Papers by Akiode Olubunmi Kolawole
Methodical study of chromium (VI) ion adsorption from aqueous solution using low-cost agro-waste material: isotherm, kinetic, and thermodynamic studies
Environmental Science and Pollution Research
This study involved preparation and modification of Saccharum officinarium as adsorbent used for ... more This study involved preparation and modification of Saccharum officinarium as adsorbent used for the removal of chromium (VI) ions in a batch process. The adsorbent was modified with oxalic acid for improved performance of the adsorbent by increasing the surface area of the adsorbent. Surface morphology of the adsorbents was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), while Fourier transform infrared (FT-IR) analysis was carried out before and after the adsorption of Cr (VI) ions to determine the participating functional group in the processes. The optimum adsorption was attained at pH 2 and contact time of 180 min with efficiency of adsorption of 56.7 and 92.6% onto RSO and MSO, respectively. The adsorption capacity increases with increase in initial metal ion concentration of the sorption mixture. The isotherms studies indicate that the experimental data were best fitted to Freundlich, Langmuir, and Sips models with R 2 = 0.999 for adsorption of Cr (VI) ions onto raw S. officinarium (RSO) and modified S. officinarium (MSO). The maximum adsorption capacity obtained were 227.27 and 243.90 mg*g-1 while the adsorption energy obtained from D-R were found to be 3.460 and 6.325 kJ*mol-1 onto RSO and MSO, respectively. This revealed that the physiosorption process was favored in interaction of Cr (VI) ions onto both adsorbents. Separation factors obtained showed that the process is favored with increase in initial concentration of the adsorbate. Thermodynamic parameter values obtained showed that the sorption of Cr (VI) ions onto RSO and MSO is feasible, spontaneous, and endothermic in nature. The positive value of ΔS° indicates increase in disorderliness of the adsorption process. Kinetic data achieved at different initial concentrations of adsorbate have been analyzed, and the mechanism of the reaction was also studied by intra-particle and Bangham kinetic model. Each of the models was tested with R 2 ˃ 0.9, where pseudo-second-order is the best-fitted model and Bangham mechanism only fitted with adsorption of Cr (VI) ions onto RSO. The reusability potential of RSO and MSO contributes to the economic values and reliability of the adsorbents for removal of Cr (VI) ions from aqueous solution.
Environmental Science and Pollution Research, 2023
This study involved preparation and modification of Saccharum officinarium as adsorbent used for ... more This study involved preparation and modification of Saccharum officinarium as adsorbent used for the removal of chromium (VI) ions in a batch process. The adsorbent was modified with oxalic acid for improved performance of the adsorbent by increasing the surface area of the adsorbent. Surface morphology of the adsorbents was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), while Fourier transform infrared (FT-IR) analysis was carried out before and after the adsorption of Cr (VI) ions to determine the participating functional group in the processes. The optimum adsorption was attained at pH 2 and contact time of 180 min with efficiency of adsorption of 56.7 and 92.6% onto RSO and MSO, respectively. The adsorption capacity increases with increase in initial metal ion concentration of the sorption mixture. The isotherms studies indicate that the experimental data were best fitted to Freundlich, Langmuir, and Sips models with R 2 = 0.999 for adsorption of Cr (VI) ions onto raw S. officinarium (RSO) and modified S. officinarium (MSO). The maximum adsorption capacity obtained were 227.27 and 243.90 mg*g-1 while the adsorption energy obtained from D-R were found to be 3.460 and 6.325 kJ*mol-1 onto RSO and MSO, respectively. This revealed that the physiosorption process was favored in interaction of Cr (VI) ions onto both adsorbents. Separation factors obtained showed that the process is favored with increase in initial concentration of the adsorbate. Thermodynamic parameter values obtained showed that the sorption of Cr (VI) ions onto RSO and MSO is feasible, spontaneous, and endothermic in nature. The positive value of ΔS° indicates increase in disorderliness of the adsorption process. Kinetic data achieved at different initial concentrations of adsorbate have been analyzed, and the mechanism of the reaction was also studied by intra-particle and Bangham kinetic model. Each of the models was tested with R 2 ˃ 0.9, where pseudo-second-order is the best-fitted model and Bangham mechanism only fitted with adsorption of Cr (VI) ions onto RSO. The reusability potential of RSO and MSO contributes to the economic values and reliability of the adsorbents for removal of Cr (VI) ions from aqueous solution.
