Resorcinol Formaldehyde Research Articles

Hierarchical porous carbon guided by constructing organic-inorganic interpenetrating polymer networks to facilitate performance of zinc hybrid supercapacitors

Customized design of well-defined cathode structures with abundant adsorption sites and rapid diffusion dynamics, holds great promise in filling capacity gap of carbonaceous cathodes towards high-performance Zn-ion hybrid supercapacitors (ZHC). Herein, we fabricate a series of dynamics-oriented hierarchical porous carbons derived from the unique organic-inorganic interpenetrating polymer networks. The interpenetrating polymer networks are obtained through physically knitting polyferric chloride (PFC) network into the highly crosslinked resorcinol-formaldehyde (RF) network. Instead of covalent bonding, physical interpenetrating force in such RF-PFC networks efficiently relieves the RF skeleton shrinkage upon pyrolysis. Meanwhile, the in-situ PFC network sacrifices as a structure-directing agent to suppress the macrophase separation, and correspondingly 3D hierarchical porous structure with plentiful ion-diffusion channels (pore volume of 1.35 cm3/g) is generated in the representative HPC4via nanospace occupation and swelling effect. Further removal of Fe fillers leaves behind a large accessible specific surface area of 1550 m2/g for enhanced Zn-ion adsorption. When used as the cathode for ZHC, HPC4 demonstrates a remarkable electrochemical performance with a specific capacity of 215.1 mAh/g at 0.5 A/g and a high Zn2+ ion diffusion coefficient of 11.1 × 10−18 cm2/s. The ZHC device yields 117.0 Wh/kg energy output at a power density of 272.1 W/kg, coupled with good cycle lifespan (100,000 cycles@10 A/g). This work inspires innovative insights to accelerate Zn diffusion dynamics by structure elaboration towards high-capacity cathode materials.

Producing Hardwood Cross-Laminated Timber (HCLT) Mats from Low-Grade Red Oak Lumber

Abstract The use of cross-laminated timber (CLT) has significantly grown in North America, but hardwood species have not yet been deemed a viable raw material for manufacturing CLT panels. Therefore, softwood species continue to serve as the only approved material for CLT in structural applications according to ANSI/APA PRG-320. Nonstructural CLT products that utilize low-grade lumber from hardwood species, are a good option for introducing hardwoods into the CLT market. Of the hardwood species located within Appalachia, northern red oak (Quercus rubra) is readily available. The purpose of this research was to develop hardwood cross-laminated timber mats utilizing low-grade red oak lumber. In order to manufacture red oak CLT mats, the best adhesive and bonding parameters had to be identified. Overall, sample CLT panels were made using three adhesives with nine different setups for each adhesive. The sample panels were processed into smaller blocks and separated for cyclic delamination and shear-block tests following the ANSI/APA PRG-320 standards. This research determined that a phenol–resorcinol formaldehyde (PRF) adhesive produced the lowest percentage of delamination, satisfying the delamination requirements. The PRF adhesive also produced the largest percentage of wood failure in shear-block testing, however, the results fell short of meeting the requirements. A Taguchi statistical analysis was used to predict the optimal bonding parameters for each adhesive. The optimized bonding parameters for the polyurethane (PUR) adhesive produced favorable results, indicating the delamination results have the potential to nearly meet the standard requirements, while the predicted shear results would exceed the requirements.

Enhancement of mechanical and thermal properties of carbon fiber phenolic resin composites using silicon carbide filler for thermal protection system applications

Thermal protection systems (TPS) are vital for re-entry vehicles for their safe passage into the atmosphere from space. Hence, researchers took a keen interest in improving the thermal and ablative properties of composites to be used in making thermal protection systems. Therefore, an attempt was made to improve the thermal and ablative properties of composites made of carbon fibers (Cf) and resorcinol formaldehyde phenolic (Ph) resin with the incorporation of silicon carbide (SiC) particles. The filler was added in various percentages (0 wt% - blank, 1 wt%, 3 wt%, and 5 wt%), and the composites were tested for ablative, thermal and mechanical properties. The results demonstrate that the SiC-modified PAN-based carbon fiber reinforced phenolic (SiC-PANCf-Ph) composite with 3 wt% SiC enhancement exhibited ideal properties. The post-ablation phase composition and microstructure were examined through X-ray diffraction (XRD), Scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The surface morphology evidences the formation of a silicon dioxide (SiO2) layer on the composites. The SiC-PANCf-Ph composites demonstrated the lowest ablation rate, enhancing their potentiality for effective TPS applications.

