MECHANISM INVESTIGATION OF HYDROGEN EVOLUTION REACTION ON THE SURFACE OF TI3C2 MXENE NANOSHEETS

• Main Author: Pamungkas, Agam
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/82797
• Institution: Institut Teknologi Bandung

The use of fossil fuels continues to increase every year. The use of fossil fuels has a negative impact on the environment, for example increasing global temperatures and world climate change. Therefore, alternative clean and renewable energy sources are important to realize. Hydrogen (H2) is one of the best candidates as the newest clean energy source. The advantage of using hydrogen as an energy source is that the emissions are in the form of water, so it is not harmful to the environment. However, the electrochemical hydrogen production process through the hydrogen evolution reaction still has obstacles such as large overpotential values. This problem can be overcome by using an electrocatalyst which can reduce overpotential. Ti3C2 MXene is a two-dimensional nanomaterial oriented in the (002) direction. The Ti3C2 MXene nanomaterial has good performance in the hydrogen production process through the hydrogen evolution reaction. Researchers are still continuing to develop the best nanomaterials so that they can be a better option for carrying out the hydrogen production process. However, the reaction mechanism of hydrogen evolution on the surface of Ti3C2 MXene has not been comprehensively understood. This is important to carry out further engineering to improve the performance of the electrocatalyst. Therefore, this research conducted a computational study based on Density Functional Theory (DFT) to predict the best nanomaterial model and the most effective reaction route. Computational calculations were carried out using the PAW (Projector Augmented Wave) method with the generalized gradient exchange-correlation potential approach or GGA (Generalized Gradient Approximation) from Perdew, Burke, and Ernzerhof (PBE) on the VASP (vienna ab initio simulation package) computer code to calculate the structure electronics, predicting interactions, and material properties. The energy calculated from computing can provide an understanding of the hydrogen revolution reaction mechanism on the surface of the Ti3C2 MXene nanomaterial. VESTA software is used as a visualization tool for VASP calculation results to assist data interpretation. The research results show that the Ti3C2 MXene nanomaterial is metallic as indicated by density of state analysis and a band gap energy value of 0 eV. The value of hydrogen adsorption energy on the surface of the Ti3C2 MXene nanomaterial sheet without water molecules and with water molecules in the system is ?2.351 eV and ?2.002 eV, respectively. The research results also show that the hydrogen evolution reaction mechanism on the surface of the Ti3C2 MXene sheet tends to follow the Volmer-Heyrovsky pathway, with an activation energy value of 3.87 eV. This value is smaller than the Volmer-Tafel line with an activation energy of 6.24 eV. The hydrogen evolution reaction mechanism in the Ti3C2 MXene nanomaterial can be the basis for developing applications of this nanomaterial in the fields of catalysis and electrochemistry.