affordability, and long-term viability of macro/meso/microporous carbon sourced from a variety of biological materials. Extensive information on the design and the building of an energy storage device that uses supercapacitors was a part of this research. This study examines both porous carbon electrodes (ranging from 44 to 1050 F/g) and biomasses with a large surface area (between 215 and 3532 m2/g). Supposedly, these electrodes have a capacitive retention performance of about 99.7 percent after 1000 cycles. The energy density of symmetric supercapacitors is also considered, with values between 5.1 and 138.4 Wh/kg. In this review, we look at the basic structures of biomass and how they affect porous carbon synthesis. It also discusses the effects of different structured porous carbon materials on electrochemical performance and analyzes them. In recent developments, significant steps have been made across various fields including fuel cells, carbon capture, and the utilization of biomass-derived carbonaceous nanoparticles. Notably, our study delves into the innovative energy conversion and storage potentials inherent in these materials. This comprehensive investigation seeks to lay the foundation for forthcoming energy storage research endeavors by delineating the current advancements and anticipating potential challenges in fabricating porous carbon composites sourced from biomass.

Controllable synthesis of carbon supported cobalt monoxide anode and high-voltage lithium cobalt oxide cathode with enhanced lithium-ion storage

Natural macromolecule amylose (AM) is employed to deoxygenate few-layered graphene oxide (GO) and modulate the surface interaction between GO sheets and Co2+ ions under mild hydrothermal conditions. The obtained Co2+ ions and AM molecule jointly decorated reduced graphene oxide (Co-AM/RGO) sample is further utilized to synthesize both anode and cathode materials with controlled microstructures. To synthesize anode material, the Co-AM/RGO can be directly converted to a hierarchical AM pyrolyzed carbon and RGO supported cobalt monoxide nanocomposite (CoO@AMC/RGO) after a simple inert gas protected thermal treatment. To synthesize cathode material, a carbon coated nano-sized lithium cobalt oxide sample (LiCoO2/C, LCO/C) can be obtained after a solid-state reaction in air by mixing lithium salt with the Co-AM/RGO. The CoO and LCO nanocrystals with significantly controlled sizes are well dispersed in the carbon matrices. The CoO@AMC/RGO anode shows a high reversible capacity of 785.25 mAh·g−1 after 500 cycles at 200 mA·g−1 and 608.25 mAh·g−1 after 700 cycles at 1000 mA·g−1, while the LCO/C cathode delivers a superior reversible capacity of 140.91 mAh·g−1 after 1000 cycles at 1000 mA·g−1 with a high cut-off voltage of 4.6 V. This work provides a new perspective for controllable engineering of electrode materials with enhanced lithium-ion storage performances.

Bottom-up fabrication of DABCO-based bicationic ionic liquid-grafted MIL-101(Cr): Facilitating simultaneous activation of CO2 and epoxides for cyclic carbonate synthesis

Efficient activation of substrates as an orthogonal pathway for facilitating CO2 fixation into cyclic carbonates, poses ongoing challenges for the ingenious design and development of heterogeneous cooperative catalysts. Herein, a bottom-up strategy was employed to stepwise graft chloromethyl, triethylenediamine (DABCO), and chloroethylamine onto the organic linkers, forming bicationic ionic liquid tethered to MIL-101(Cr). The introduced –NH2 and quaternary ammonium groups dangling within the micro-mesopores ensured the fast enrichment and polarization of CO2 molecules, while the inherent unsaturated Cr3+ sites bonded with the epoxides to promote the simultaneous activation. The ample Cl- counter-anions further nucleophilically attacked to proceed the ring opening process, triggering an upgradation in catalytic performance for cycloaddition. After optimized by the response surface methodology (RSM), a chloropropene carbonate (CPC) yield of 97.8 % with a selectivity of 99.3 % were attained over the developed Cl[TNH2]Cl@MIL-101(Cr) at mild conditions (104.5 °C, 1.07 MPa, 3.75 wt% of catalyst, 1.91 h) in the absence of any solvent or co-catalyst. Furthermore, Cl[TNH2]Cl@MIL-101(Cr) displayed good durability, universality, and recyclability. The synergy of multiple sites was testified by the in-situ DRIFTS spectra and DFT calculations, and thus the potential catalytic mechanism was deduced. The implement of this work could shed some lights on the rational assembling of robust IL@MOFs nanocomposites and offered novel avenues for the fabrication of high-efficiency catalysts for practical CO2 conversion.

Biomimetic Synthesis of Calcium Carbonate in Bile in the presence of Amino Acids

Thermodynamic and experimental modeling of calcium carbonate crystallization in a model solution of human bile has been carried out. The process of calcium carbonate (calcite and vaterite) crystallization from solutions containing bile has been studied. It is shown that differences in the phase and group composition of the samples arise depending on the synthesis parameters. It has been established that in the presence of 1 wt. % bile, calcite is formed, and an increase in the concentration of bile in the initial solution from 5 to 100 wt. % contributes to the crystallization of vaterite. It is shown that the mass of the solid phase increases with an increase in the concentration of bile in the initial solution. The dissolution of the synthesized samples was performed in 0.9 wt. % NaCl solution and 0.05 M EDTA solution. It was found that the presence of bile components in the composition of solid samples reduces the rate of their dissolutions.