Na2Ti3O7@RF@Ag Heterostructures as Efficient Substrates for SERS and Photocatalytic Applications.

A multi-step procedure was effectively employed to synthesize innovative three-dimensional (3D) heterostructures encompassing sodium titanate (Na2Ti3O7) nanowire cores, an intermediate resorcinol-formaldehyde (RF) layer, and outer silver (Ag) nanoparticle sheaths, referred to as Na2Ti3O7@RF@Ag heterostructures. Initially, a one-step hydrothermal technique facilitated the direct growth of single-crystal Na2Ti3O7 nanowires onto a flexible Ti foil. Subsequently, a two-step wet chemical process facilitated the sequential deposition of an RF layer and Ag nanoparticles onto the Na2Ti3O7 nanowires at a low reaction temperature. Optimal concentrations of silver nitrate and L-ascorbic acid can lead to the cultivation of Na2Ti3O7@RF@Ag heterostructures exhibiting heightened surface-enhanced Raman scattering (SERS), which is particularly beneficial for the detection of rhodamine B (RhB) molecules. This phenomenon can be ascribed to the distinctive geometry of the Na2Ti3O7@RF@Ag heterostructures, which offer an increased number of hot spots and surface-active sites, thereby showcasing notable SERS enhancement, commendable reproducibility, and enduring stability over the long term. Furthermore, the Na2Ti3O7@RF@Ag heterostructures demonstrate remarkable follow-up as first-order chemical kinetic and recyclable photocatalysts for the photodecomposition of an RhB solution under UV light irradiation. This result can be attributed to the enhanced inhibition of electron-hole pair recombination and increased surface-active sites.

Mechanisms and factors affecting the removal of minocycline from aqueous solutions using graphene-modified resorcinol formaldehyde aerogels

In recent years, concerns about the presence of pharmaceutical compounds in wastewater have increased. Various types of residues of tetracycline family antibiotic compounds, which are widely used, are found in environmental waters in relatively low and persistent concentrations, adversely affecting human health and the environment. In this study, a resorcinol formaldehyde (RF) aerogel was prepared using the sol–gel method at resorcinol/catalyst ratio of 400 and resorcinol/water ratio of 2 and drying at ambient pressure for removing antibiotics like minocycline. Next, RF aerogel was modified with graphene and to increase the specific surface area and porosity of the modified sample and to form the graphene plates without compromising the interconnected porous three-dimensional structure of the aerogel. Also, the pores were designed according to the size of the minocycline particles on the meso- and macro-scale, which bestowed the modified sample the ability to remove a significant amount of the minocycline antibiotic from the aqueous solution. The removal percentage of the antibiotic obtained by UV–vis spectroscopy. Ultimately, the performance of prepared aerogels was investigated under various conditions, including adsorbent doses (4–10 mg), solution pHs (2–12), contact times of the adsorbent with the adsorbate (3–24 h), and initial concentration of antibiotic (40–100 mg/l). The results from the BET test demonstrated that the surface area of the resorcinol formaldehyde aerogel sample, which included 1 wt% graphene (RF-G1), exhibited an augmentation in comparison to the surface area of the pure aerogel. Additionally, it was noted that the removal percentage of minocycline antibiotic for both the unmodified and altered samples was 71.6% and 92.1% at the optimal pH values of 4 and 6, respectively. The adsorption capacity of pure and modified aerogel for the minocycline antibiotic was 358 and 460.5 mg/g, respectively. The adsorption data for the modified aerogel was studied by the pseudo-second-order model and the results obtained from the samples for antibiotic adsorption with this model revealed a favorable fit, which indicated that the chemical adsorption in the rapid adsorption of the antibiotic by the modified aerogel had occurred.

Facile preparation of high-strength SiC/C aerogels from pre-reacted resorcinol–formaldehyde and siloxane

Carbon aerogels are ideal thermal insulation materials in the field of aerospace. However, their poor oxidative resistance at high temperatures is a significant drawback. Therefore, there is considerable interest in developing SiC/C aerogels. In this study, using pre-reacted resorcinol–formaldehyde gel (RF) as the carbon source, homogeneous silica/phenolic resin (SiO2/RF) hybrid aerogels were prepared via atmospheric pressure drying using a simple process. The SiC/C aerogels were subsequently obtained via carbon thermal reduction. As the C/Si ratio decreased (from 6 to 4.5 and 3), the density, thermal conductivity, and compressive strength of the aerogels decreased from 0.19 to 0.26 g·cm−3, 0.0330 to 0.0983 W/(m·K), and 0.57 to 4.83 MPa, respectively. The linear shrinkage rate was 16.4–18.3 %, which is lower than those of most reported SiC/C aerogels. Here, the carbon improved the strength of the SiC-based aerogels while maintaining their thermal insulation characteristics. A composite material prepared using the relatively low-strength aerogels and mullite fibre felt could achieve long-term insulation at 1400 °C in an air environment. This study lays the foundation and outlines various options for achieving an optimal balance between the strength and thermal conductivity of SiC/C aerogels for industrial applications.

