Al-Kimia, 10-2-2022, 140-150 Available online at: http://journal.uin-alauddin.ac.id/index.php/al-kimia Synthesis of MnO 2 as Supercapacitor Electrodes Material by Green Chemistry Method Through Dihydroxylation of Tangerine Peel (Citrus reticulata) Essential Oil Dewi Jalinan Izzah * , Fauziatul Fajaroh, Adilah Aliyatulmuna, Sumari Sumari, Siti Marfu’ah Department of Chemistry, Faculty of Mathematics and Science, The State University of Malang, Jl. Semarang 5, Malang City, Indonesia *Corresponding Author: dewijalinanizzah@gmail.com Received: August,22,2022 /Accepted: December,23,2022 doi: 10.24252/al-kimiav10i2.31459 Abstract: In this digital era, most technology requires electronic equipment. The performance of electronic equipment may be affected by energy storage components like a supercapacitor, so the development of supercapacitor electrode materials using green chemical methods needs to be pursued. Material with a good specific capacitance is MnO 2 . Most of the MnO 2 synthesis methods are not based on green chemistry, so there is an alternative method. One of them is by utilizing the waste from tangerine peels. This study aimed to synthesize MnO 2 through dihydroxylation of tangerine peel essential oil. The steps for conducting this research consisted of isolation of tangerine peel essential oil, analysis of the constituent components of tangerine peel essential oil, synthesis of MnO 2 through dihydroxylation of essential oils tangerine peel, and MnO 2 characterization. XRD results showed that MnO 2 synthesized at pH 11 had the highest percentage of α-MnO 2 (97%). This is evidenced by the presence of α-MnO 2 diffractogram according to the ICSD No.20227. The SEM results showed that MnO 2 had a spherical morphology with a particle diameter of 39.51 nm. α- MnO 2 has a larger tunnel structure compared to β- and γ-MnO 2 , making the charge-discharge process easier so that α-MnO 2 has the potential as a supercapacitor electrode material. Key word: Tangerine peel essential oil, green chemistry, MnO 2 , electrode, supercapacitor INTRODUCTION Energy needs in this digital era are increasing, so scientists in the world are developing various technologies, including energy storage components. This shows that technology is progressing so that it causes the importance of energy needs in high quantities. Electric vehicles, gadgets, and laptops include electronic equipment that requires energy storage components such as lithium-ion batteries. Lithium-ion batteries have the disadvantage of having a low density (<1 kW.kg -1 ) and short cycle life. Supercapacitors can be an alternative to lithium-ion batteries because they have a high density (>1 kW.kg -1 ) and long cycle life (F. Zhang et al., 2013). Supercapacitors are components that function to store electric charge high specific (Conway, 1999). To support the function of the supercapacitor, an electrode is needed as a primary component. Materials that have been used as supercapacitor electrode materials are MnO 2 (Wang, 2016) , Co 3 O 4 (Samal et al., 2017), RGO (Bhujel et al., 2019), NiCo 2 O 4 (Ko et al., 2017), and RuO 2 (Thangappan et al., 2018). MnO 2 was chosen as the supercapacitor electrode material in this study because of its low toxicity, environmental friendliness, and high specific capacity (1370 Fg -1 ) (Wang, 2016)compared to Co 3 O 4 (833 Fg -1 ) (Samal et al., 2017), RGO (50 Fg -1 ) (Bhujel et al., 2019), NiCo 2 O 4 (886 Fg -1 ) (Ko et al., 2017), and RuO 2 (441.1 Fg -1 ) (Thangappan et al., 2018).