Journal of Porous Materials最新文献

The reduction of nitrophenols is a broadly accepted model for catalytic processes. Incorporating nanostructures into porous materials is becoming more widely acknowledged for its great importance. This strategy has attracted much interest because of its exceptional features imparted on the catalysts, offering enormous promise in accelerating the reduction of nitrophenols. In recent years, various nanostructures have been embedded to a wide range of porous materials, such as carbon, silica, metal-organic frameworks, and other inorganic materials. These porous frameworks possess unique physical and chemical characteristics, making them well-suited for catalytic applications. This thorough review begins by explaining the mechanism of nitrophenol reduction, exploring several nanostructures based on noble metals that are commonly used for catalytic reduction. Following that, a systematic description and comparison of nitrophenols catalytic reduction using various nanostructures on porous templates such as carbon-based, silica-based, zeolite-based, polymer-based, and metal-organic frameworks (MOF) were explained. In addition, this paper also examines several functional materials to enhance the catalytic reduction of nitrophenols. Herein, this write-up intends to narrow the knowledge gap on the recently synthesized catalysts and the practical requirements for removing nitrophenol. This write-up is hoped to offer valuable insights that can aid in the practical utilization of these catalysts for wastewater remediation applications.

A silica-enhanced agarose monolith adsorbent was synthesized and evaluated as a highly porous and robust adsorbent for the removal of Janus Green B (JGB) as a cationic dye from aqueous solutions. For this purpose, the molded agarose monolith adsorbent was reinforced by incorporating silica into its structure. The effects of sample volume, pH, contact time, and stirring speed on the removal efficiency of the sorbent were optimized using a response surface methodology with a central composite design. Under the optimal conditions, the monolith achieved satisfactory removal efficiencies greater than 98% for JGB. The maximum adsorption capacity of the agarose-silica adsorbent for 200 mg L^− 1 of JGB was approximately 60 mg g^− 1. Structural and morphological characterization was performed using Fourier transform infrared spectroscopy, scanning electronic microscopy and, energy-dispersive X-ray spectroscopy. The monolith exhibited excellent regenerable properties, with a removal efficiency exceeding 96% after three times of usages. Equilibrium adsorption data showed better agreement with the Freundlich isotherm model compared to Langmuir. This work demonstrated the enhanced physical stability and high porosity of the agarose-silica monoliths for the efficient removal of JGB cationic dye from real-life water and wastewater samples.

Expanded Graphite (EG) has been widely used for treating oil-polluted water. Removal of dye pigments from oily wastewater is the biggest challenge for paint industries. So, the present work focuses on treating simultaneously oil and dye-contaminated water by introducing TiO₂/EG composite. EG samples with the highest exfoliation volume have been prepared by microwave irradiation by optimizing time and tested through an oil adsorption study with different oils. TiO₂ NPs have been synthesized by the sol–gel method. A novel EG/TiO₂ composite has been synthesized by mixing TiO₂ NPs in graphite intercalation compound (precursor) and exfoliating the mixture for the optimized irradiation time. A comparative study of the effect of EG, TiO₂ NPs, and EG3/TiO₂ composite on oil and dye-polluted water has been performed in direct sunlight. Results of UV–visible spectroscopy showed that the addition of TiO₂ NPs with EG accomplished the dye degradation along with the adsorption of oil from polluted water.

Activated carbon with appreciable level of porosity and honeycomb like structure was synthesized through simple KOH activation of biochar obtained from Caladium tricolor leaves. The synthesized activated carbon was characterized for morphological and structural characteristics using various techniques. The material possesses an enhanced BET surface area (S_BET) of 1429m²/g with significant microporous texture. XPS data revealed the presence of Nitrogen as the inherent dopant in the material which enhance electrochemical and adsorption perfmance. The activated carbon has been employed as electrode material for electrical double layer type capacitance (EDLC) type supercapacitor which showed promising specific capacitance of 428 F/g at a current density of 1 A/g. Cyclic stability studies revealed a retention of capacitance of 98% for 5000 cycles. Further, adsorption studies were conducted using Furazolidone drug and the adsorption efficiency was found to be 90% following Langmuir isotherm model. Kinetic studies revealed that the adsorption follows pseudo-second order kinetics. The material also investigated for ORR activity which showed notable results which can be further improved to be employed as a metal free Oxygen reduction reaction (ORR) catalyst.

This study was performed to achieve two important scientifically challenging goals, environmental remediation of toxic heavy metals and utilization of agricultural lignocellulosic wastes. In this work, a series of mesoporous magnetic carbon (MMC) adsorbents were synthesized by carbothermic reduction at different temperatures employing date palm (Phoenix dactylifera L.) stones as the carbon source. The synthesized adsorbents were characterized by different technquies and the results confirmed the presence of zero-valent iron (ZVI) nanoparticles and other iron oxides as products of the carbothermal reduction. The nature of phases present, crystallite size and the surface properties were found to be dependent on the calcination temperature. The adsorbent MMC700 exhibited the smallest (ZVI) crystallite size 36 nm and the largest S_BET 341 m²/g. All adsorbents showed mesoporous structure with mesopore average diameter lower than 6 nm. The performance was evaluated in the removal process of toxic Cr(VI) in an aqueous medium, and the optimum conditions of the process were reported. The removal process was dependant of solution pH where best results was achieved at pH = 2. Complete removal of chromium was achieved in less than 5 min by MMC700. The results were better fitted with pseudo-second-order kinetics and followed the Freundlich model isotherm. The maximum adsorption capacity was found to be 265.25 mg/g for MMC700, suggesting its application as an efficient, low-cost, and easily separable adsorbent for the toxic Cr(VI) removal process. The prepared adsorbents exhibited superior performance in the removal process compared to other agricultural wastes or biomass - derived adsorbents reported in literature.