Ag-Containing Carbon Nanocomposites: Physico-Chemical Properties and Antimicrobial Activity

The subject of the present work is the synthesis and analysis of the structural and morphological properties of Ag-containing carbon composites and the investigation of their practical application in water purification and disinfection. A series of composites were synthesized by carbonization of resorcinol–formaldehyde polymers filled with Ag-containing fumed silica under an inert atmosphere at 800 °C. The as-synthesized micro- and mesoporous carbon composites were characterized by their specific surface area of 466–529 m2/g. The suitability of the composites for flow-through filters was evaluated by kinetic studies on the adsorption of 4-chlorophenol. The composite with the highest amount of metallic nanophase showed the most effective kinetics with a rate constant (log k) and half-life (t0.5) of −2.07 and 81 min, respectively. The antimicrobial susceptibility was determined against Gram-positive (Staphylococcus aureus ATCC 25923) and Gram-negative strains (Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 700603, Pseudomonas aeruginosa ATCC 27853, and Acinetobacter baumannii ATCC 19606). The zones of bacterial growth inhibition correlated with the silver nanoparticle content and were the lowest for RFC-02 (10–12 mm) and the highest for the RFC-1 composite (15–16 mm), resulting from the increase in number of evenly distributed small Ag nanoparticles (3–5 nm) in the samples.

Facile preparation of lightweight and robust carbon aerogel monoliths for high-temperature thermal insulation and oil-water separation

Lightweight carbon aerogels (CAs) are urgently required for thermal insulation and organics absorption. However, a facile preparation method of ambient pressure drying (APD) remains a challenge since the large surface tension causes severe shrinkage, collapse or even cracking of porous network. Herein, a series of lightweight, robust and large-sized CA monoliths (0.240–0.327 g/cm3) are prepared through sol-gel polymerization of resorcinol-formaldehyde (RF) followed by solvent exchange-free APD using cotton fibers as reinforcement precursor. The deliberate tailoring of synthesis parameters and the appropriate introduction of cotton fibers jointly bring the advantages of facilitating sol-gel of RF solution.reducing drying shrinkage of hydrogels, and improving compatibility of carbonization shrinkage between fibers and matrix. Consequently, for instance, the CA composite with a density of 0.283 g/cm3, have high compressive strength (3.66 MPa), low thermal conductivity (0.070 W/(m·K)), excellent hydrophobicity (water contact angle as high as 145°), and high-volume organic absorption capability (74.8–95.7%). The facile preparation of CA composites through solvent exchange-free APD with monomer polymerization should be a promising approach to their further application in thermal insulation and oil-water separation.

3-Hydroxythiophenol-Formaldehyde Resin Microspheres Modulated by Sulfhydryl Groups for Highly Efficient Photocatalytic Synthesis of H2O2.

Resorcinol-formaldehyde (RF) resin represents a promising visible-light responding photocatalyst for oxygen reduction reaction (ORR) toward H2O2 production. However, its photocatalytic ORR activity toward H2O2 generation is still unsatisfied for practical application. Herein, 3-hydroxythiophenol-formaldehyde (3-HTPF) resin microspheres synthesized through polycondensation reaction between 3-HTP and formaldehyde at room temperature and subsequent hydrothermal treatment exhibit enhanced photocatalytic ORR activity is reported. The experimental results show that the partial substitution of hydroxy group (─OH) by sulfhydryl one (─SH) through using 3-HTP to replace resorcinol could slow the rates of nucleation and growth of the resin particles and lead to strongly π-stacked architecture in 3-HTPF. The introduction of ─SH group can also improve adsorption ability of 3-HTPF to O2 molecules and enhance ORR catalytic activity of the photocatalysts. Stronger built-in electric field, better adsorption ability to O2 molecules, and increased surface catalytic activity collectively boost photocatalytic activity of 3-HTPF microspheres. As a result, H2O2 production rate of 2010µmh-1 is achieved over 3-HTPF microspheres at 273K, which is 3.4 times larger than that obtained using RF submicrospheres (591µmh-1). The rational substituent group modulation provides a new strategy for designing polymeric photocatalysts at the molecular level toward high-efficiency artificial photosynthesis.

