Uswatul Chasanah
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara, Yogyakarta 55281, Indonesia

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Role of Temperature and Time Exposure for Controlled and Accelerated Synthesis of Graphene Oxide Using Tour Method Uswatul Chasanah; Wega Trisunaryanti; Haryo Satriya Oktaviano; Triyono Triyono; Dyah Ayu Fatmawati
Indonesian Journal of Chemistry Vol 22, No 5 (2022)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.71817

Abstract

Synthesis of graphene oxide (GO) with the Tour method has been studied. In this procedure, phosphoric acid was mixed with sulfuric acid in the ratio of 1:9, and then potassium permanganate and graphite with the ratio of 6:1 was added in an ice bath at the variation of oxidation times of 1, 7 and 24 h and temperatures of 40, 50 and 60 °C. The GOs were characterized by UV–Visible spectroscopy, Fourier Transform InfraRed (FT-IR) spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy-Energy Dispersive X-Ray (SEM-EDX), and Transmission Electron Microscopy (TEM). The results show that the GO oxidized at 40 °C for 7 h (GO-7-40) has been successfully formed indicating that GO-7-40 is the most efficient GO. The GO-7-40 is characterized by a peak at 2θ = 10.89° in the XRD diffractogram, resulting calculation of the average distance between graphene layer (d) of 0.81 nm. The average number of graphene layers (n) is 4, the oxidation level (C/O) is 1.50 according to EDX data, λmax at 226 nm attributes to π→π* transitions of C=C bond in UV-Vis spectrum, and the functional groups such as O-H, C=C, C-OH, and C-OC are observed in FT-IR spectrum.
Microwave-Assisted Chemical Co-reduction of Pd Nanoparticles Anchored on Reduced Graphene Oxide with Different Loading Amounts Dyah Ayu Fatmawati; Triyono Triyono; Wega Trisunaryanti; Uswatul Chasanah
Indonesian Journal of Chemistry Vol 22, No 5 (2022)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.73206

Abstract

Microwave-assisted Palladium/Reduced Graphene Oxide (Pd/RGO) synthesis was effectively carried out in this study, which looked at the effects of different Pd loading weights in Graphene Oxide (GO) on its physicochemical qualities. The Tour technique was used to make GO, with a KMnO4:graphite weight ratio of 3.5. Meanwhile, Pd/RGO was synthesized utilizing the in-situ reduction method of one-pot synthesis with ascorbic acid as the green reducing agent, yielding Pd-0.5/RGO, Pd-1.0/RGO, and Pd-2.0/RGO, respectively, with variations in Pd loading weight of 0.5, 1.0, and 2.0%. XRD, FTIR, SAA, SEM-EDX, and TEM were used to examine all material characterizations. As a result, Pd-1.0/RGO had the largest surface area of 65.168 m2/g among the Pd-based materials, with a pore volume of 0.111 cc/g, the pore diameter of 3.316 nm, Pd crystallite size of 28.29 nm, RGO nanostructure dimension of 3.37 × 28.53 nm, and reduction level (C/O) of 3.02. This material also contains specific functional groups, including O-H, C-H, CO2, C=C, C=O, and C-O, based on FTIR spectra. Therefore, optimal weight loading of metal on the surface of the supporting material will provide a large material surface area. Increasing the surface area of the material improves its performance as a catalyst.