The ZIF-8 material was directly modified by iron (Fe(II)) with The modification direct of ZIF-8 by Fe with the intial molar ratios Fe(II)/(Fe(II)+Zn(II)) limit reached 30%.. Then the l[r]
Trang 1SOCIALIST REPUBLIC OF VIETNAM Independence – Freedom – Happiness
THESIS COMPENDIUM
Full name of student research: MAI THI THANH
Title of thesis: “Study on modification of ZIF-8 material and its applications”
Major: Physical chemistry and Theoretical chemistry Code: 62.44.01.19
2 Prof.Dr Nguyen Phi Hung
Training institutions: College of Science – University of Hue
1 PURPOSE AND RESEARCH SUBJECTS
1.1 Research purposes
Synthesis and iron, nickel doped zeolite imidazolate framework-8 (Fe-ZIF-8, Ni-ZIF-8) This materials have hight photocatalytic and adsorption activation Using ZIF-8 in modified electrode and Ni-ZIF-8 in synthesis of NiO-ZnO semiconductor nanoparticles
1.2 Research subjects
ZIF-8 material
These dyes: Remazol Deep black RGB (RDB), Astrazon black AFDL,
Dianix black, Fuchsin basic, Blue methylene
2 RESEARCH METHODS USED
2.1 Determining the structural characteristics of materials methods: XRD,
FT-IR, TG-DTA, SEM, TEM, XPS, BET, DR-UV-Vis, DLS
2.2 Qualitative, quantitative analysis methods: UV-Vis, AAS
2.3 Another methods: Statistic
Trang 23 MAJOR RESULTS AND CONCLUSIONS
3.1 Synthesis ZIF-8 from Zn(II) and 2-methyl imidazole in methanol solvent at room temperature The properties of ZIF-8 was hight surface area of 1484 m2/g, stable in ambient condition for a year, in water at least for 14 days, in water and organic solvents for
8 hours at boiling conditions and in the pH range 2,7 to 12,0
3.2 The ZIF-8 was used as an modyfied electrode (BiF/Naf/ZIF-8/GCE) for the determination of Pb(II) by ASV The characteristicof electrochemical process on electrode surface, such as: participation of the one proton and two electrons, the electrons transfer coefficient α = 0.458 and the electron transfer rate constant Ks = 248.3 s-1
The lead oxidation process was irreversible Under the optimal conditions, the peak current of Pb(II) was linearly proportional to its concentration over the range 12 to 100 ppb The limit of detection and the limit of quantitation were 4.16 ppb and 12.5 ppb, respectively The ensitivity was 0.290 μA/ppb For our knowledge, this is the first time, ZIF-8 has been known as a potential electrode modifier for lead determination in aqueous solution by DP-ASV
3.3 The ZIF-8 material was directly modified by iron (Fe(II)) with The modification direct of ZIF-8 by Fe with the intial molar ratios Fe(II)/(Fe(II)+Zn(II)) limit reached 30% Then the low molar rate of Fe(II), a part of Zn(II) of crystals are isomorphous replaced by Fe(II) and Fe-ZIF-8 was hight surface area However, at the hight molar rate, Fe(II) and Fe(III) were either isomorphous replace or distribute in porous of the material The ZIF-8 and Fe-ZIF-8 have hight CO2 and CH4 adsoption activation Adsoption capacity of CO2 onto are higher than that of CH4 The adsoption capacity of gas onto ZIF-8 is much higher than that onto Fe-ZIF-8 The adsoption capacity of gas decreased with an increase in iron amount incorporated
3.4 The ZIF-8 and Fe-ZIF-8 were used for the removal of Remadazol deep black RGB (RDB) from aqueous solutions Natarajan - Khalaf equation and recovery method were combined to reseach reversible adsorption kinetics onto the ZIF-8 and Fe-ZIF-8 materials The RDB adsorption onto ZIF-8 and Fe-ZIF-8 involved a phylsical - chemcal mechanism The diffusion of RDB into these materials was essentially film-diffusion and best fit with two segments linear regression of Weber's model The introduction of iron into ZIF-8 provided a much lager adsorption catacity and faster adsorption kinetic of RDB than ZIF-8 The adsorption activity due to the electrostatic interaction and the hydrophobic and π−π interaction between the aromatic rings of the RDB dye and the aromatic imidazole
Trang 3rings of the adsorbent for ZIF-8, the coordination of the nitrogen atoms and oxygen in carboxyl group in RDB molecules to the Fe(II) in ZIF-8 framework The ZIF-8 and Fe-ZIF-8 were reusability by NaOH 0.001M The adsorption capacity was seem unchangeable and structure were not broken after three cycles
3.5 The study on photocatalytic activity of ZIF-8 and Fe-ZIF-8 in degradation RDB dye under sunlight The iron doped ZIF-8 brought a red shift and drove the band gap in visible light The Fe-ZIF-8 can act as a sun-light-driven photocatalyst for highly efficient degradation of RDB dye Fe-ZIF-8 material was stable in photocatalyst condition The photocatalytic activity and structure of Fe-ZIF-8 were not broken after three cycles
3.6 The p-NiO/n-ZnO nanocparticles with 10-15 nm level were synthesised from Ni-ZIF-8 and were hight photocatalytic activity under sunlight The p-NiO/n-ZnO material
had paramagnetism and hight photocatalytic degradation of RDB dye, Fuchsin basic and
methylene blue under sunlight For our knowledge, this is the first report about
p-NiO/n-ZnO nanocparticles were prepared by the thermal treatment of Ni-ZIF-8
Hue, September 05, 2017
Instructor Student research
Prof.Dr Dinh Quang Khieu Mai Thi Thanh