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BET theory

About: BET theory is a research topic. Over the lifetime, 9046 publications have been published within this topic receiving 286142 citations.


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Journal ArticleDOI
TL;DR: In this paper, a simple in situ soft chemical synthesis of nanoscale copper(II) oxide, together with its characterization and a study of the adsorption and desorption behaviors of Pb(II), was conducted.
Abstract: The present work deals with a simple in situ soft chemical synthesis of nanoscale copper(II) oxide, together with its characterization and a study of the adsorption and desorption behaviors of Pb(II) on nanoscale CuO. The nanoparticles are characterized by XRD, FESEM, TEM and BET surface area analyses. Electron microscopy clearly reveals a rod-like morphology of rhombohedral CuO, with an average diameter of ∼5 nm and a length extending up to 50 nm. BET shows the average surface area of the nanorods to be ∼52.57 m2 g−1. In an adsorption study, the influence of operational conditions, such as the contact time, the initial concentration of Pb(II), the initial pH of the solution and the temperature, on the adsorption of Pb(II) has also been examined. Studies also reveal that the uptake of Pb(II) onto CuO is a fast process; >70% of the uptake occurred within the first 10 min of contact time and uptake reached >92% within 60 min. The maximum sorption capacity of Pb(II) is 3.31 mg g−1 at 298 K. The +ve ΔS° value and the +ve ΔH° value of 37.77 kJ mol−1 indicate the endothermic nature of the adsorption process, whereas a decrease of Gibbs free energy (ΔG°) with increasing temperature indicates the spontaneous nature of the adsorption process. The adsorbent can be up to 84.1% regenerated using dilute acid and shows potential for the removal of lead from contaminated water.

152 citations

Journal ArticleDOI
TL;DR: The batch and column kinetics of methylene blue and red basic 22 adsorption on mild acid-hydrolysed beech sawdust were investigated to explore its potential use as a low cost adsorbent for wastewater dye removal.

152 citations

Journal ArticleDOI
TL;DR: Porous anatase TiO2 has shown moderate porosity with a BET surface area of 220 m2 g−1 attributed to the highly porous structure of the MIL-125(Ti) precursor.
Abstract: Porous anatase TiO2 has been prepared, for the first time, through the calcination of a metal–organic framework (MOF) precursor under an air atmosphere at 380 °C. The resulting TiO2 has shown moderate porosity with a BET surface area of 220 m2 g−1 attributed to the highly porous structure of the MIL-125(Ti) precursor. The porous anatase TiO2 was examined as a lithium-ion battery anode, exhibiting high capacity retention and good rate capability. The porous structure of anatase TiO2 enforces Li+ diffusion and helps to buffer the volumetric variation. It has shown reversible capacities of 166, 106 and 71 mA h g−1 at 1 C, 5 C and 10 C charge/discharge rates, respectively, after 500 cycles.

152 citations

Journal ArticleDOI
TL;DR: Electrochemical analysis and structural characterizations predict that the active sites for the ORR are most likely to be the in situ generated N-FeN(2+2)/C moieties, which are distributed along the carbon framework.
Abstract: The facile synthesis of a porous carbon material that is doped with iron-coordinated nitrogen active sites (FeNC-70) is demonstrated by following an inexpensive synthetic pathway with a zeolitic imidazolate framework (ZIF-70) as a template. To emphasize the possibility of tuning the porosity and surface area of the resulting carbon materials based on the structure of the parent ZIF, two other ZIFs, that is, ZIF-68 and ZIF-69, are also synthesized. The resulting active carbon material that is derived from ZIF-70, that is, FeNC-70, exhibits the highest BET surface area of 262 m(2) g(-1) compared to the active carbon materials that are derived from ZIF-68 and ZIF-69. The HR-TEM images of FeNC-70 show that the carbon particles have a bimodal structure that is composed of a spherical macroscopic pore (about 200 nm) and a mesoporous shell. X-ray photoelectron spectroscopy (XPS) reveals the presence of Fe-N-C moieties, which are the primary active sites for the oxygen-reduction reaction (ORR). Quantitative estimation by using EDAX analysis reveals a nitrogen content of 14.5 wt.%, along with trace amounts of iron (0.1 wt.%), in the active FeNC-70 catalyst. This active porous carbon material, which is enriched with Fe-N-C moieties, reduces the oxygen molecule with an onset potential at 0.80 V versus NHE through a pathway that involves 3.3-3.8 e(-) under acidic conditions, which is much closer to the favored 4 e(-) pathway for the ORR. The onset potential of FeNC-70 is significantly higher than those of its counterparts (FeNC-68 and FeNC-69) and of other reported systems. The FeNC-based systems also exhibit much-higher tolerance towards MeOH oxidation and electrochemical stability during an accelerated durability test (ADT). Electrochemical analysis and structural characterizations predict that the active sites for the ORR are most likely to be the in situ generated N-FeN(2+2)/C moieties, which are distributed along the carbon framework.

151 citations

Journal ArticleDOI
TL;DR: A metal organic framework modified with amino group (NH2-UiO-66) was functionalized with glycidyl methacrylate (GMA) via ring opening reaction between the amine species in the framework and epoxy groups in GMA as discussed by the authors.

151 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023166
2022356
2021525
2020551
2019533
2018531