Sintesis Carbon Dots dari Kulit Pisang yang Diperkaya Nitrogen Sebagai Nano-Fertilizer pada Pertumbuhan Vegetatif Awal Jagung

Abstract

Nano fertilizer merupakan fertilizer (pupuk) berukuran nano yang dapat diserap dengan cepat oleh tanaman dan didistribusikan ke seluruh bagian tanaman. Nano fertilizer organik seperti carbon dots (CDs) berbahan dasar karbon hijau dapat dijadikan pilihan dalam pembuatan nano-fertilizer yang ramah lingkungan dan tidak beracun. Bahan dasar karbon hijau yang digunakan dalam penelitian ini adalah limbah kulit pisang raja nangka (pisang nangka). Penelitian ini bertujuan untuk menyintesis nano-fertilizer CDs dan CDs dengan pengayaan nitrogen (N-CDs) dari kulit pisang nangka dengan menggunakan metode microwave, mengetahui karakteristik CDs dan N-CDs serta mengetahui bagaimana kinerja keduanya terhadap pertumbuhan vegetatif awal jagung dalam hal tinggi tanaman, jumlah daun, jumlah kandungan klorofil relatif, diameter batang, berat basah brangkasan, berat basah akar dan panjang akar. CDs urea 0% dan N-CDs urea 10% dipilih sebagai objek perbandingan gugus fungsi CDs dan N-CDs. CDs dan N-CDs tersebut memiliki beberapa kesamaan gugus fungsi misalkan adanya gugus hidroksil C(=O)OH dan beberapa perbedaan gugus fungsi yang dimiliki N-CDs tapi tidak dimiliki CDs tersebut yakni C=C-C, C-O-O, C-Cl, ????2 - ?? - ???? dan CS. Berkenaan dengan energi celah pitanya, CDs 40 mg/L urea 0% dan N-CDs 40 mg/L urea 10% dipilih untuk mewakili perbandingan energi celah pita pada CDs dan N-CDs. CDs kulit pisang nangka 40 mg/L urea 0% memiliki energi celah pita sebesar 2.46 eV dan CDs kulit pisang nangka 40 mg/L urea 10% memiliki energi celah pita sebesar 3.99 eV. CDs 40 mg/L memancarkan panjang gelombang emisi 512.15 dengan intensitas 8267 a.u. Baik CDs maupun N-CDs tersebut sama-sama menghasilkan pendar cahaya yang berwarna sian (biru kehijau-hijauan), namun pada N-CDs warna sian yang dipancarkan lebih redup. Begitu pula dengan citra Confocal Laser Scanning Microscope (CLSM) pada daun tanaman jagung pada kelompok percobaan CDs 40 mg/L urea 0% dan N-CDs 40 mg/L urea 10% yang secara berurutan menghasilkan panjang gelombang emisi 505 nm dan 496 nm. Analisis regresi linear peubah-peubah yang diteliti terhadap CDs per level urea menyatakan bahwa urea 5% paling optimal dalam meningkatkan pertumbuhan awal tanaman jagung. Semakin tinggi kadar CDs semakin baik dalam meningkatkan pertumbuhan awal tanaman jagung.

IZZATUT TAQIYYAH. Synthesis of Nitrogen-Enriched Carbon Dots from Banana Peel as Nano-Fertilizer for the Vegetative Growth of Maize. Supervised by AKHIRUDDIN MADDU and RAHMAD SUHARTANTO. Nano-fertilizer is a fertilizer in nano-sized form that can be rapidly absorbed by plants and distributed throughout all parts of the plant. Organic nano-fertilizers such as carbon dots (CDs) made from green carbon sources can be a suitable choice for producing environmentally friendly and non-toxic nano-fertilizers. The green carbon material used in this research was waste from jackfruit banana (a cultivar of banana) peel. This research aimed to synthesize CDs and nitrogen-enriched CDs (N-CDs) from jackfruit banana peel using the microwave method, characterize the CDs and N-CDs, and investigate their effects on the early vegetative growth of maize in terms of plant height, number of leaves, relative chlorophyll content, stem diameter, fresh shoot weight, fresh root weight, and root length. CDs with 0% urea and N-CDs with 10% urea were selected as comparison objects for analyzing the functional groups of CDs and N-CDs. The CDs and N?CDs shared several functional groups, such as hydroxyl groups (C(=O)OH), but also had differences. N-CDs possessed additional functional groups not found in CDs, such as C=C-C, C-O-O, C-Cl, ????2 - ?? - ???? and ????. Regarding the band gap energy, CDs with 40 mg/L urea 0% and N-CDs with 40 mg/L urea 10% were selected to represent the comparison. CDs derived from jackfruit banana peel with 40 mg/L urea 0% had a band gap energy of 2.46 eV, whereas those with 40 mg/L urea 10% had a band gap energy of 3.99 eV. The 40 mg/L CDs emitted a light wavelength of 512.15 nm with an intensity of 8267 a.u. Both the CDs and N-CDs emitted cyan light (bluish-green); however, the cyan light emitted by N-CDs was dimmer. Similarly, Confocal Laser Scanning Microscope (CLSM) images of maize leaves from the treatment groups of 40 mg/L urea 0% CDs and 40 mg/L urea 10% N-CDs showed emission wavelengths of 505 nm and 496 nm, respectively. Linear regression analysis of the investigated variables regarding CDs at each urea level revealed that 5% urea was the most optimal in promoting early maize growth. The higher the concentration of CDs, the more it improved early maize plant growth.