Heterogeneous carbon coated resin-based hard carbon anode material for high-performance sodium ion batteries

Resin-based hard carbons are promising anode materials for sodium ion batteries (SIBs) due to their high storage capacity and purity. However, the low initial coulombic efficiency (ICE) still hinders their practical application. Crosslinking and high-temperature pyrolysis strategies have been demonstrated to improve ICE effectively, but the complex process and high energy consumption hinder their industrialization. This paper proposes a facile synthesis of resin-based hard carbon with a soft carbon coating strategy to improve ICE. By carbonizing commercial phenolic resin at 1150℃, hard carbon with a reversible capacity of 291.6 mAh g−1 and 82.6 % ICE was obtained. After asphalt-based soft carbon coating, the optimized sample (CHC-1150) with a heterogeneous carbon coating layer of about 8.5 nm displays a high reversible capacity and ICE of 309.8 mAh g−1 and 88.2 %. Moreover, when combined with NaFe1/3Ni1/3Mn1/3O2 cathode, the assembled 18650 cylindrical-type batteries deliver a high ICE of 84.3 %, excellent low-temperature capability and cycling stability. Additionally, the disassembly results after cycling indicate that the soft carbon layer can inhibit the decomposition of electrolytes and avoid sodium plating. These encouraging results suggest that heterogeneous carbon coating should be a promising strategy to promote the electrochemical performance of resin-based hard carbon anode materials for SIBs.

Mn-doped CeO2 derived from Ce-MOF porous nanoribbons as highly active catalysts for the synthesis of dimethyl carbonate from CO2 and methanol.

It is desirable but challenging to develop highly-efficient catalysts for the direct synthesis of dimethyl carbonate (DMC) from methanol and CO2. The vacancy-mediated incorporation of heteroatom into surface reconstruction is an efficient method of defect engineering for enhancing the catalytic properties. In this work, manganese-doped cerium oxide porous nanoribbons (Mn/CeO2-BTC) were prepared derived from a Ce-BTC by a sacrificial template approach. It is found that the catalytic activity of Mn/CeO2-BTC catalysts can be readily controlled by varying the amount of Mn dopants and the as-synthesized 0.1-Mn/CeO2-BTC exhibited an outstanding activity for the synthesis of DMC from CO2 and methanol, which reached a high DMC yield (6.53 mmolDMC/gcat.) without any dehydrating agents. Based on characterization results, the enhanced performance may be attributed to the defective structures caused by Mn doping and the porous nanoribbons of the CeO2 crystals, which provide more surface oxygen vacancies and acidic-basic sites, favoring adsorption and activation of CO2 and methanol.

Synthesis of a green functional carbon dioxide‐based polycarbonate using bio‐based monomers

AbstractA PPC‐dodecyl glucoside (PPC‐APG) polymer was synthesized by the terpolymerization of carbon dioxide (CO2), propylene oxide (PO), and the bio‐based monomer APG for the first time. The thermal stability and mechanical properties of PPC‐APG were significantly improved compared with those of conventional polypropylene carbonate (PPC), and its glass transition temperature (Tg) was increased by 14°C compared with that of PPC. The 5% heat loss temperature (Td,−5%) and total heat loss temperature (Td,max) of PPC‐APG were increased by 89.1 and 92.1°C, respectively, compared with those of PPC. The tensile strength of PPC‐APG was increased to 25.6 MPa, its elongation at break was decreased to 125.1%, and its thermal elongation and permanent deformation were reduced to 97.2% and 62.9%, respectively, which improved the processability of the material. In addition, the introduction of bio‐based monomers also rendered PPC‐APG functional, and its surface tension reached a maximum of 61.3 mN/m at a concentration of 0.05 g/mL, with a good degradability. The higher surface tension and enhanced degradability of PPC‐APG indicate its potential for application as a plastic printing substrate.

High efficiency azo dye removal via a combination of adsorption and photocatalytic processes using heterojunction Titanium dioxide nanoparticles on hierarchical porous carbon

Amidst the rapid development of the textile industry, wastewater problems also arise. High-performance materials for reactive black 5 (RB5) dye treatment by adsorption and photocatalysis were evolved using Titanium dioxide (TiO2) nanoparticles on carbon media. Herein, the synthesis of spherical carbon via the water–in–oil emulsion method alongside a sol–gel process and the production of TiO2 nanoparticles using the precipitation procedure of Titanium isopropoxide and carbonization at 700–900 °C for 2 h are a novel approach in this work. The characterization of these materials indicates that different temperatures result in distinct properties, for instance, raised pores on the surface of the media and changes in the crystal structure of TiO2. The results show that the as-synthesized material carbonized at 900 °C had distinguished dye adsorption, up to 430 ppm in 1 h, due to their high surface area and pore volume. On the contrary, the calcined 700 °C condition had the prominent photocatalytic efficiency on account of the heterojunction band gap between anatase and rutile crystal structure. A mixed phase minimizes the charge recombination, subsequently increasing the photocatalytic capability.