Adsorption and photocatalytic degradation of methylene blue using high surface area titanate nanotubes (TNT) synthesized via hydrothermal method

2017 ◽  
Vol 19 (6) ◽  
Author(s):  
M. N. Subramaniam ◽  
P. S. Goh ◽  
N. Abdullah ◽  
W. J. Lau ◽  
B. C. Ng ◽  
...  
2016 ◽  
Vol 75 (2) ◽  
pp. 350-357
Author(s):  
Graham Dawson ◽  
Wei Chen ◽  
Luhua Lu ◽  
Kai Dai

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.


Author(s):  
Ali H. Jawad ◽  
Ahmed Saud Abdulhameed ◽  
Noor Nazihah Bahrudin ◽  
Nurul Nadiah Mohd Firdaus Hum ◽  
S. N. Surip ◽  
...  

Abstract In this work, sugarcane bagasse waste (SBW) was used as a lignocellulosic precursor to develop a high surface area activated carbon (AC) by thermal treatment of the SBW impregnated with KOH. This sugarcane bagasse waste activated carbon (SBWAC) was characterized by means of crystallinity, porosity, surface morphology and functional groups availability. The SBWAC exhibited Type I isotherm which corresponds to microporosity with high specific surface area of 709.3 m2/g and 6.6 nm of mean pore diameter. Further application of SBWAC as an adsorbent for methylene blue (MB) dye removal demonstrated that the adsorption process closely followed the pseudo-second order kinetic and Freundlich isotherm models. On the other hand, thermodynamic study revealed the endothermic nature and spontaneity of MB dye adsorption on SBWAC with high acquired adsorption capacity (136.5 mg/g). The MB dye adsorption onto SBWAC possibly involved electrostatic interaction, H-bonding and π-π interaction. This work demonstrates SBW as a potential lignocellulosic precursor to produce high surface area AC that can potentially remove more cationic dyes from the aqueous environment.


2018 ◽  
Vol 35 (6) ◽  
pp. 067501
Author(s):  
Hui-Fang Yang ◽  
Ling-Zhi Tang ◽  
Qiang Sun ◽  
Lei Sun ◽  
Zhen-Hua Li ◽  
...  

2018 ◽  
Vol 94 (4) ◽  
pp. 633-640 ◽  
Author(s):  
Bharath Velaga ◽  
Pradeep P. Shanbogh ◽  
Diptikanta Swain ◽  
Chandrabhas Narayana ◽  
Nalini G. Sundaram

ACS Omega ◽  
2020 ◽  
Vol 5 (23) ◽  
pp. 13548-13556 ◽  
Author(s):  
Junhua Hou ◽  
Yijian Liu ◽  
Shikai Wen ◽  
Weitao Li ◽  
Riquan Liao ◽  
...  

RSC Advances ◽  
2019 ◽  
Vol 9 (42) ◽  
pp. 24368-24376 ◽  
Author(s):  
Ajay Kumar Adepu ◽  
Srinath Goskula ◽  
Suman Chirra ◽  
Suresh Siliveri ◽  
Sripal Reddy Gujjula ◽  
...  

In the present study, we synthesized several high-surface area V2O5/TiO2–SiO2 catalysts (vanado titanium silicate, VTS). The synthesized materials are characterized by PXRD, FE-SEM/EDAX, TEM, BET-surface area, FT-IR, UV-Vis, XPS, fluorescence and photocatalytic studies.


Author(s):  
Nour Bouanimba ◽  
Nassima Laid ◽  
Razika Zouaghi ◽  
Tahar Sehili

Abstract The photocatalytic activities of TiO2 Degussa P25 and Millennium PCs (PC50, PC100, PC105 and PC500) were evaluated by the photocatalytic degradation of Bromothymol Blue (BTB). The relationship between the photocatalytic reaction and the adsorption of BTB on the TiO2 catalysts at acidic, natural and basic mediums of pH was investigated. The crystalline phase, average crystalline size and surface area of the catalyst were found to have a significant influence on the adsorption and photocatalytic activity of the TiO2 samples. The mixed phase of anatase/rutile (Degussa P25) was found to be the most efficient photocatalytical material than pure phase anatase (Millennium PCs) and faster degradation is observed for PC500 compared to other Millennium PCs, this was attributed to the high surface area of PC500. Within the PC50, PC100 and PC105 series, the photocatalytic efficiency increased with the decrease of the surface area. The COD and TOC removals increased slowly, however, the decolorization ratio of BTB increased rapidly at the same time. Thereafter, the efficiency of P25 and PC500 were compared in presence of H2O2, Cl− and HCO3− at different mediums of pH. H2O2 was found to enhance strongly the BTB degradation in presence of P25 with an optimum at natural pH. In contrast, the reaction was inhibited in the presence of PC500, due to the inhibition of dye adsorption. At different pH, the BTB degradation has been significantly inhibited in the presence of the mixtures of HCO3−/H2O2. In contrast, the mixtures of Cl−/H2O2 accelerate the BTB degradation at acidic pH.


2019 ◽  
Vol 5 (1) ◽  
pp. 10 ◽  
Author(s):  
Lok Shrestha ◽  
Mamata Thapa ◽  
Rekha Shrestha ◽  
Subrata Maji ◽  
Raja Pradhananga ◽  
...  

Iodine and methylene blue adsorption properties of the high surface area nanoporous carbon materials derived from agro-waste and rice husk is reported. Rice husk was pre-carbonized at 300 °C in air followed by leaching out the silica nanoparticles by extraction with sodium hydroxide solution. The silica-free rice husk char was mixed with chemical activating agents sodium hydroxide (NaOH), zinc chloride (ZnCl2), and potassium hydroxide (KOH) separately at a mixing ratio of 1:1 (wt%) and carbonized at 900 °C under a constant flow of nitrogen. The prepared carbon materials were characterized by scanning electron microscopy (SEM), Fourier transformed-infrared spectroscopy (FT-IR), powder X-ray diffraction (pXRD), and Raman scattering. Due to the presence of bimodal micro- and mesopore structures, KOH activated samples showed high specific surface area ca. 2342 m2/g and large pore volume ca. 2.94 cm3/g. Oxygenated surface functional groups (hydroxyl, carbonyl, and carboxyl) were commonly observed in all of the samples and were essentially non-crystalline porous particle size of different sizes (<200 μm). Adsorption study revealed that KOH activated samples could be excellent material for the iodine and methylene blue adsorption from aqueous phase. Iodine and methylene blue number were ca. 1726 mg/g and 608 mg/g, respectively. The observed excellent iodine and methylene blue adsorption properties can be attributed to the well-developed micro- and mesopore structure in the carbon material. This study demonstrates that the agricultural waste, rice husk, and derived nanoporous carbon materials would be excellent adsorbent materials in water purifications.


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