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

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.

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

Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1160
Author(s):  
Safia Syazana Mohtar ◽  
Farhana Aziz ◽  
Ahmad Fauzi Ismail ◽  
Nonni Soraya Sambudi ◽  
Hamidah Abdullah ◽  
...  
Keyword(s):  
Surface Area ◽  
Photocatalytic Performance ◽  
Synergistic Effects ◽  
Textural Properties ◽  
Excessive Amount ◽  
Beneficial Effects ◽  
Surface Areas ◽  
Ion Doping ◽  
Insight Into ◽  
Shielding Effects

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.

A simple tactic synthesis of hollow porous graphitic carbon nitride with significantly enriched photocatalytic performance

2021 ◽  
Author(s):  
Vellaichamy Balakumar ◽  
Manivannan Ramalingam ◽  
Chitiphon Chuaicham ◽  
KARTHIKEYAN SEKAR ◽  
K. Sasaki
Keyword(s):  
Crystal Structure ◽  
Surface Area ◽  
Carbon Nitride ◽  
Photocatalytic Performance ◽  
Porous Graphitic Carbon ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Modified Surface

Hollow porous graphitic carbon nitride (porous CN) was synthesized via a simple tactic method, and the resulting porous CN showed an effectively modified surface area, crystal structure and enhanced photocatalytic...

Physico-Chemical and Morphological Changes of Sayong Kaolinite Clay Treated with Sulphuric Acid for Enzyme Immobilization

2013 ◽  
Vol 832 ◽  
pp. 589-595 ◽  
Author(s):  
N.A. Edama ◽  
A. Sulaiman ◽  
K.H. Ku Hamid ◽  
M.N. Muhd Rodhi ◽  
Mohibah Musa ◽  
...  
Keyword(s):  
Surface Area ◽  
Sulphuric Acid ◽  
Enzyme Immobilization ◽  
Morphological Changes ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
Kaolinite Clay ◽  
X Ray ◽  
Mineral Oxides ◽  
Physico Chemical

This study analyzed the effects of sulphuric acid (H2SO4) treatment on pysico-chemical properties and morphological changes of clay obtained from Sg. Sayong, Perak. The clay was ground and sieved to <150μm and treated with different concentrations of H2SO4. The treatment was completed by refluxing the clay with different concentration of H2SO4 (1M, 5M and 10M ) at 100 °C for 4 hours and followed by calcination at 500 °C for 1 hour. The physic-chemical properties and morphological changes of the untreated and treated clay were compared using Surface Area Analyser, X-Ray Diffraction (XRD), Field Emission Scanning Electron Micrograph (FESEM), X-Ray Diffraction (XRD) and Fourier Transformed Infrared Spectroscopy (FTIR). The results showed that acid treatment of 5M increased the surface area from 25 m2/g to 75 m2/g and the pore volume increased from 0.1518 cc/g to 0.3546 cc/g. The nanopore size of the clay decreased from 24.8 nm to 19.4 nm after treated with acid. This can be explained due to the elimination of the exchangeable cations and generation of microporosity. The results of XRF showed SiO2 increased from 58.34% to 74.52% and Al2O3 reduced from 34.6% to 18.31%. The mineral oxides such as Fe2O3, MgO, CaO, K2O and TiO2 also reduced. This concluded that H2SO4 treatment has led to significant removal of octahedral Al3+, Fe3+ cations and other impurities. In conclusion, this study showed the physico-chemical properties and morphology of Sayong clay were improved once treated with H2SO4 and therefore suggests better supporting material for enzyme immobilization.

Facile Synthesis of Nanoporous Carbons with High Surface Area and Their CO2 Adsorption Properties

2015 ◽  
Vol 44 (7) ◽  
pp. 1004-1006
Author(s):  
Takahito Mitome ◽  
Yoshiaki Uchida ◽  
Norikazu Nishiyama
Keyword(s):  
Surface Area ◽  
Co2 Adsorption ◽  
High Surface ◽  
High Surface Area ◽  
Adsorption Properties ◽  
Facile Synthesis ◽  
Nanoporous Carbons

scholarly journals Oxidized BPL Carbons

1993 ◽  
Vol 10 (1-4) ◽  
pp. 75-84 ◽  
Author(s):  
S.S. Barton ◽  
M.J.B. Evans ◽  
J.A.F. Macdonald
Keyword(s):  
Nitric Acid ◽  
Surface Area ◽  
Water Adsorption ◽  
Adsorption Properties ◽  
Bet Surface Area ◽  
Adsorption Sites ◽  
A Value ◽  
Nitrogen Desorption ◽  
Oxidized Carbon ◽  
Increasing Temperature

A series of oxidized carbons has been prepared by treatment of the carbon with concentrated nitric acid at various temperatures, and the surface and adsorption properties of the prepared carbons studied. Water adsorption was modelled using a recently derived equation capable of predicting a value for the primary adsorption sites on the surface of a microporous carbon while fitting the experimentally determined isotherm at high relative pressures. The concentration of primary sites was seen to increase with increasing temperature of oxidation. The very highly oxidized carbon samples were found to have a significantly lower BET surface area determined from nitrogen desorption at 77 K and higher apparent density measured from mercury displacement.

