Synthesis of MOF@clay composites photocatalysts for environmental remediation

2017 Fiscal Year Annual Research Report

• Project/Area Number: 17F17355
• Research Institution: Kyushu University
• Principal Investigator: 笹木 圭子 九州大学, 工学研究院, 教授 (30311525)
• Co-Investigator(Kenkyū-buntansha): PAWAR RADHESHYAM 九州大学, 工学(系)研究科(研究院), 外国人特別研究員
• Project Period (FY): 2017-11-10 – 2020-03-31
• Keywords: Adsorption / Metal organic framework / Eutrophication / Phosphate

Outline of Annual Research Achievements

It is impervious to exploit new progressive materials containing abundant binding sites and high affinity to achieve highly efficient and specific capture of phosphate to control eutrophication. In this regards herein, water stable Lanthanum and fumaric acid-based metal-organic frameworks (La-fumarate MOFs) have been successfully synthesized based on a simple solvothermal method for effective phosphate remediation.
The main objective of the research work as mentioned below: 1) The synthesis of La-Fum MOF is synthesized in a DMF based solvothermal system, 2) The water and NaOH based hydrothermal synthesis of the La-fumarate MOFs in presence or absence of acetic acid as a modulator, 3) Systematic characterization of resultant La-Fum MOF materials, 4) Evaluation of phosphate adsorption behavior of developed La-Fum@MOFs materials by the influence of several batch adsorption experiments such as La content, contact time, a concentration of phosphate, pH of the medium and presence of coexisting anions and others, 5) The investigation of phosphate sorption mechanism through physiochemical analyses.
The particle size of the resulting La-fumarate MOFs was effectively influenced by the amount of acetic acid as a modulator. Uptake capacity of phosphate on La-fumarate MOFs demonstrated 4 mmol/g. This might be attributed due to the ligand exchange with -OH groups coordinated to La in La-fumarate MOF. We believe that the developed La-fum MOF materials can reduce phosphate to below the permitted level (0.1 mg/L) which can be applied to mitigate the increasingly eutrophic problems.

Current Status of Research Progress

3: Progress in research has been slightly delayed.

Reason

La-Fum MOF was successfully synthesized using a modulator and investigated for adsorption of phosphate though ligand exchange. But MOF@clay composites have not yet been synthesized, and the photocatalytic properties of MOFs have not yet been approached, which is the main objectives in the present work.Several clay minerals are selected to maintain the band gap. It is an interesting approach by using natural clay for funtional environmental materials.

Strategy for Future Research Activity

Metal Organic Frameworks (MOFs) have attracted extensive attention due to their large surface area, diverse structures, and tunable functionality. However, poor hydrostability of the most reported MOFs hinder their practical application severely. Looking to this issue our future approach is to modulate the properties of unstable MOFs material by hybridizing with natural/synthetic clay materials to develop stable MOF@clay composite. In this regards, we are planning for the below-mentioned work.1)Improving the hydro stability and photocatalytic performance of Zn/Cu/Ti bases metal-organic frameworks by hybridizing with montmorillonite/attapulgite/hectorite, clay materials. In addition, it's well-known that Integration of ultra-small MOF nanocrystals with a smart functional scaffold, which could disperse well at the nanoscopic level would enlarge the scope of the composites in several applications. In this regards, we are planning for the below-mentioned work.2) Amino-functionalized clay for adsorption of heavy metal ions from aqueous solutions and metal adsorbed amino clay for synthesis of aminoclay@MOF composite.3) MOF-aminoclay composites for adsorption and photocatalytic degradation of rhodamine dyes.4) Facile synthesis of MgAl-layered double hydroxide supported metal-organic framework nanocomposite for cationic and anionic radionuclides.