Durability assessment of one-component polyurethane adhesives for bonding of preservative treated wood subject to artificial ageing

Advancements in the use and applications of engineered wood products is receiving much interest in the construction industry. This is because wood has highly credible characteristics in relation to sustainability. It acts as a carbon store and is a natural renewable material. However, achieving adequate durability requirements and ensuring satisfactory adhesive bondline integrity is fundamental for such engineered products particularly when subjected to an exposed exterior service class environment. Little information exists on the durability performance of preservative treated wood bonded using one-component polyurethanes (1C-PURs). This study therefore involved the accelerated ageing of two 1C-PUR adhesives for the bonding of untreated, copper chromate arsenic and micronised copper azole preservative treated wood of fast growing Radiata pine. The ageing involved both vacuum-pressure soak drying cycling and exposure to a constant long-term high temperature and humidity environment. Resorcinol formaldehyde bonded specimens and solid wood specimens were used as controls. The testing showed that the standard requirements for delamination were satisfied when bonding preservative treated wood with 1C-PUR adhesive. The shear strength of specimens bonded with 1C-PUR adhesive subjected to vacuum-pressure soak drying compared well to the performance of the controls. The predominant failure behaviour was wood failure. The shear strength of all bonded preservative treated wood specimens with both 1C-PUR and resorcinol formaldehyde which were exposed to a constant long-term high temperature and humidity environment demonstrated a general and comparable reduction in strength over time which was statistically significant. High wood failure percentages were recorded at the bond interface which indicated weakening of the wood adherend when subject to the ageing rather than weakening of the adhesive bond. Chemical analysis of bonded specimens after ageing demonstrated that no significant variations were experienced.

The role and mechanism of temporary blocked isocyanate at interface between polyethylene terephthalate high‐strength fibers and activation oil

AbstractIn this paper, activation oil added with temporary blocked isocyanate was chosen to enhance interfacial adhesion in polyethylene terephthalate (PET) high‐strength fibers reinforced rubber via one‐step dipping method, in which the temporary blocked isocyanate could be activated during vulcanization process of rubber. The effect of isocyanate in enhancing adhesion between PET high‐strength fibers and rubber was explored. The amount of residual resorcinol formaldehyde latex on the surface of fibers and H‐extraction force of PET high‐strength fibers reinforced rubber are both obviously increased with 5% activation oil addition especially containing 2% isocyanate. After peeling fibers from composite rubber, the amount of residual rubber on the surface of fibers with activation oil is increased, which is even higher when further adding temporary blocked isocyanate. Based on the results of infrared spectra and nuclear magnetic resonance carbon spectra, the added isocyanate is confirmed to bond with the PET component most likely through reacting with the terminal hydroxyl groups on the surface of PET fibers. This interface reinforcement strategy based on one‐step dipping method will contribute to studies on PET high‐strength fibers reinforced rubber.

Influence of Oxyranylmethanol as a Catalytic Cross-linking Agent over Physiochemical Properties and Pb (II) Adsorption Performance of Resorcinol Formaldehyde Aerogels: a Comparative Study

Influence of Oxyranylmethanol as a Catalytic Cross-linking Agent over Physiochemical Properties and Pb (II) Adsorption Performance of Resorcinol Formaldehyde Aerogels: a Comparative Study

The Structure-Function Relationship of Branched Polyethylenimine Impregnated over Mesoporous Carbon Aerogels: An In-Depth Thermogravimetric Insight.

