Impact of Doping and Additive Applications on Photocatalyst Textural Properties in Removing Organic Pollutants: A Review

The effect of ion doping and the incorporation of additives on photocatalysts’ textural properties have been reviewed. Generally, it can be summarised that ion doping and additives have beneficial effects on photocatalytic efficiency and not all have an increase in the surface area. The excessive amount of dopants and additives will produce larger aggregated particles and also cover the mesoporous structures, thereby increasing the pore size (Pd) and pore volume (Pv). An excessive amount of dopants also leads to visible light shielding effects, thus influence photocatalytic performance. Ion doping also shows some increment in the surface areas, but it has been identified that synergistic effects of the surface area, porosity, and dopant amount contribute to the photocatalytic performance. It is therefore important to understand the effect of doping and the application of additives on the textural properties of photocatalysts, thus, their performance. This review will provide an insight into the development of photocatalyst with better performance for wastewater treatment applications.

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Insight into the factors influencing the photocatalytic H2 evolution performance of molybdenum sulfide

New Journal of Chemistry ◽

10.1039/c8nj04639e ◽

2019 ◽

Vol 43 (3) ◽

pp. 1230-1237 ◽

Cited By ~ 4

Author(s):

Mingcai Yin ◽

Wenli Zhang ◽

Hui Li ◽

Chaojun Wu ◽

Fangfang Jia ◽

...

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Photocatalytic Performance ◽

Molybdenum Sulfide ◽

H2 Evolution ◽

Key Factors ◽

Factors Influencing ◽

Insight Into ◽

Photocatalytic H2 Evolution

The specific surface area and composition are found to be the key factors influencing the photocatalytic performance of MoS2+x.

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A Case Study of Waste Scrap Tyre-Derived Carbon Black Tested for Nitrogen, Carbon Dioxide, and Cyclohexane Adsorption

Molecules ◽

10.3390/molecules25194445 ◽

2020 ◽

Vol 25 (19) ◽

pp. 4445 ◽

Cited By ~ 1

Author(s):

Zuzana Jankovská ◽

Marek Večeř ◽

Ivan Koutník ◽

Lenka Matějová

Keyword(s):

Activated Carbon ◽

Carbon Black ◽

Specific Surface ◽

Surface Area ◽

Sorption Capacity ◽

Specific Surface Area ◽

Textural Properties ◽

Pyrolytic Carbon ◽

Surface Areas ◽

Wide Range

Waste scrap tyres were thermally decomposed at the temperature of 600 °C and heating rate of 10 °C·min−1. Decomposition was followed by the TG analysis. The resulting pyrolytic carbon black was chemically activated by a KOH solution at 800 °C. Activated and non-activated carbon black were investigated using high pressure thermogravimetry, where adsorption isotherms of N2, CO2, and cyclohexane were determined. Isotherms were determined over a wide range of pressure, 0.03–4.5 MPa for N2 and 0.03–2 MPa for CO2. In non-activated carbon black, for the same pressure and temperature, a five times greater gas uptake of CO2 than N2 was determined. Contrary to non-activated carbon black, activated carbon black showed improved textural properties with a well-developed irregular mesoporous-macroporous structure with a significant amount of micropores. The sorption capacity of pyrolytic carbon black was also increased by activation. The uptake of CO2 was three times and for cyclohexane ten times higher in activated carbon black than in the non-activated one. Specific surface areas evaluated from linearized forms of Langmuir isotherm and the BET isotherm revealed that for both methods, the values are comparable for non-activated carbon black measured by CO2 and for activated carbon black measured by cyclohexane. It was found out that the N2 sorption capacity of carbon black depends only on its specific surface area size, contrary to CO2 sorption capacity, which is affected by both the size of specific surface area and the nature of carbon black.

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Valorization of cellulose-doped lignin: application of cellulose-doped lignin-derived activated carbon in capacitors and investigation of its textural properties and electrochemical performance

10.21203/rs.3.rs-279922/v1 ◽

2021 ◽

Author(s):

Liangcai Wang ◽

Xin Feng ◽

Huanhuan Ma ◽

Jielong Wu ◽

Yu Chen ◽

...

