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- PublicationOpen AccessSynergistic effect of nitrogen and molybdenum on activated carbon matrix for selective adsorptive Desulfurization: Insights into surface chemistry modification(2022-01) Azeez, Musa O.; Tanimu, Abdulkadir; Alhooshani, Khalid; Ganiyu, Saheed A.This study reports the synthesis of mesoporous metal-modified nitrogen doped activated carbon (AC-N-Mo) from date seeds by ZnCl2 activation and its applicability for selective adsorptive desulfurization of dibenzothiophene (DBT). The AC-N-Mo exhibits higher adsorption capacity for DBT at 100 mg-S/L with the maximum removal percentage of 99.7 % corresponding to 19.94 mg-S/g at room temperature than the unmodified carbon with 17.96 mg-S/g despite its highest surface area and pore volume of 1027 m2g−1 and 0.55 cm3g−1 respectively. The adsorption capacity breakthrough follows the order AC-N-Mo > AC-Mo > AC > AC-N. Also, AC-N-Mo displays excellent selectivity in the presence of aromatics (toluene, naphthalene, and 1-methylisoquinoline). The enhancement in the DBT uptake capacities of AC-N-Mo is attributed to the synergistic effect of nitrogen heteroatom that aids the dispersion of molybdenum nanoparticles on carbon surface thereby improving its surface chemistry and promising textural characteristics. The kinetic studies showed that the DBT adsorption proceeds via pseudo-second order kinetics while the isotherm revealed that Langmuir fit the data more accurately for the adsorbents. The physical properties (surface area, pore volume, particle size, etc.) and chemical properties (carbon content, etc.) of as-prepared adsorbents namely; AC, AC-N, AC-N-Mo, and AC-Mo were characterized by N2– physisorption, X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Spectroscopy/Energy Dispersive Spectroscopy (SEM/EDS), Raman Spectroscopy (RS), Fourier Transform Infrared Spectroscopy (FTIR) and Ammonia-Temperature-Programmed Desorption (NH3-TPD).
- PublicationOpen AccessDesign, synthesis and application of a sponge-like nanocomposite ceramic for the treatment of Ni(II) and Co(II) wastewater in the zinc ingot industry(2022-01) Abdollahi, Sayed Asaad; Mokhtariyan, Nader; Ameri, ElhamIn this study, a sponge-like nanocomposite ceramic was made of clay, bovine bone nano-powder, and human hair; to remove Ni(II) and Co(II) ions from synthetic and industrial wastewaters. The structure of sponge-like nanocomposite ceramic was investigated with XRD (Hexagonal structural type of hydroxyapatite) and functional groups were identified using FT-IR (Hydroxyl @ 3573 cm-1 and Phosphate @ 1045 cm-1). The specific surface and morphology of the ceramic-based on BET (172.46 m2g-1) and FE-SEM (Nano-hydroxyapatite: 100 nm), respectively showed that the use of human hair creates good porosity. The process was optimized at pH 6, temperature 40 ℃, adsorbent mass 17 g, initial concentration iofns 233 mg L−1, and retention time 178 min. Kinetic models, thermodynamic parameters and, isotherm models were applied to describe the adsorption equilibrium data. The Ni(II) and Co(II) adsorption efficiency, from industrial wastewaters, were more than 95%. The adsorbents could be regenerated and reused for up to 60 consecutive cycles.
- PublicationOpen AccessSynthesis of mesoporous TiO2/BMMs via hydrothermal method and its potential application toward adsorption and photocatalytic degradation of crystal violet from aqueous solution(2022-01) Gul, Anadil; Ullah, Raza; Sun, Jihong; Munir, Tallat; Bai, ShiyangThe novel mesoporous TiO2/BMMs nanocomposites using bimodal mesoporous silica (BMMs) as support and rutile-anatase mixed phase as active species were successfully synthesized via hydrothermal and subsequent calcination method. Their structural and physiochemical properties were characterized by X-ray diffraction, scanning/transmission electron microscopy, BET-isotherms, inductive coupled plasma optical emission spectroscopy, zeta potential, Fourier transform infrared and UV–visible spectroscopy. The results demonstrated that the photocatalytic degradation activity of the synthesized catalysts were extensively enhanced as compare to bare TiO2, due to the highly uniform dispersion of mixed phases (Anatase and Rutile) TiO2 on the bimodal mesoporous surfaces. Particularly, the catalytic efficiency became increased as increasing the calcination temperature, showing the highest (98%) overall removal of CV dye using TBH5d as catalyst calcinated at 800 °C. Its most interesting finding is that the % adsorption of TBH5d was 46 %, more than that (26%) of TBH5c calcinated at 600 ℃, however, its % degradation was 21 %, lower than that (39 %) of TBH5c for dye concentration of 20 ppm in 50 min. Meanwhile, the kinetic adsorption and degradation performances were followed the pseudo second and first order models, respectively, further proving the high degradation efficiency of TBH5c with high rate constant than that of TBH5d. Thermodynamic parameters (ΔGads, ΔHads, and ΔSads) were calculated, suggesting the spontaneous and exothermic procedure with high entropy, while the adsorption equilibrium data was fitted to Dubinin-Radushkevich model. Both TBH5c and TBH5d showed an excellent stability and reactivity 71.2 and 61 %, respectively, even after 5th cycles. Thus, these results suggested that that TBH5c may be one of the suitable candidates in wastewater treatments.
- PublicationOpen AccessFacile synthesis of Z-scheme NiO/α-MoO3 p-n heterojunction for improved photocatalytic activity towards degradation of methylene blue(2022-01) Li, Jintao; Liu, Hongjie; Liu, Zhuo; Yang, Daiqiong; Zhang, Mengzhao; Gao, Luning; Zhou, Yahong; Lu, ChangyuIn this article, Z-scheme NiO/α-MoO3 p-n heterojunction is successfully synthesized by a facile hydrothermal route. The phase and nanostructures are researched through a series of characterizations, such as XRD, SEM, TEM, EDX, XPS and DRS. It is confirmed that the NiO nanoparticles are deposited homogeneously on one dimensional α-MoO3 nanobelts and p-n heterojuction is constructed at the interface of α-MoO3 and NiO. Photocatalytic activity of the as-synthesized photocatalysts is investigated by photodegradation of methylene blue (MB) under simulated solar light irradiation. Compared with bare α-MoO3, the NiO/α-MoO3 p-n heterojunction exhibits significantly improved photocatalytic activity and photostability for MB degradation. The improvement in the photocatalytic performance can be attributed to the optimization of the charge transport pathway offered by Z-scheme heterojunctions, which can promote the effective separation of electron-hole pairs. The results indicate that Z-scheme NiO/α-MoO3 p-n heterojunction is a novel and efficient photocatalyst with potential application for the removal of organic contaminant in wastewater.