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ZnO nanorod arrays assembled on activated carbon fibers for photocatalytic degradation: Characteristics and synergistic effects

Well-aligned ZnO nanorod arrays were assembled on activated carbon[url=https://www.yrdcarbon.com/]yongruida activated charcoal[/url] fibers by a stepwise sequence of sol-gel and hydrothermal synthesis methods. These ZnO nanorod arrays on activated carbon fibers having different characteristics such as surface area, rod concentration, aspect ratio and defect level, were applied as catalysts for the photodegradation of an aqueous methylene blue solution. They showed very promising methylene blue adsorbility in the dark (ca. 0.025-0.031 mg methylene blue m-2 catalyst, vs. 0.072 mg methylene blue m-2 activated carbon fibers). Significantly, the defect level of ZnO nanorod arrays has a major effect on the turnover frequency compared to other characteristics. A synergistic effect between activated carbon fibers and ZnO nanocrystals on enhancing turnover frequency was more significant for the well-assembled ZnO nanorod arrays on activated carbon fibers catalysts compared to the mechanically mixed ZnO powder with activated carbon fibers catalyst. Further, turnover frequency for the ZnO nanorod arrays on activated carbon fibers (0.00312 molmethylene blue molZnO-1 h-1) was twice higher than that for the corresponding bare ZnO nanorod arrays, and 3 times higher than that for a commercial ZnO powder. In addition, ZnO nanorod arrays on activated carbon fibers show high degradation (77.5%) and mineralization (55.0%) levels for methylene blue, and also good reusability (or stability) as demonstrated by a sequential 5-time recycle routine. These outstanding features indicate that activated carbon[url=https://www.yrdcarbon.com/products/activated-carbon/]wholesale active carbon[/url] fibers supported ZnO nanorod arrays have significant potential to be used as catalysts for photodegradation.

Direct observation of solid-phase adsorbate concentration profile in powdered activated carbon particle to elucidate mechanism of high adsorption capacity on super-powdered activated carbon

Decreasing the particle size of powdered activated carbon (PAC)[url=https://www.powdered-activated-carbon.com/]yongruida activated carbon powder[/url] by pulverization increases its adsorption capacities for natural organic matter (NOM) and polystyrene sulfonate (PSS, which is used as a model adsorbate). A shell adsorption mechanism in which NOM and PSS molecules do not completely penetrate the adsorbent particle and instead preferentially adsorb near the outer surface of the particle has been proposed as an explanation for this adsorption capacity increase. In this report, we present direct evidence to support the shell adsorption mechanism. PAC particles containing adsorbed PSS were sectioned with a focused ion beam, and the solid-phase PSS concentration profiles of the particle cross-sections were directly observed by means of field emission–scanning electron microscopy/energy-dispersive X-ray spectrometry (FE-SEM/EDXS). X-ray emission from sulfur, an index of PSS concentration, was higher in the shell region than in the inner region of the particles. [url=https://www.activated-carbon-pellets.com/]www.activated-carbon-pellets.com[/url]The X-ray emission profile observed by EDXS did not agree completely with the solid-phase PSS concentration profile predicted by shell adsorption model analysis of the PSS isotherm data, but the observed and predicted profiles were not inconsistent when the analytical errors were considered. These EDXS results provide the first direct evidence that PSS is adsorbed mainly in the vicinity of the external surface of the PAC particles, and thus the results support the proposition that the increase in NOM and PSS adsorption capacity with decreasing particle size is due to the increase in external surface area on which the molecules can be adsorbed.