We present a comprehensive thermogravimetric analysis (TGA) of polyethylenimine (PEI)-impregnated resorcinol-formaldehyde (RF) aerogels. While numerous studies focus on PEI-impregnated SBA, RF materials have been less examined, despite their interest and specificities. As most articles on PEI-impregnated porous materials follow typical experimental methods defined for SBA, particularities of RF-PEI materials could remain unheeded. The design of nonisothermal TGA protocols, completed with nitrogen isotherms, based on the systematic filling of the matrix delivers a fundamental understanding of the relationship between the structure and function. This study demonstrates (i) the competition between the matrix and PEI for CO2-physisorption (φ) and CO2-chemisorption (χ), (ii) the hysteresis ([Formula: see text]) of CO2 capture at low temperature attributed to the kinetic (K) hindrance of CO2 diffusion (D) through PEI film/plugs limiting the chemisorption, and (iii) the thermodynamic (θ) equilibrium limiting the capture at high temperature. At variance with SBA-PEI materials, the first layers of PEI in RF are readily available for CO2 capture given that this matrix does not covalently bind PEI as SBA. A facile method allows the discrimination between physi- and chemisorption, exhibiting how the former decreases with PEI coverage. The CO2 capture hysteresis, while seldom introduced or discussed, underlines that the commonly accepted operating temperature of the "maximum capture" is based on an incomplete experiment. Through isotherm adsorption analysis, we correlate the evolution of this maximum to the morphological distribution of PEI. This contribution highlights the specificities of RF-PEI and the advantages of our TGA protocol in understanding the structure/function relationship of this kind of material by avoiding the typical direct applications of SBA-specific protocols. The method is straightforward, does not need large-scale facilities, and is applicable to other materials. Its easiness and rapidness are suited to high-volume studies, befitting for the comprehensive evaluation of interacting factors such as the matrix's nature, pore size, and PEI weight.

Growth Suppression of a Robust Bacterium Methylobacterium extorquens by Porous Materials with Oxygen Functional Groups.

Suppressing the growth of Methylobacterium species without the use of toxic chemicals has been a challenging task owing to their robustness against previous antimicrobial techniques. In this work, we prepared porous materials with various numbers and types of oxygen functional groups and investigated their ability to suppress the growth of Methylobacterium extorquens. It turned out that the number and type of oxygen functional groups in the porous materials greatly affected the growth of the bacterium. Three porous materials (resorcinol-formaldehyde gel (RF), hydrothermally treated RF (RFH), and Wakkanai siliceous shale (WS)) were tested, and RF exhibited the best performance in suppressing the growth of the bacterium. This performance is possibly due to abundant phenolic groups in the porous material.

Characteristics laminates composite bamboo

The main plants in Indonesian people's plantations are apus bamboo (Gigantochloa apus), wulung bamboo (Gigantochloa atroviolacea) and tutul bamboo (Bambusa maculat). Apart from being used as a craft material, bamboo is also suitable for boards in the form of laminated composites bamboo which are usually called laminated bamboo boards. One of the main criteria for laminated bamboo boards is their good adhesion, which is determined by their shear performance (shear strength). The shear strength of laminated bamboo boards is influenced by several factors such as the type of bamboo used, adhesive/matrix type and laminate configuration. This research used three variations of bamboo species: Gigantochloa apus (GA), Gigantochloa atroviolacea (GV) and Bambusa maculat (BM). The matrix/adhesive used is phenol resorcinol formaldehyde (PRF). The bamboo laminated composite arrangement or horizontal configuration is assembled into a three-layer structure using a hand lay up technique. Testing to determine the performance of bamboo laminated composites, with a shear test, using an Instron universal testing machine (UTM) (serial number CP105207), maximum load cell 100 kN with 8 Kg. The results show that the type of bamboo has an effect on the shear performance of bamboo laminate composites. The BM, GV, GA bamboo, respectively, have better performance, greater shear strength.

Facile Preparation of a Novel HfC Aerogel with Low Thermal Conductivity and Excellent Mechanical Properties.

Aerogels emerge as captivating contenders within the realm of high-temperature thermal resistance and thermal insulation. Nevertheless, their practical applications are usually constrained by their inherent brittleness when subjected to rigorous conditions. Herein, employing hafnium dichloride oxide octahydrate (HfOCl2·8H2O) as the hafnium source and resorcinol-formaldehyde (RF) as the carbon precursor, hafnium carbide (HfC) aerogels are fabricated via the sol-gel method complemented with carbothermal reduction reaction. Investigations are conducted into the effects of various molar ratios, duration, and temperatures of calcination on the microstructural features and physico-chemical characteristics of the as-prepared HfC aerogel. The aerogel shows a high BET-specific surface area (601.02 m2/g), which is much larger than those of previously reported aerogels. Furthermore, the HfC aerogel exhibits a low thermal conductivity of 0.053 W/(m·K) and a compressive strength of up to 6.12 MPa after carbothermal reduction at 1500 °C. These excellent thermal insulation and mechanical properties ensure it is ideal for the utilization of high-temperature thermal resistance and thermal insulation in the fields of aerospace.