Nanosized ZSM-5 zeolite with high-quality is highly desired in industrial application. This paper reports an approach of rapid synthesis of this type zeolite, being realized by crystallizing gels with the Si/Al atomic ratio of 12.5–80 at 170 ℃ for 12 h under assistance of guanidinoacetic acid (GAA). As a result, the zeolite obtained from the synthesis possesses little crystal size (120–220 nm), high-quality and good monodispersity. Being associated with the superior morphology and structure, the zeolite displayed not only longer one-pass catalytic lifetime but also much higher regeneration stability in methanol-to-olefin reaction, comparing with the zeolite synthesized without GAA addition.

A multifunctional catalyst with attractive recuperation was manufactured by impregnating 4-dimethylamino pyridine (MP) with Ni supported on MCM-41 coated with CoFe₂O₄ (MCM-41/CoFe₂O₄/MP/Ni), which effectively acted as a selective catalyst for the synthesis of tetrazole and selective oxidation of sulfide with high effectiveness. The structures of the hybrid were examined by high-resolution transmission electron microscopies (TEM), field emission scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDS), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), vibrating-sample magnetometer (VSM), elemental mapping, and nitrogen adsorption−desorption isotherm. The hexagonal system of MCM-41 is well preserved after CoFe₂O₄ and 4-dimethylamino pyridine/Ni embedding. Results showed that the magnetite nanoparticles were coated with the MCM-41 silica with the formation of core–shell structured materials, and the 4-dimethylamino pyridine (MP) was successfully immobilized on the core–shell structured support. In this approach, the MCM-41/CoFe₂O₄/MP/Ni composite with spherical particles consisted of a mesoporous structure. This catalyst was recovered and reused several times without significantly decreasing efficiency and stability.

Although photothermal materials (PMs) are widely utilized in pure water and seawater, there is less research on the design and preparation of multifunctional photothermal materials with organic dye adsorption and oil displacement properties. In this study, biomass carbon aerogel (BC) was prepared through a simple Ca²⁺ cross-linking and freeze-drying process. To enhance the antifouling performance of BC, hydrophilic and oleophobic chemical modification was conducted to obtain BC-SP. The contact angle of n-hexadecane can reach to 141.8°, which enable the extensive application of BC-SP in oil-bearing wastewater treatment. Notably, BC-SP exhibited exceptional light absorption efficiency (approximately 95%), excellent heat insulation performance (thermal conductivity 0.0650 W m^− 1 K^− 1), and rapid water transport capability. Under the irradiation of 1 kW m^− 2, the solar energy conversion efficiency can reach to 86.8%. After tested eight cycles, the evaporation efficiency remained relatively stable and can adsorb most organic dyes in dye wastewater. Therefore, the study of BC-SP in this paper may has broad practical application prospects.

A series of Co-Mo sulfide catalysts with tube-like hollow structure were prepared by a low temperature pre-sulfurization method using various CoMoO₄ as precursors synthesized by coprecipitation process at different temperature. The crystallite structure of CoMoO₄ precursors determined the properties of Co-Mo sulfide catalysts, including pore structure, concentration of CoMoS active phase, microstructure of MoS₂ slabs, and desulfurization activity. The higher temperature led to better crystallinity of CoMoO₄ precursor, resulting in less CoMoS active phase and fewer Mo atoms at the corner sites of the pre-sulfurized catalyst. In addition, the MoS₂ slabs with shorter length and more stacking layers (especially Co-promoted MoS₂ slabs) in the catalysts are also formed at appropriate precursor preparation temperature, which are favorable for forming more unsaturated coordination sites (especially corner sites). According to the results of hydrodesulfurization of dibenzothiophene on the Co-Mo sulfide catalysts, the reaction rate and the production yield are highly dependent on the number of surface-active centers, while the activity is mainly attributed to the Type II CoMoS species.

Thermally induced phase separation (TIPS) allows preparation of nano and micro-porous structured materials for various applications. The literature thoroughly examines the impact of initial polymer solution concentration and cooling rate on the products morphology. On the contrary, the influence of the solvent removal methods was so far researched scarcely. Hence, we compare both qualitatively and quantitatively the effects of the solvent removal method on pore size distribution, structure, porosity, and thermal conductivity. Our study was carried out with samples prepared by TIPS from polystyrene/cyclohexane solutions employing either extraction agent or lyophilization at different solvent removal temperatures. Materials exhibited interconnected pore structure, implying good sound insulation properties, and had low thermal conductivity, offering the combination of thermal and sound insulation in one layer of material. Pore sizes after lyophilization were up to two times larger than after solvent removal by an extraction agent. On the other hand, the use of extraction agent led up to 10% porosity decrease with average porosity after lyophilization being above 82%. Our findings demonstrate that the solvent removal method is an important parameter during TIPS and that pros and cons of both methods should be carefully considered to obtain optimal material and TIPS process economy.