Morphology dependent adsorption of methylene blue on trititanate nanoplates and nanotubes prepared by the hydrothermal treatment of TiO2

2016 ◽  
Vol 75 (2) ◽  
pp. 350-357
Author(s):  
Graham Dawson ◽  
Wei Chen ◽  
Luhua Lu ◽  
Kai Dai
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Pore Volume ◽  
Hydrothermal Reaction ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
High Capacity ◽  
Adsorption Properties

The adsorption properties of two nanomorphologies of trititanate, nanotubes (TiNT) and plates (TiNP), prepared by the hydrothermal reaction of concentrated NaOH with different phases of TiO2, were examined. It was found that the capacity for both morphologies towards methylene blue (MB), an ideal pollutant, was extremely high, with the TiNP having a capacity of 130 mg/g, higher than the TiNT, whose capacity was 120 mg/g at 10 mg/L MB concentration. At capacity, the well-dispersed powders deposit on the floor of the reaction vessel. The two morphologies had very different structural and adsorption properties. TiNT with high surface area and pore volume exhibited exothermic monolayer adsorption of MB. TiNP with low surface area and pore volume yielded a higher adsorption capacity through endothermic multilayer adsorption governed by pore diffusion. TiNP exhibited a higher negative surface charge of −23 mV, compared to −12 mV for TiNT. The adsorption process appears to be an electrostatic interaction, with the cationic dye attracted more strongly to the nanoplates, resulting in a higher adsorption capacity and different adsorption modes. We believe this simple, low cost production of high capacity nanostructured adsorbent material has potential uses in wastewater treatment.

scholarly journals ADSORPTION PROPERTIES OF TITANIA-SILICA MEMBRANES OBTAINED ON CERAMIC SUBSTRАTE

2018 ◽  
Vol 54 (3) ◽  
pp. 274-280
Author(s):  
T. F. Kouznetsova ◽  
A. I. Ivanets ◽  
J. D. Sauka
Keyword(s):  
Surface Area ◽  
Quartz Substrate ◽  
Cetylpyridinium Chloride ◽  
Nitrogen Adsorption ◽  
Mesoporous Structure ◽  
Adsorption Properties ◽  
Molar Ratio ◽  
Silica Membranes ◽  
Metal Silicate ◽  
Adsorption Desorption

Titania-silica membranes on a porous quartz substrate are prepared by its direct contact with metal silicate sol at various Ti/Si ratios in the conditions of coagel sedimentation and presence of cetylpyridinium chloride. The study of textural and adsorption properties of membranes is conducted by low-temperature nitrogen adsorption-desorption, including methods of t-plots and DFT theory. It was shown that obtained membranes have mesoporous structure with the specific surface area and pore hydraulic diameter varied in intervals of 64–217 m2 /g and 4–11 nm, respectively. Developed values of surface area remain up to molar ratio of Ti/Si = 50/50.

scholarly journals Development of Activated Carbon Using One Step Carbonization and Activation Reaction by Polymer Blend Method

2015 ◽  
Vol 57 ◽  
pp. 156-162 ◽  
Author(s):  
S. Manocha ◽  
Parth Joshi ◽  
Amit Brahmbhatt ◽  
Amiya Banerjee ◽  
Snehasis Sahoo ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Surface Characteristics ◽  
Nitrogen Atmosphere ◽  
Activation Process ◽  
Average Pore ◽  
Activation Temperature ◽  
Optimum Synthesis ◽  
Different Temperatures ◽  
One Step

In the present work, a one step carbon activation process was developed by stabilized poly-blend. It is carbonized in nitrogen atmosphere and activated in steam in one step for known interval of times to enhance the surface area and develop interconnected porosity. The weight-loss behavior during steam activation of stabilized poly-blend at different temperatures, surface area and pore size distribution were studied to identify the optimum synthesis parameters. The results of surface characteristics were compared with those of activated carbon prepared by carbonization and activation in two steps. It was found that activation temperature has profound effect on surface characteristics. As activation temperature was raised from 800 °C to 1150 °C, surface area of activated carbon increased about three times. In addition to surface area, average pore diameter also increases with increasing activation temperature. Thus, activated carbon with high percentage of porosity and surface area can be developed by controlling the activation temperature during activation process.

Surface area, porosity and water adsorption properties of fine volcanic ash particles

2004 ◽  
Vol 67 (2) ◽  
pp. 160-169 ◽  
Author(s):  
Pierre Delmelle ◽  
Fr�d�ric Villi�ras ◽  
Manuel Pelletier
Keyword(s):  
Surface Area ◽  
Volcanic Ash ◽  
Water Adsorption ◽  
Adsorption Properties
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