Microencapsulation of a salt hydrate phase change material by resorcinol formaldehyde through electrohydrodynamic disintegration of coaxially layered filament

Uniform microcapsules of size on the order of 100 nm with CaCl2.6H2O at the core and resorcinol formaldehyde as the shell was made by electro hydrodynamically disintegrating the coaxially layered filament. The shell thickness was varied by changing the flow ratio. The effect of shell thickness on the phase change temperature and the heat flow at its peak value during the DSC scan were reviewed to ascertain the extent of thermal equilibration, and the fraction of PCM melting at the peak value of heat flow. The integrity of the shell was evaluated by sustained dipping in deionized water for a month. The DSC scan was repeated after several heating-cooling cycles to understand the cycle life of the microcapsules.

Fischer‐Tropsch Synthesis by a Cobalt‐Based Carbon Aerogel Catalyst

AbstractCarbon aerogel (CA) as a novel catalyst support in Fischer‐Tropsch synthesis (FTS) was synthesized by polymerization of a resorcinol‐formaldehyde (RF) precursor through an ambient pressure drying route. The cobalt‐doped CA was synthesized by three main strategies: (a) impregnation of the metal precursor on the CA (Co‐CA‐I), (b) carbonization of cobalt‐doped organic RF aerogel (Co‐CA‐II), and (c) addition of the cobalt precursor to the RF mixture (Co‐CA‐III). The pores and cobalt particle size increased in the order of Co‐CA‐I > Co‐CA‐II > Co‐CA‐III and cobalt particles wrapped between the graphite layers when cobalt was added to the RF mixture. The CA as the catalyst support presented high CO conversion and high stability under FTS conditions. The CH4 selectivity increased by reducing the size of the cobalt particles. Hydrogen spillover from the support to metallic particles was observed in the case of Co‐CA‐I and Co‐CA‐III catalysts. This phenomenon improved the reducibility and also resulted in higher hydrogenated products being produced.

Iron-based resin heterogeneous photo-self-Fenton system for efficient photocatalytic degradation of antibiotic wastewater

The homogeneous Fenton reaction is limited by its pH requirements for the addition of the iron source and by the safety risks of working with high concentrations of hydrogen peroxide (H2O2) - both of which are major obstacles in the path toward utilizing this reaction for practical applications. In this study, we present a novel heterogeneous photo-self-Fenton system of iron-doped resorcinol formaldehyde (FRF) resin. This system is able to generate and utilize H2O2 in-suit, making it highly efficient at degrading and mineralizing various types of antibiotics (macrolides, sulfonamides, tetracyclines, quinolones) at a neutral pH without the need for additional reagents. Remarkably, the degradation rate constant of oxytetracycline (OTC) increased by 34.2 times compared to the resorcinol formaldehyde (RF) photocatalysis. The enhanced degradation performance of this system is attributed to (i) The Iron-anchored RF, which facilitates the rapid transfer of photogenerated electrons, thereby accelerating the recycling of iron ions and improving the migration and separation efficiency of photogenerated carriers. (ii) The heterogeneous photo-self-Fenton reaction using in situ generated H2O2 to produce abundant hydroxyl radicals. Finally, the mechanism of action and the mineralization pathway of OTC were systematically studied. The OTC undergoes demethylation, hydroxylation, and ring-opening and ultimately is completely mineralized to CO2 and H2O. The work provides a new sustainable pathway for extensively constructing heterogeneous photo-self-Fenton systems.

MOFs-derived Co-Fe sulfides as highly efficient and stable catalysts to activate peroxymonosulfate for the degradation of trichlorophenol

Advanced oxidation processes activated by transition metal have attracted much attention for their excellent performance in the removal of organic pollutants, but the development of efficient and environmentally benign catalysts is still a significant challenge. In this work, carbon shell encapsulating Co/Fe sulfide nanoparticles (Co/Fe@SCX) were synthesized by pyrolysis of the resorcinol-formaldehyde (RF) coated MIL-101 @ZIF-67 bimetal Metal-organic frameworks (MOFs). In the degradation of TCP, Co/Fe@SC600 exhibited the highest TCP removal rate (97.33%) and reaction rate constant (kobs) (0.169 min−1), as well as the mineralization rate of up to 60.19%. Compared to other prepared catalysts, Co/Fe@SC600 not only possessed excellent catalytic activity, but also exhibited the lowest Co ion leaching concentration, good stability and high resistance to environmental factors. Further studies showed that the non-radical pathway dominated by 1O2 contributed most to the TCP degradation, and the radicals also played the indispensable role. The potential TCP degradation pathways in the reaction system was also investigated by analyzing the intermediate products during the degradation process. Overall, this study may provide some interesting insights into the design of advanced catalysts.