Keyword(s):

Activated Carbon ◽

Specific Surface ◽

Specific Capacitance ◽

Surface Area ◽

Specific Surface Area ◽

Wall Thickness ◽

Textural Properties ◽

Pore Wall ◽

Surface Areas ◽

Pore Wall Thickness

Abstract This work provides an idea for efficient and harmless utilization of lignin and further evaluated the textural properties of lignin-derived activated carbon/specific capacitance relationship. The yield of cellulose-doped apricot shell lignin (ASLC) was 30.42%. H3PO4/KOH was used to assist the preparation of ASLC-derived activated carbon (AAC) for capacitors. The specific surface areas of the as-obtained AAC-P-3 and AAC-K-2 were 1475.16 m2/g and 2136.56 m2/g, respectively. The specific capacitances of AAC-P-3 and AAC-K-2 were 169.14 F/g and 236.00 F/g, respectively, upon the current density of 0.50 A/g. In capacitors containing aqueous KOH as the electrolyte, the AR2 (0.983) between specific surface area and specific capacitance was highest, followed by the AR2 (0.978) between Vmicro/Vmeso and specific capacitance, the AR2 (0.975) between pore-wall thickness and specific capacitance. Consequently, the specific capacitances of the AACs depend not only the specific surface area, but also on the Vmicro/Vmeso, pore-wall thickness, and Vmicro.

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Effects of iron ions, doping methods and nanotubular morphology on TiO2 solar photocatalytic performance

Water Science & Technology ◽

10.2166/wst.2021.182 ◽

2021 ◽

Author(s):

Rafik Melki ◽

Nadia Aïcha Laoufi ◽

Abdelkader Mouheb

Keyword(s):

Surface Area ◽

Hydroxyl Radicals ◽

Photocatalytic Performance ◽

Catalyst Surface ◽

Morphological Changes ◽

Adsorption Properties ◽

Activation Process ◽

Iron Ions ◽

Catalyst Activation ◽

Ion Doping

Abstract The effects of Fe2+ and Fe3+ as TiO2 cocatalysts were studied, and the experimental results showed that Fe3+ was more efficient than Fe2+, which needed an intermediate reaction to produce hydroxyl radicals. TiO2 was modified with the aim of improving its structural, optical, and adsorption properties, thus improving its photocatalytic performance. The light range of the catalyst activation process was expanded, which increased the catalyst's ability to absorb visible light. Consequently, this study exploits solar energy in photocatalysis by Fe ion doping using different methods, including impregnation, photodeposition, solvothermal doping, and hydrothermal doping, and evaluates the influence of each doping method on TiO2 optical properties and photocatalytic activity. Enhancing the catalyst adsorption capacity by morphologically modifying TiO2 nanoparticles into nanotubes using the hydrothermal method increases the catalyst surface area from 55 to 294 m2/g, as shown in the MEB and BET results. The effect of combining morphological changes and Fe3+ doping on TiO2 activity was evaluated. We observed a reduction in the TiO2 band gap from 3.29 to 3.01 eV, absorption edge widening, and an increase in the specific surface area up to 279 m2/g; thus, the synthesized catalyst eliminated Cefixime in 120 min.

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Kinetic of sintering of polyethilene glycol and lanthanum dopped aluminum oxide obtained by the sol-gel method

Hemijska industrija ◽

10.2298/hemind110406031n ◽

2011 ◽

Vol 65 (4) ◽

pp. 355-362

Author(s):

Tatjana Novakovic ◽

Ljiljana Rozic ◽

Zorica Vukovic ◽

Srdjan Petrovic

Keyword(s):

