Performance and Evaluation of Slow-Release Fertilizer Encapsulated by Waterless Synthesized GO Sheets

Slow-release fertilizer was developed by encapsulating NPK compound pellets with graphene oxide (GO) sheets employing a waterless synthesis technique. As-prepared GO sheets were characterized by XRD, Raman, XPS, FTIR, SEM, and EDS. The XRD patterns of the GO sheets indicate that the peak for the GO is observed at 2θ = 9.3°, and the peak (002) for graphite vanished. Moreover, a higher intensity ratio of the Raman ID/IG of the GO sheets than that of pristine graphite confirms the oxidation of the graphite. The FTIR and XPS analyses provided information on electronic structure, chemical structure, and oxygen-bonding neighbors. The SEM images indicated the GO sheet, whereby its morphology resembles a thin curtain or corrugated shape. The EDS spectrum of coated GO-F pellets revealed the distribution of C, O, N, P, and K elements in the synthesized materials. Afterwards, GO shell formation on fertilizer pellets greatly improved the slow-release characteristics of fertilizer, thus providing plants with their requisite nutrients and reducing environmental pollution.