Indonesia Conference Directory

Corresponding Author
Fahdzi Muttaqien

Institutions
a) Department of Computational Sciences, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132, Indonesia

b) Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132, Indonesia

c) Research Center for Nanosciences and Nanotechnology, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132, Indonesia

Abstract
Study the adsorption and reactivity of CO2 on surfaces are of great interest in technological application and fundamental sciences. Moreover, CO2 reduction into more valuable compound has been also the most effective strategy to reduce the green house effect in the atmosphere. Nowadays, graphene has been proposed as a support of catalytic materials to adsorb and reduce CO and CO2. Graphene becomes more reactive when we introduce transition metal as an adatom or dopant.[1,2] In this research, we focus on elucidating the adsorption of CO2 on pristine graphene, and graphene with Ni adatom and dopant. We performed density functional theory (DFT) study of CO2 adsorption on graphene with and without Ni adatom/dopant. We implemented van der Waals (vdW) interaction correction to accommodate weakly interaction between CO2 and graphene. In addition to those, we also compared our results with general PBE calculations. Based on vdW functional calculations, we obtained that CO2 is physisorbed on pristine graphene with adsorption energy of 0.17 eV. Meanwhile, PBE shows almost repulsive interaction between CO2 and graphene. These results are in good agreement with previous works.[3] Single Ni adatom/dopant and small Ni cluster increase the activity of graphene. We obtained that CO2 is more stable on graphene with Ni adatom rather than with Ni dopant. It turns out that Ni adatom is more reactive than Ni dopant. We noticed that Ni adatom and dopant have different local properties of electronic d states. The difference in local d state may cause variations in reactivity.[4,5] The adsorption energy further increases when we introduced small Ni cluster on graphene. The adsorbed CO2 bond angle on graphene with Ni adatom/dopant and small cluster is distorted from its gas phase condition of 180°, indicating that CO2 is chemisorbed on the decorated graphene area. Our results then provide useful insight into appropriate design of graphene supported metal catalysts. References: [1] X. Liu, Y. Sui, T. Duan, C. Meng, and Y. Han, Phys. Chem. Chem. Phys. 16, 23584-23593 (2016). [2] H. Xu, W. Chu, W. Sun, C. Jiang, and Z. Liu, RSC Adv. 6, 96545-96553 (2016). [3] K. Takeuchi, S. Yamamoto, Y. Hamamoto, Y. Shiozawa, K. Tashima, H. Fukidome, T. Koitaya, K. Mukai, S. Yoshimoto, M. Suemitsu, Y. Morikawa, J. Yoshinobu, and I. Matsuda, J. Phys. Chem. C 121, 2807 (2017). [4] B. Hammer, Y. Morikawa, and J. K. Nørskov, Phys. Rev. Lett. 76, 2141-2144 (1996). [5] B. Hammer, Surf. Sci. 459, 323-348 (2000).

Keywords
CO2 adsorption; Graphene; Catalytic activity

Topic
Computational Physics

Link: https://ifory.id/abstract/8rZm6WYaH3Fh

Corresponding Author
Meqorry Yusfi

Institutions
a) Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung, Indonesia
*meqorryyusfi[at]sci.unand.ac.id
b) Research Center for Nanosciences and Nanotechnology, Institut Teknologi Bandung, Bandung, Indonesia
c) Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Padang, Padang, Indonesia

Abstract
The adsorption of C2H2 and C2H4 gas molecules on Ni-doped singe-wall carbon nanotubes (Ni-CNT (10,0)) was investigated using Density functional theory (DFT). To discover the highest binding energy, three Ni-CNT configurations that are bridge, hollow, and top position of Ni on CNT were calculated. The Ni on the bridge configuration was found to be the most stable configuration based on binding energy and Ni-C bond length analysis. As addition of Ni to CNT, the band gap energy of CNT becomes narrower from 0.879 eV to 0.289 eV. The C2H4 adsorption energy was acquired stronger than C2H2 which resulting a smaller band gap. Also, the geometry change of the gases/Ni-CNT was investigated in this research. This result would be useful to proposed Ni-CNT as an active material for hydrocarbon gas sensor.

Keywords
CNT, Ni, Adsorption energy, DFT, band gap

Topic
Computational Physics

Link: https://ifory.id/abstract/gTLEvpq9cu6Y

Corresponding Author
Riri Jonuarti

Institutions
a) School of Energy, Bandung Institute of Technology
Jalan Ganesha 10, Bandung 40132, Indonesia
*riri.jonuarti[at]gmail.com
b) Department of Physics, Universitas Andalas, Jalan Universitas Andalas, Limau manis, Padang, 25163,
Indonesia

Abstract
Density functional theory (DFT) combined with random phase approximation (RPA) was used to determine the dielectric function of (5,0) zigzag and (5,5) armchair boron nitride carbon nanotube (BNCNT). The concentration of carbon atoms in the BNCNT structures varies by 20%, 30%, 40%, 50% and 60% of the total number of atoms in the structure. The results of the optical properties depicted in the dielectric function graphs for each (5,0) zigzag and (5,5) armchair BNCNT. The effect of each quantity of the carbon concentrations to the optical properties of those nanotubes is also discussed. The large concentration of carbon atoms in one BNCNT structure makes the dielectric constant increase which is indicated on the graph of the dielectric function at the energy point 0 eV by a real scale height. Furthermore, the large carbon concentration in the (5.5) BNCNT creates a new absorption peak at 0 eV energy. So that, by understanding that the concentration of carbon atoms in the BNCNT framework affects the optical properties of these hybrid materials, the material can be implemented in multiple applications.

Keywords
Density Functional Theory; Random Phase Approximation; Boron Nitride Carbon Nanotubes; The Concentration of Carbon; Optical Properties

Topic
Computational Physics

Link: https://ifory.id/abstract/Y3xruwtWcpU9