This study involved preparation and modification of Saccharum officinarium as adsorbent used for ... more This study involved preparation and modification of Saccharum officinarium as adsorbent used for the removal of chromium (VI) ions in a batch process. The adsorbent was modified with oxalic acid for improved performance of the adsorbent by increasing the surface area of the adsorbent. Surface morphology of the adsorbents was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), while Fourier transform infrared (FT-IR) analysis was carried out before and after the adsorption of Cr (VI) ions to determine the participating functional group in the processes. The optimum adsorption was attained at pH 2 and contact time of 180 min with efficiency of adsorption of 56.7 and 92.6% onto RSO and MSO, respectively. The adsorption capacity increases with increase in initial metal ion concentration of the sorption mixture. The isotherms studies indicate that the experimental data were best fitted to Freundlich, Langmuir, and Sips models with R 2 = 0.999 for adsorption of Cr (VI) ions onto raw S. officinarium (RSO) and modified S. officinarium (MSO). The maximum adsorption capacity obtained were 227.27 and 243.90 mg*g -1 while the adsorption energy obtained from D-R were found to be 3.460 and 6.325 kJ*mol -1 onto RSO and MSO, respectively. This revealed that the physiosorption process was favored in interaction of Cr (VI) ions onto both adsorbents. Separation factors obtained showed that the process is favored with increase in initial concentration of the adsorbate. Thermodynamic parameter values obtained showed that the sorption of Cr (VI) ions onto RSO and MSO is feasible, spontaneous, and endothermic in nature. The positive value of ΔS° indicates increase in disorderliness of the adsorption process. Kinetic data achieved at different initial concentrations of adsorbate have been analyzed, and the mechanism of the reaction was also studied by intra-particle and Bangham kinetic model. Each of the models was tested with R 2 ˃ 0.9, where pseudo-second-order is the best-fitted model and Bangham mechanism only fitted with adsorption of Cr (VI) ions onto RSO. The reusability potential of RSO and MSO contributes to the economic values and reliability of the adsorbents for removal of Cr (VI) ions from aqueous solution.
Materials Today Communications, 2020
Metal oxides have been reported as high capacity anode materials in Lithium-ion batteries (LIBs) ... more Metal oxides have been reported as high capacity anode materials in Lithium-ion batteries (LIBs) but lack merit of commercialization due to volume-expansion during operation and poor electronic conductivity. Nanosized metal oxide could be used to circumvent these demerits. In this work, we examined the application of tin oxide nanoclusters (Sn 3 O z , z = 0, 3-7) as anode materials in LIB using ab initio density functional theory perspective. Analysis of moderately lithiated tin oxide nanoclusters (Li x Sn 3 O z , x = 1-10) indicates a tremendous reduction in volume-expansion due to high surface area of the nanoclusters by analysis of change in Sn-Li bond length with number of lithiation by process of alloying. Structural analysis also revealed the formation of Li 2 O by conversion reaction during lithiation. Stability studies by binding energy (B.E.) during lithiation showed decreased stability as lithiation increased. The role of chemical reactivity concept on the lithiation of Sn 3 O z nanoclusters were revealed by the physicochemical properties of the nanoclusters. Electrophilicity studies reveals the capability of the nanoclusters to accept electrons from the inserted Li. Sn 3 and Sn 3 O 3 nanoclusters were the most suitable anode materials amongst other nanoclusters presented with average intercalation voltage (AIV) of 0.67 and 1.12 V respectively. The adsorption energy (E ads) and dissociation energy (E dis) obtained showed that Li dimer formation can be prevented by these nanoclusters as anode. The calculations substantiate the suitability of tin oxide nanoclusters as anode material in LIBs.
Journal of Nanoparticle Research, 2020
A systematic conceptual study of the properties of tin oxide nanoclusters Sn n O m (n = 1-6; 2n+1... more A systematic conceptual study of the properties of tin oxide nanoclusters Sn n O m (n = 1-6; 2n+1 ≤ m ≤ 4n+2) with ozonide ion or mixed ozonide with molecular O 2 0 , oxide (O 2-), peroxide (O-) or superoxide (O 2-) was investigated using the ab initio density functional theory perspective. Bader charge calculations revealed the oxidation state of Sn and established formation of terminal oxide moiety in the nanoclusters. The stability investigation was carried out by calculations of the binding energy (BE) per atom, the second difference total energy (Δ 2 E(m)) and the gap between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) while adsorption energy per O 2 and O 3 was investigated. Exploring the variation of the reactivity parameters and reaction energy with sizes revealed size dependence on physicochemical properties of the nanoclusters. Magnetism studies show the contribution of O 2 , O-, O 2-and O 3 to the magnetic moment of the nanoclusters.
American Chemical Science Journal, 2015
The generation of electronic waste (e and electronic industries. E-waste is term used to describe... more The generation of electronic waste (e and electronic industries. E-waste is term used to describe unwanted electronic products. E contained toxic heavy metals such as barium, cadmium, chromium, copper, arsenic, zinc, nickel and lead. This study evaluated the discharge of heavy metals from e
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Papers by Akiode Olubunmi Kolawole