A study on sliding and erosive wear behaviour of atmospheric plasma sprayed conventional and nanostructured alumina coatings

[url=https://www.hslabrasive.com/products/fused-alumina/]fused alumina suppliers[/url]Alumina coatings on stainless steel substrate (SS304) were deposited by using atmospheric plasma spray technique with a feed stock of manually granulated and sieved nano Al2O3 powder. The hardness, sliding, and erosive wear of the nanostructured alumina coatings (NC) were investigated and compared with that of conventional alumina coatings (CC). Pin-on disc type sliding wear test on the alumina coatings (NC and CC) was performed with load varying from 30 N to 80 N at a sliding speed of 0.5 m/s. Pot type slurry erosion test of the coatings was conducted for different concentrations of Al2O3 and a mixture of Al2O3 and SiO2 slurry. The microstructural features of both NC and CC of alumina were characterized by using FE-SEM/EDS and SEM analysis to substantiate the failure of coatings due to wear. Wear and erosion resistance of nano alumina coating is better than the conventional alumina coating as observed in the present work. [url=https://www.hslabrasive.com/]https://hslabrasive.com[/url]The bimodal structure of NC contributes for the enhanced wear resistance. The high fracture toughness of NC is due to suppression of cracks by partially melted particles in the coatings.

Direct observation of solid-phase adsorbate concentration profile in powdered activated carbon particle to elucidate mechanism of high adsorption capacity on super-powdered activated carbon

Decreasing the particle size of powdered activated carbon (PAC) [url=https://www.powdered-activated-carbon.com/]yongruida activated carbon powder[/url]by pulverization increases its adsorption capacities for natural organic matter (NOM) and polystyrene sulfonate (PSS, which is used as a model adsorbate). A shell adsorption mechanism in which NOM and PSS molecules do not completely penetrate the adsorbent particle and instead preferentially adsorb near the outer surface of the particle has been proposed as an explanation for this adsorption capacity increase. In this report, we present direct evidence to support the shell adsorption mechanism. PAC particles containing adsorbed PSS were sectioned with a focused ion beam, and the solid-phase PSS concentration profiles of the particle cross-sections were directly observed by means of field emission–scanning electron microscopy/energy-dispersive X-ray spectrometry (FE-SEM/EDXS). X-ray emission from sulfur, an index of PSS concentration, was higher in the shell region than in the inner region of the particles. The X-ray emission profile observed by EDXS did not agree completely with the solid-phase PSS concentration profile predicted by shell adsorption model analysis of the PSS isotherm data, but the observed and predicted profiles were not inconsistent when the analytical errors were considered. These EDXS results provide the first direct evidence that PSS is adsorbed mainly in the vicinity of the external surface of the PAC[url=https://www.activated-carbon-pellets.com/]www.activated-carbon-pellets.com[/url] particles, and thus the results support the proposition that the increase in NOM and PSS adsorption capacity with decreasing particle size is due to the increase in external surface area on which the molecules can be adsorbed.

Enrichment of the surface functional groups of activated carbon by modification method

The wastes formed from various industries' activities draw attention to their ability to be used as a natural adsorbent or as a source for activated carbon[url=https://www.yrdcarbon.com/]yongruida activated charcoal[/url] production. In this study, we aimed to produce activated carbon rich in surface functional groups from biomass. Surface functional groups of activated carbons (AC) were enriched by HNO3 oxidation. The activated carbons were synthesized with H3PO4 using peach stones (PSs), fruit juice industrial wastes, and can be found in abundance in the World and Turkey. The activated carbons' surface properties, such as BET surface area, micro-mesopore volume, and average pore diameter, were determined. The activated carbon with the highest surface area was produced with the impregnation ratio of 3/1 at 400 °C (3AC400) as 1399 m2/g. The microporous structures of the 3AC400 synthesized were determined to be more than the mesopore structures. The effects of acid modification on the surface of 3AC400, whose surface characterization was completed, were investigated using HNO3 at different concentrations (15, 30, 45, and 69% (v/v) HNO3). When the nitric acid concentration used in the modification was increased from 15% to 69%, the BET surface area of pure activated carbon (3AC400) decreased from 1399 m2/g to 15.44 m2/g. Besides, the micropores were wholly clogged, and the mesopore volume decreased from 0.127 cm3/g to 0.042 cm3/g. Vmic/Vtop of 3AC400 was reduced from 0.813 to 0.008. Modification using in this study was found to have a significant effect on the surface area of 3AC400. Nitric acid led micropores to collapse. So the structure of the surface of modified activated carbons has become more mesopores. The surface properties and surface functional group diversity of the synthesized modified activated carbons by various methods were investigated. With 69% nitric acid modification, the amount of carboxyl, lactone, and phenyl groups on the activated carbon surface was increased by 5.3, 9.75, and 9.00, respectively. [url=https://www.yrdcarbon.com/products/activated-carbon/]wholesale active carbon[/url]The nitric acid modification affected the diversity of surface functional groups such as lactone> phenol> carboxyl. As the nitric acid concentration increased, the modified samples' total surface acidity increased, and IEP values shifted from 3.6 to the left. The total acidity value for the 69NAC/90/2 sample has increased approximately seven times that of the total acidity value of 3AC400.

