Assessment of Fe-Based Organic Framework (Fe-MOF) as Nutrient-Slow-Releasing Material

Abstract

There has been serious focus about improving the efficiency of fertilizers so as to substantially ease the problem of food security, deficit of trace elements, soil degradation, groundwater, and air pollution. Hence, assessment of Fe-Based Organic Framework (Fe-MOF) as Nutrient-Slow-Releasing Material (slow-releasing fertilizer); synthesized hydrothermally from ferric chloride, dipotassium hydrogen phosphate, diammonium hydrogen phosphate, urea, and oxalic acid (OXA) is herein studied. From the FTIR results, -OH & C=O (OXA) and NH2 (urea) participated in the structural formation of the MOFs. Crystals of the Fe-MOFs at different magnifications with pores sizes of ~1.10 μm were observed from the SEM results. The major peaks are (110) and (111) corresponding to 2𝜃 at 28° and 31°, respectively, as given in MOF1. For MOF2 the peaks of (110), (111), and (121) correspond to 2𝜃 at 22.12°, 27.15°, and 33°, respectively. These indicate that the metal-carbonyl linkage for the MOF. These results agreed with the face and body centered crystals. In the results of nutrient-slow-releasing capability of the iron-MOF, the trend of the release at the end of the 3-week is: PO43- (2.75 mg/L) < Fe3+ (3.30 mg/L) < NH4+ (3.36 mg/L) < K+ (406 mg/L) for MOF1 and PO43- (2.75 mg/L) < Fe3+ (3.30 mg/L) < NH4+ (3.36 mg/L) for MOF2. Therefore, the synthesized MOF is recommended for real-life tests as slow-releasing fertilizer. The use of such products would also ensure food security, soil sustainability, and lessen pollution against the fast-releasing fertilizers. More so, the synthesis is handy and utilizes inexpensive reagents.