Journal of Porous Materials最新文献

This study addresses the prevalent use of chemically synthesized carbon nanomaterials in commercial supercapacitors, accounting for over 80% of deployments, marked by costliness and reliance on non-renewable resources. In response, biowaste is explored as a prospective source of sustainable carbon. The research focuses on converting biomass waste into an economically viable, high-performance electrical energy storage system. Renewable and environmentally benign biomass feedstock is prioritized for cost-effective and sustainable supercapacitor electrode design. A cost-effective three-dimensional (3D) porous honeycomb carbon is synthesized from bamboo shells via carbonization and activation with potassium hydroxide (KOH). The resulting activated carbon exhibits significant porosity and a high specific surface area, validated by Brunauer-Emmett-Teller (BET) analysis. Morphological studies using field emission scanning electron microscopy (FESEM) showcase the 3D honeycomb structure. Structural analyses through Raman spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) further affirm the material’s characteristics. The carbonized bamboo shell-derived electrode demonstrated an outstanding specific capacitance of 310 and 135 F/g at 1 A/g in a three-electrode and two-electrode systems respectively. Remarkably, even after 10,000 cycles at a current density of 2 A/g in a 2 M KOH aqueous electrolyte solution, the electrode exhibited remarkable capacitance retention at 78%. The fabricated symmetric cell demonstrates high values of an energy density of 10.8 Wh/kg and a power density of 720 W/kg at 1 A/g. Utilizing the developed electrode, a symmetric supercapacitor device is successfully demonstrated by illuminating ten red light-emitting diodes (LEDs), showcasing its practical utility in energy storage applications.

Mono and bimetallic modified MCM-41(Mobil Composition of Matter No. 41): Zn-MCM (ZM), Zn/Co-MCM41 (ZCM), and Zn/Pd-MCM-41 (ZPM) molecular sieves were produced by a surfactant-assisted technique. The structural and textural features were examined through spectroscopic and analytical techniques. The XRD analysis indicated broadening of diffraction peaks and a shift towards higher 2-theta values in the metal-incorporated (M-MCM-41) samples, confirming the successful integration of metal atoms into the MCM-41 framework; it also highlighted the preservation of a hexagonal structure with reasonable regularity, emphasizing the influence of metal incorporation on the mesoporous architecture of MCM-41. N₂ adsorption–desorption isotherms revealed type IV isotherms for all samples; the BET specific surface area decreased to 672.48, 667.90, and 562.50 m²/g in ZM, ZCM, and ZPM, respectively comparing to the unincorporated MCM-41 sample (1200 m²/g), indicating partial filling of mesopores by metal centers, as confirmed by TEM images. The diffuse reflectance spectra exhibited a noteworthy optical band gap reduction of MCM-41 (5.98 eV) upon the incorporation of Zn and Co/Zn ions, resulting in values of 5.86 and 5.24 eV, respectively, with refractive index values close to 2. Additional absorption bands energies are observed at 3.14, 3.18, and 1.70 eV in ZM, ZPM, and ZCM samples, respectively suggesting the suitability of the metal incorporated samples for the photocatalytic applications. The M-incorporated samples exhibited a decline in the transmission intensity accompanied by small shifts. The enhanced antimicrobial activity of the metal-incorporated samples, surpassing that of the pure MCM-41 against a variety of tested microorganisms, is attributed to the presence of incorporated metal species, which create a more acidic environment and substantially contribute to the heightened antimicrobial effectiveness. The ZM compound demonstrated potent inhibition against Bacillus cereus and Pseudomonas aeruginosa bacteria, displaying comparable efficacy to Ampicillin, as a reference antibiotic. Additionally, ZPM exhibited considerable inhibitory activity against Escherichia coli, surpassing the reference antibiotic and showing similar effectiveness against Bacillus cereus, Pseudomonas aeruginosa, and Salmonella typhimurium.

NaTi₂(PO₄)₃, as one of sodium superionic conductor (NASICON)-type anode materials, has been extensively concerned by researchers in Na-storage technologies due to their unique three-dimensional structure for Na⁺ insertion/deinsertion. However, the low conductivity of NaTi₂(PO₄)₃ seriously hinders its electrochemical kinetics, which has been a major obstacle to further application. Herein, a facile strategy is proposed to synthesize carbon-incorporated NaTi₂(PO₄)₃ nanoparticles on carbon cloth (NTP/C@CC) as a binder-free anode for aqueous sodium-ion hybrid capacitors (SIHCs). The amorphous carbon as a continuous conductive network can improve the electronic conductivity and restrict the particle growth of NaTi₂(PO₄)₃. The small-sized NaTi₂(PO₄)₃ nanoparticles embedded in the carbon network could increase the electrolyte/electrode interfacial area and shorten the Na⁺ transport path, resulting in increased electrochemical performance. Meanwhile, the carbon matrix can buffer the volume expansion during cycling and stabilize the structure of active materials. Consequently, the NTP/C@CC anode possesses a high specific capacity (0.416 mAh cm^− 2 at 2 mA cm^− 2), considerable rate capability (0.172 mAh cm^− 2 at 30 mA cm^− 2, 41.3% capacitance retention), and good long-term stability (83.2% capacitance retention after 5000 cycles at 30 mA cm^− 2). In addition, an assembled SIHC device with P-doped porous carbon cloth (PPCC) as the cathode shows a capacity of 0.205 mAh cm^− 2. The SIHC cell also acquires a superior energy density of 2.82 mWh cm^− 3 and 81.5% capacity retention over 5000 cycles. This work may offer a viable way for constructing binder-free electrode materials for hybrid capacitors.

