GO-KNO3 fertilizer: Slow release fertilizer innovation from coconut shell waste as a solution to Indonesian food security

Background: As a country with a large agricultural sector, using fertilizers is an essential factor. Inorganic fertilizers such as KNO3 are an option, but excessive use of fertilizers results in the accumulation of inorganic residues. The use of fertilizers that can release controlled nutrients is very necessary, one of which is by encapsulating with Graphene Oxide (GO). Methods: Coconut shell waste is used as the primary material for making GO which is synthesized by the Hummer method with variations in the mass of coconut shell graphite, the characterization of graphene oxide was Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and Atomic Absorption Spectrophotometry (AAS). Findings: This research aims to synthesize GO and determine its characteristics as an encapsulation of KNO3 fertilizer. Conclusion: The FTIR results obtained in this research detected O-H bonds, C-H bonds, and C = C bonds. In TEM characterization, thin morphology results were obtained, indicating an oxidation process in the formation of graphene oxide. The AAS showed that the release of KNO3 from graphene oxide was maximum after 8 hours with a percentage of 93.8%. This fertilizer will be used to solve the problem of low plant absorption of macronutrients contained in fertilizers. Novelty/Originality of this article: Encapsulating KNO₃ fertilizer using GO to control nutrient release is a novel approach. This technique addresses the challenge of nutrient overuse and minimizes the environmental impact of inorganic fertilizers.背景：作为农业大国，肥料施用是农业生产的核心要素。硝酸钾（KNO₃）等无机肥料虽为常用选择，但过量施用会导致无机残留物累积。开发可实现养分可控释放的肥料极具必要性，其中一种途径便是采用氧化石墨烯（Graphene Oxide, GO）进行包封。 方法：本研究以椰壳废料为制备氧化石墨烯的核心原料，采用Hummer法合成，实验设置了椰壳基石墨质量梯度变量。采用傅里叶变换红外光谱（Transform Infrared Spectroscopy, FTIR）、X射线衍射（X-Ray Diffraction, XRD）、透射电子显微镜（Transmission Electron Microscopy, TEM）以及原子吸收分光光度法（Atomic Absorption Spectrophotometry, AAS）对氧化石墨烯进行表征。 研究结果：本研究旨在合成氧化石墨烯，并明确其作为硝酸钾肥料包封材料的性能特征。 结论：本研究所得傅里叶变换红外光谱结果检测到了O-H键、C-H键以及C=C键。透射电子显微镜表征结果显示样品呈现超薄形貌，表明氧化石墨烯制备过程中发生了氧化反应。原子吸收分光光度法检测结果表明，硝酸钾从氧化石墨烯载体中的释放量在8小时后达到峰值，释放率为93.8%。该肥料可用于解决植物对肥料中大量营养素吸收效率低下的问题。 本文创新性与原创性：采用氧化石墨烯包封硝酸钾肥料以实现养分可控释放，是一种全新的技术路径。该技术可应对养分过量施用的难题，同时降低无机肥料对环境的负面影响。