Sulfuric Acid-Free Synthesis of Electrochemically-Exfoliated Graphene (EEG) as An Eco-Friendly Counter-Electrode Material for Dye-Sensitized Solar cells
Nenden Fauziah (a,b,c), Nadiatus Silmi(a,b), Fairuz Gianirfan Nugrohod,(e), Kemal Lesmana Hidayat Putra (b), Brian Yuliartoe (f), Rahmat Hidayat (e,g), Veinardi Suendo(b,e)(*)

(a)Doctoral Program of Chemistry, Faculty of Mathematics and Natural Sciences, Department of Chemistry, Institut Teknologi Bandung, Bandung 40132, Indonesia
(b)Division of Inorganic and Physical Chemistry, Institut Teknologi Bandung, Bandung 40132, Indonesia-
(c)Chemistry Division, Universitas Garut, Garut, Indonesia
(d)Master^s Program in Nanotechnology, Graduate School, Institut Teknologi Bandung, Bandung 40132, Indonesia
(e)Research Center for Nanosciences and Nanotechnology, Institut Teknologi Bandung, Bandung, Indonesia
(f)Advanced Functional Materials (AFM) Laboratory, Department of Engineering Physics, Institut Teknologi Bandung, Bandung 40132, Indonesia.
(g)Division of Magnetic and Photonic Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung, Indonesia
(*)Corresponing author e-mail: vsuendo[at]chem.itb.ac.id

Abstract

A more environmentally friendly synthesis route of electrochemically-exfoliated graphene (EEG) materials through electrochemical exfoliation can be achieved without sulfuric acid as the exfoliating medium. Therefore, the ammonium sulfate solution was adopted as a substitute for sulfuric acid during the electrochemical exfoliation. As a result, the exfoliation process took twice as long as with the sulfuric acid. The morphology and chemical constituents were analyzed using SEM-EDS and observed that all EEGs have amorphous morphology with a homogeneous chemical distribution. Raman analysis shows that the ammonium sulfate exfoliated EEG (EEG_B) has more defects than the sulfuric acid exfoliated EEG (EEG_A). Therefore, the PANI-EEG_B composite performs better than the PANI-EEG_A composite material when applied as a counter-electrode in DSSC. The performance of PANI-EEG_B (&#61544- = 1.71%) as a counter-electrode in DSSC is even better than the Pt counter-electrode (&#61544- = 1.49%). Thus, applying EEG_B with PANI as an electrode composite in CE leads to a higher-performing and more eco-friendly DSSC.

Keywords: Ammonium sulfate, counter-electrode materials, Dyes-sensitized solar cells, Electrochemically-exfoliated graphene, Exfoliating medium, Sulfuric acid.

Topic: CHEMISTRY AND MATERIAL SCIENCES