Heat Treatment ◽

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Initial Period ◽

Sol Gel ◽

Textural Properties ◽

Sintering Behavior ◽

Isothermal Heat Treatment ◽

Surface Areas

Sintering and crystallization of low-density polyethylene glycol (PEG) and lanthanum, La(III)-doped Al2O3 aerogels prepared from aluminum isopropoxide were investigated. The sintering behavior of non-doped and doped aerogels was examined by following the change of specific surface area with isothermal heat-treatment. The specific surface area and crystalline phases of non-doped and PEG+La(III)-doped aerogels were determined, and the effects of dopants on the sintering and crystallization of Al2O3 aerogels are discussed. Isothermal sintering experiments showed that the sintering mechanism of non-doped and PEG+La(III)-doped Al2O3 aerogels is surface diffusion. The specific surface areas of alumina samples decrease rapidly during the initial period of sintering, and more slowly with prolonged sintering time. The change of the porous structure is correlated with the phase transformation of ?-Al2O3 during calcinations of Al2O3 aerogels. The surface area of non-doped Al2O3 aerogels came to about 20 m2g-1 with heat-treatment at 1100?C because of crystallization of ?-Al2O3 after densification. In the case of heattreatment at 1200?C, the largest surface area was observed for PEG+La(III) doped Al2O3 aerogels and the XRD pattern showed only low ordered ?-Al2O3. These indicate that the addition of PEG+La(III) to boehmite sol prevents Al2O3 aerogels from sintering and crystallizing to the ?-Al2O3 phase. Even after 20 h at 1000?C, PEG+La (III)-doped alumina samples maintain a rather good specific surface area (108 m2 g-1) in comparison to the non-doped, containing mainly ?-Al2O3 and minor amounts of ?-Al2O3. Aluminum-oxides with these structural and textural properties are widely used as a coatings and catalyst supports in the field of various catalysis.

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Photocatalytic Performance of SnO2 Prepared by Different Precipitants

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.331.540 ◽

2013 ◽

Vol 331 ◽

pp. 540-543

Author(s):

Sheng Tian Huang ◽

Jun Bo Zhong ◽

Jian Zhang Li ◽

Wei Hu

Keyword(s):

Photocatalytic Activity ◽

Specific Surface ◽

Surface Area ◽

Diffuse Reflectance ◽

Photocatalytic Performance ◽

Strong Dependence ◽

Bet Surface Area ◽

Surface Areas ◽

Specific Surface Areas ◽

Average Size

Parallel flow precipitation has been employed to prepare nanostructured SnO2. It is found that the specific surface areas and photocatalytic performance of SnO2 has a strong dependence on the kind of precipitant. The prepared photocatalysts were characterized by BET, XRD, UV-Vis diffuse reflectance and SEM. The results show that SnO2 prepared by NH3·H2O + (NH4)2CO3 has the highest BET surface area and the smallest crystal average size. SnO2 prepared by NH3·H2O + (NH4)2CO3 exhibits the best photocatalytic activity. The results of further experiments show that the specific surface area plays an important role in promotion of photocatalytic activity of SnO2 prepared by NH3·H2O + (NH4)2CO3.

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Cell morphology, volume, and surface area determinations from multilevel contouring within HVEM micrographs of serial sections and whole-cell mounts

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100127426 ◽

1987 ◽

Vol 45 ◽

pp. 588-589

Author(s):

M. Marko ◽

A. Leith ◽

D. Parsons

Keyword(s):

Surface Area ◽

Electron Micrographs ◽

Cell Morphology ◽

Individual Variation ◽

Serial Section ◽

Stereo Pair ◽

Complex Structures ◽

Serial Sections ◽

Surface Areas ◽

Computer Based

The use of serial sections and computer-based 3-D reconstruction techniques affords an opportunity not only to visualize the shape and distribution of the structures being studied, but also to determine their volumes and surface areas. Up until now, this has been done using serial ultrathin sections.The serial-section approach differs from the stereo logical methods of Weibel in that it is based on the Information from a set of single, complete cells (or organelles) rather than on a random 2-dimensional sampling of a population of cells. Because of this, it can more easily provide absolute values of volume and surface area, especially for highly-complex structures. It also allows study of individual variation among the cells, and study of structures which occur only infrequently.We have developed a system for 3-D reconstruction of objects from stereo-pair electron micrographs of thick specimens.

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A Molecular Insight into the Synergistic Mechanism of Nigella sativa (Black Cumin) with β-Lactam Antibiotics against Clinical Isolates of Methicillin-Resistant Staphylococcus aureus

Applied Sciences ◽

10.3390/app11073206 ◽

2021 ◽

Vol 11 (7) ◽

pp. 3206

Author(s):

Lorina I. Badger-Emeka ◽

Promise Madu Emeka ◽

Hairul Islam M. Ibrahim

Keyword(s):