This work reports the amine and mercapto bi-functionalized mesoporous silica MCM-41 for heavy metal ions removal from aqueous solutions. XRD, FTIR and N₂ adsorption–desorption analyses confirmed that a series of bi-functionalized mesoporous silica MCM-41 with huge specific surface area were successfully obtained. In aqueous solution, the adsorption performance were evaluated by the adsorption of Zn(II), Cu(II), Cr(III) and Pb(II). The obtained results indicate that synthesis process has no significant influence on the structure and the existence of functional group resulted in outstanding adsorption capacity. The methodology of pre-hydrolysis was one effective treatment for grafting useful functional group on to mesoporous silica. The adsorption reactions for the adsorption of heavy metal ions by bi-functionalized silica-based mesoporous materials were spontaneous adsorption processes over the range of experimental temperatures. The adsorption isotherm is consistent with the Freundlich adsorption isotherms model. The Freundlich parameters K_F and n indicated favorable adsorption. The adsorption kinetics of heavy metalions over these bi-functionalized mesoporous silica could be well described by pseudo-second-order models. Therefore, this bi-functionalized mesoporous material has promise for the removal and recovery of heavy metal ions from water.

The primary aim of this study is to break down the methoxy (-OCH₃) and hydroxyl(-OH) oxygenates present in lignin, a component of biomass. This degradation was performed on a lignin-derived model compound, guaiacol, using a highly effective Ni-loaded SBA-15 catalyst. SBA-15 was synthesized via a hydrothermal method, and varying amounts of NiO (5, 10, 15, 20, 25 wt%) were incorporated into SBA-15 through wet impregnation. The catalysts were characterized by using techniques such as XRD, DRS-UV, FT-IR, TPR, BET, SEM, and HR-TEM. Their catalytic performance was evaluated through the hydrodeoxygenation of guaiacol in a vapor phase reactor under controlled atmospheric pressure conditions. Notably, at 200 °C with a hydrogen flow rate of 50 ml/h, the 10 wt% NiO/SBA-15 catalyst demonstrated superior catalytic activity, achieving high guaiacol conversion and aimed product selectivity.

As the frequency range of electronic devices gradually expands, exploring frequency insensitive electromagnetic wave adsorption (EWA) materials that can achieve effective absorption in all bands has aroused great interest. A series of Fe_1 − xS@C composite materials with three-dimensional conductive networks were successfully prepared in this work. In the preparation process, poly (aryl ether sulfone) with branched carboxylic (PAES-C) was selected as the skeleton and Fe³⁺ ions were introduced via chemical adsorption. The main purpose of this work was to develop array porous composite materials with good EWA property. The work proposed a novel controllable method for preparing metal sulfides to explore the electromagnetic wave absorption. This routine was also developed to prepare other M_xS@C composites (M = Fe, Cu, Mn). Compared to Mn_xS@C and Cu_xS@C composites, the RL_min value of Fe_1 − xS@C-4 was − 40.6 dB at 13.52 GHz, and at a thickness of 1.5 mm the effective bandwidth reached 3.12 GHz. Furthermore, its effective absorption band covered Ku, X, and C radar bands at different thicknesses.

Fischer-Tropsch synthesis (FTS) is viewed as an effective method for producing clean fuels. Catalysts with high activity and selectivity, especially the latter, are the key to improving the catalytic performance. Herein, we report the preparation of an excellent bifunctional Fe + ZSM5 catalyst by employing novel hierarchical porous Fe₂O₃ cage particles as FTS sites and porous ZSM5 as catalytic cracking sites. The selectivity for gasoline fuels (C₅-C₁₁) selectivity over the Fe + ZSM5(33) catalyst is as high as 65.1 wt%, which is greater than that of traditional outstanding than the traditionally zeolite-supported and physically mixed bifunctional catalysts. The enhanced catalytic performance can be attributed to the weak acid content governing the catalytic cracking. ZSM5 zeolite with a suitable weak acid content and desorption temperature can facilitate the cracking of C₁₂₊ hydrocarbons, thereby facilitating the C₅-C₁₁ selectivity and inhibiting the deactivation of active sites resulting from the aggregation of C₁₂₊ hydrocarbons. Fe + ZSM5(27) with an suitable weak acid content provides a higher CO conversion of 93.6% combined with an excellent C₅-C₁₁ selectivity of 62.7 wt%. This finding provides a promising strategy for designing bifunctional catalysts with controllable product distribution.

Based on sustainable resource recycling, we utilize physical and chemical activation to modify sugarcane bagasse into activated carbon materials with a porous structure. The activated carbon modified with KOH-KNO₃ exhibits a high specific surface area and excellent specific capacitance, and the fabricated composite electrode demonstrates superior electrical conductivity of 57mS/cm. Subsequently, a supercapacitor containing an electrode, gel electrolyte, and separator is assembled in a sandwich structure. It achieves a specific capacitance of 262.4 F/g, an energy density of 17.9 Wh/kg, and a power density of 2021 W/kg at a scanning rate of 0.02 V/s. Furthermore, the supercapacitor demonstrates excellent cycle stability since it can maintain 98.38% of its initial capacitance after 20,000 cycles of charge and discharge under a constant current. In addition, the KOH-KNO₃-modified activated carbon composite electrode exhibited superior electrochemical performance after we compared it to other carbon electrode supercapacitors derived from agricultural wastes.