Comparative tribological study of plasma sprayed alumina and alumina-yttria under severe conditions

In the current study, alumina and[url=https://www.hslabrasive.com/products/fused-alumina/brown-fused-alumina.html]brown fused alumina HSL[/url]alumina-yttria composite coatings were prepared on stainless steel substrates via atmospheric plasma spraying. Their dry sliding wear performances against graphite under severe conditions were evaluated by using a ring-on-disk tribometer. The results showed that the addition of yttria has successfully decreased the friction coefficients of the alumina coatings. Further, the temperatures in the friction process rose sharply in the initial wear stage and then reached the state of thermal equilibrium. The temperatures of alumina-yttria coatings at thermal equilibrium stages were lower than those of alumina coatings, which may be due to their lower friction combined with the slightly higher thermal conductivity. High friction interface temperatures were considered to greatly aggravate the thermal stress, thereby intensifying the cracking of alumina coatings. [url=https://www.hslabrasive.com/]HSL factory[/url]Additionally, the addition of yttria improved the toughness of composite coatings and the related crack propagation resistance.

Coffee-derived activated carbon from second biowaste for supercapacitor applications

The electrochemical energy storage performance of [url=https://www.activated-carbon-pellets.com/]bulk activated virgin carbon pellets[/url]activated carbons (ACs) obtained from coffee-derived biowastes was assessed. ACs were obtained from spent coffee ground second waste, after polyphenol extraction, by means of a hydrothermal process followed by physical or chemical activation. The resulting materials exhibited microporous structures with a total specific area between 585 and 2330 m2·g−1. Scanning electron microscopy (SEM) revealed a highly porous microstructure in the case of the chemically activated carbons, while physical activation led to a cracked micro-sized morphology. The electrochemical properties of the materials for supercapacitor applications were investigated in 1 M Na2SO4. After chemical activation, the coffee-derived material displayed a capacitance of 84 F·g−1 at 1 A·g−1 in a 1.9 V voltage window, with 70% capacitance retention at 10 A·g−1 and 85% retention after 5000 cycles of continuous charge-discharge. This work demonstrates how coffee secondary biowaste can be conveniently activated to perform as electrochemical energy storage material,[url=https://www.powdered-activated-carbon.com/]activated carbon powder for sale[/url] contributing to its revalorization and reinsertion in a circular economy.

Polypyrrole-Grafted Coconut Shell Biological Carbon as a Potential Adsorbent for Methyl Tert-Butyl Ether Removal: Characterization and Adsorption Capability

[url=https://www.chinactivecarbon.com/products/coconut-carbon-gold.html]coconut activated carbon gold[/url]Methyl tert-butyl ether (MTBE) has been used as a common gasoline additive worldwide since the late twentieth century, and it has become the most frequently detected groundwater pollutant in many countries. This study aimed to synthesize a novel microbial carrier to improve its adsorptive capacity for MTBE and biofilm formation, compared to the traditional granular activated carbon (GAC). A polypyrrole (PPy)-modified GAC composite (PPy/GAC) was synthesized, and characterized by Fourier transform infrared spectroscopy (FT-IR) and Brunauer-Emmett-Teller (BET) surface area analysis. The adsorption behaviors of MTBE were well described by the pseudo-second-order and Langmuir isotherm models. Furthermore, three biofilm reactors were established with PPy/GAC, PPy, and GAC as the carriers, respectively, and the degradation of MTBE under continuous flow was investigated. Compared to the biofilm reactors with PPy or GAC (which both broke after a period of operation),[url=https://www.chinactivecarbon.com/]activated carbon price[/url] the PPy/GAC biofilm column produced stable effluents under variable treatment conditions with a long-term effluent MTBE concentration <20 μg/L. Pseudomonas aeruginosa and Acinetobacter pittii may be the predominant bacteria responsible for MTBE degradation in these biofilm reactors.