Staphylococcus Aureus ◽

Mechanism Of Action ◽

Methicillin Resistant Staphylococcus Aureus ◽

Nigella Sativa ◽

Synergistic Effects ◽

Diffusion Method ◽

Methicillin Resistant ◽

Cell Wall Disruption ◽

Time Kill ◽

Insight Into

Methicillin-resistant Staphylococcus aureus (MRSA) infection is detrimental to hospitalized patients. With diminishing choices of antibiotics and the worry about resistance to colistin in synergistic combined therapy, there are suggestions for the use of herbal derivatives. This investigation evaluated the synergistic effects of Nigella sativa (NS) in combination with beta-lactam (β-lactam) antibiotics on extreme drug-resistant (XDR) MRSA isolates. NS concentrations of 10, 7.5, 5.0, 2.5, 1.0, and 0.1 µg/mL, alone and in combination with β-lactam antibiotics, were used to determine the antimicrobial susceptibility of MRSA isolates by the well diffusion method. Time–kill assays were performed using a spectrophotometer, with time–kill curves plotted and synergism ascertained by the fractional inhibitory concentration (FIC). Scanning and transmission electron microscopy were used to gain insight into the mechanism of action of treated groups. Isolates were inhibited by the NS concentrations, with differences in the zones of inhibition being statistically insignificant at p < 0.05. There were statistically significant differences in the time–kill assay for the MRSA isolates. In addition, NS combined with augmentin showed better killing than oxacillin and cefuroxime. The mechanism of action shown by the SEM and TEM results revealed cell wall disruption, which probably created interference that led to bacterial lysis.

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Tuning the hierarchical pore structure of graphene oxide through dual thermal activation for high-performance supercapacitor

Scientific Reports ◽

10.1038/s41598-021-81759-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jeongpil Kim ◽

Jeong-Hyun Eum ◽

Junhyeok Kang ◽

Ohchan Kwon ◽

Hansung Kim ◽

...

Keyword(s):

Graphene Oxide ◽

Pore Structure ◽

Specific Capacitance ◽

Surface Area ◽

Thermal Annealing ◽

High Performance ◽

Annealing Process ◽

Supercapacitor Electrode ◽

Simple Method ◽

Surface Areas

AbstractHerein, we introduce a simple method to prepare hierarchical graphene with a tunable pore structure by activating graphene oxide (GO) with a two-step thermal annealing process. First, GO was treated at 600 °C by rapid thermal annealing in air, followed by subsequent thermal annealing in N2. The prepared graphene powder comprised abundant slit nanopores and micropores, showing a large specific surface area of 653.2 m2/g with a microporous surface area of 367.2 m2/g under optimized conditions. The pore structure was easily tunable by controlling the oxidation degree of GO and by the second annealing process. When the graphene powder was used as the supercapacitor electrode, a specific capacitance of 372.1 F/g was achieved at 0.5 A/g in 1 M H2SO4 electrolyte, which is a significantly enhanced value compared to that obtained using activated carbon and commercial reduced GO. The performance of the supercapacitor was highly stable, showing 103.8% retention of specific capacitance after 10,000 cycles at 10 A/g. The influence of pore structure on the supercapacitor performance was systematically investigated by varying the ratio of micro- and external surface areas of graphene.

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Precise regulation of the relative rates of surface area and volume synthesis in bacterial cells growing in dynamic environments

Nature Communications ◽

10.1038/s41467-021-22092-5 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Handuo Shi ◽

Yan Hu ◽

Pascal D. Odermatt ◽

Carlos G. Gonzalez ◽

Lichao Zhang ◽

...

Keyword(s):

Growth Rate ◽

Time Delay ◽

Surface Area ◽

Environmental Changes ◽

Volume Ratio ◽

Dynamic Environments ◽

Bacterial Cells ◽

Bacterial Growth Rate ◽

State Size ◽

Insight Into

AbstractThe steady-state size of bacterial cells correlates with nutrient-determined growth rate. Here, we explore how rod-shaped bacterial cells regulate their morphology during rapid environmental changes. We quantify cellular dimensions throughout passage cycles of stationary-phase cells diluted into fresh medium and grown back to saturation. We find that cells exhibit characteristic dynamics in surface area to volume ratio (SA/V), which are conserved across genetic and chemical perturbations as well as across species and growth temperatures. A mathematical model with a single fitting parameter (the time delay between surface and volume synthesis) is quantitatively consistent with our SA/V experimental observations. The model supports that this time delay is due to differential expression of volume and surface-related genes, and that the first division after dilution occurs at a tightly controlled SA/V. Our minimal model thus provides insight into the connections between bacterial growth rate and cell shape in dynamic environments.

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