MXENE?BASED NANOCOMPOSITE AS PHOTOCATALYST FOR BICARBONATE REDUCTION AND ELECTROCATALYST FOR HYDROGEN EVOLUTION REACTION

• Main Author: Ayu Chairuna Natalya, Suci
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/65265
• Institution: Institut Teknologi Bandung

The increasing consumption of fossil fuels and their negative impacts have encouraged the development of renewable energy sources. Conversion of bicarbonate to formic acid through photocatalytic reaction and electrocatalysis of water (H2O) through Hydrogen Evolution Reaction (HER) to hydrogen (H2) has attracted much attention as a sustainable pathway. Both reactions require an efficient catalyst. MXene is a two?dimensional transition metal carbide?based material which has a large surface area, abundant functional groups, structurally and chemically stable, and has high electrical conductivity. These characteristics make MXene potential as an efficient photocatalyst and electrocatalyst. The addition of MXene can prevent electron recombination, accelerate charge separation, broaden the light absorption range, and enhance electron conductivity. In addition, Au nanoparticle is able to increase the catalyst response in the visible light region, reduces the rapid light recombination due to the effect of SPR (Surface Plasmon Resonance), and stabilizes the formation of H2. MXene can be modified to enhance its performance as a photocatalyst and electrocatalyst. In this study, MXene (Ti3C2Tx) was modified with TiO2 and/or Au nanoparticle as a photocatalyst for the reduction of bicarbonate to formic acid and electrocatalyst of HER. MXene/TiO2, Au/MXene/TiO2, Au/MXene, and Au/TiO2 were synthesized. MXene?based catalysts were characterized using Fourier Transform Infra?Red Spectroscopy (FT?IR), Raman Spectroscopy, X?Ray Diffraction (XRD), Scanning Electron Microscope?Energy Dispersive X?Ray (SEM?EDX), and UV–Vis Diffuse Reflectance Spectroscopy (UV?Vis DRS). These characterizations have confirmed MXene?based catalyst was successfully synthesized. Bicarbonate reduction into formic acid resulted the activity of MXene/TiO2 (0.2) (2.3710 mmol/g catalyst) > Au/MXene/TiO2 (1.4858 mmol/g catalyst) > Au/TiO2 (1.4045 mmol/g catalyst) > TiO2 (1.1612 mmol/g catalyst). These results are consistent with the trend of band gap energy and Urbach tail energy. HER activity resulted Au/MXene as the best electrocatalyst with an overpotential value of 179.9 mV, onset potential of 87.6 mV, Tafel slope of 91 mV/dec, Electrochemical Active Surface Area (ECSA) of 54 cm2, and increase stability by 13.03% after 10 hours reaction.