Photothermal desorption of single-walled carbon nanotubes and coconut shell-activated carbons using a continuous light source for application in air sampling

[url=https://www.chinactivecarbon.com/products/coconut-carbon-gold.html]coconut activated carbon gold[/url]Many techniques exist to measure airborne volatile organic compounds (VOCs), each with differing advantages; sorbent sampling is compact, versatile, has good sample stability, and is the preferred technique for collecting VOCs for hygienists. Development of a desorption technique that allows multiple analyses per sample (similar to chemical desorption) with enhanced sensitivity (similar to thermal desorption) would be helpful to field hygienists. In this study, activated carbon (AC) and single-walled carbon nanotubes (SWNT) were preloaded with toluene vapor and partially desorbed with light using a common 12-V DC, 50-W incandescent/halogen lamp. A series of experimental chamber configurations were explored starting with a 500-ml chamber under static conditions, then with low ventilation and high ventilation, finally a 75-ml high ventilation chamber was evaluated. When preloaded with toluene and irradiated at the highest lamp setting for 4min, AC desorbed 13.9, 18.5, 23.8, and 45.9% of the loaded VOC mass, in each chamber configuration, respectively; SWNT desorbed 25.2, 24.3, 37.4, and 70.5% of the loaded VOC mass, respectively. SWNT desorption was significantly greater than AC in all test conditions (P = 0.02-<0.0001) demonstrating a substantial difference in sorbent performance. When loaded with 0.435mg toluene and desorbed at the highest lamp setting for 4min in the final chamber design, the mean desorption for AC was 45.8% (39.7, 52.0) and SWNT was 72.6% (68.8, 76.4) (mean represented in terms of 95% confidence interval). All desorption measurements were obtained using a field grade photoionization detector;[url=https://www.chinactivecarbon.com/]activated carbon price[/url] this demonstrates the potential of using this technique to perform infield prescreening of VOC samples for immediate exposure feedback and in the analytical lab to introduce sample to a gas chromatograph for detailed analysis of the sample.

Direct observation of solid-phase adsorbate concentration profile in powdered activated carbon particle to elucidate mechanism of high adsorption capacity on super-powdered activated carbon

Decreasing the particle size of powdered activated carbon (PAC)[url=https://www.powdered-activated-carbon.com/]activated carbon powder for sale[/url] by pulverization increases its adsorption capacities for natural organic matter (NOM) and polystyrene sulfonate (PSS, which is used as a model adsorbate). A shell adsorption mechanism in which NOM and PSS molecules do not completely penetrate the adsorbent particle and instead preferentially adsorb near the outer surface of the particle has been proposed as an explanation for this adsorption capacity increase. In this report, we present direct evidence to support the shell adsorption mechanism. PAC particles containing adsorbed PSS were sectioned with a focused ion beam, and the solid-phase PSS concentration profiles of the particle cross-sections were directly observed by means of field emission–scanning electron microscopy/energy-dispersive X-ray spectrometry (FE-SEM/EDXS). X-ray emission from sulfur, an index of PSS concentration, was higher in the shell region than in the inner region of the particles. The X-ray emission profile observed by EDXS did not agree completely with the solid-phase PSS concentration profile predicted by shell adsorption model analysis of the PSS isotherm data, but the observed and predicted profiles were not inconsistent when the analytical errors were considered. These EDXS results provide the first direct evidence that PSS is adsorbed mainly in the vicinity of the external surface of the PAC[url=https://www.activated-carbon-pellets.com/]bulk activated virgin carbon pellets[/url] particles, and thus the results support the proposition that the increase in NOM and PSS adsorption capacity with decreasing particle size is due to the increase in external surface area on which the molecules can be adsorbed.


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