DEVELOPMENT OF MXENE/TIO2-BASED PHOTOCATALYST FOR PHOTODEGRADATION OF METHYLENE BLUE

• Main Author: ILLAHI, CARENE
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/83369
• Institution: Institut Teknologi Bandung

Methylene blue is a dye compound that is quite often used as a material in the textile industry because it can provide attractive colors, but methylene blue has a negative impact on the environment. This is due to the difficulty of decomposing methylene blue waste which is toxic to the environment. Photocatalysis is one effective solution to degrade methylene blue. The effectiveness and efficiency of dye degradation are highly dependent on the properties of the photocatalyst used. In this study, the photocatalysts developed was based on MXene/TiO2. MXene plays a role in the process of electron-hole pair formation in semiconductors. MXene Ti3C2 was synthesized from MAX Ti3AlC2, while MXene Ti2C and V2C were synthesized from Ti2AlC and V2AlC, respectively. MXene/TiO2 photocatalysts were obtained through synthesis by combining TiO2 and MXene with a mechanochemical method and used in the photodegradation of in aqueous methylene blue solutions. On the synthesized compounds, IR, XRD, UV-Vis DRS, and SEM characterizations were carried out. Measurement of photocatalytic activity can be observed from the percentage of dye degraded during lighting. The results showed that MXene/TiO2 photocatalyst has better dye photodegradation activity compared to pure TiO2 semiconductor. In its use, MXene/TiO2 photocatalyst has good enough stability so that it does not have a significant impact if used repeatedly. Therefore, MXene/TiO2 photocatalyst has great potential in the present and future for textile and dyeing industry wastewater treatment as a neutralizer of the environmental impact of methylene blue. In this study, MXene Ti3C2, Ti2C, and V2C were successfully synthesized from MAX Ti3AlC2, Ti2AlC, and V2AlC with the disappearance of the (104) diffraction peak and shifting of (002) diffraction peak and rapid decrease in intensity of the (103) diffraction peak in MAX V2AlC, and shifting of the (002) diffraction peak in Ti2AlC. The synthesis of MXene/TiO2 composite was successfully synthesized with the presence of complete TiO2 peaks in the composite and the absence of MXene peaks indicating that MXene is evely distributed. Measurement of gap energy with the Kubelka-Munk and Tauc plot equations obtained gap energy from TiO2, Ti3C2/TiO2 (mass ratio 1:10, 1:25, dan 1:50), V2C/TiO2 (mass ratio1:10) and Ti2C/TiO2 (mass ratio 1:10) which are respectively 2.979 eV; 2.511 eV; 2.741 eV; 2.832 eV; 2.869 eV, and 0.143 eV. Urbach tail energy measurements were obtained for TiO2, Ti3C2/TiO2 (mass ratio 1:10, 1:25, dan 1:50), V2C/TiO2 (mass ratio 1:10), and Ti2C/TiO2 (mass ratio 1:10) which are respectively 0.142 eV; 0.485 eV; 0.284 eV; 0.290 eV; 0.233 eV, and 3.225 eV. In this study, the photodegradation test produced observed rate constant values of methylene blue with trend that shows that the use of MXene/TiO2 photocatalyst increases the observed rate constand values of methylene blue. The kobs values of methylene blue with the addition of Ti3C2/TiO2 (mass ratio 1:10, 1:25, and 1:50), Ti2C/TiO2 (mass ratio 1:10), and V2C/TiO2 (mass ratio 1:10) in the full lighting treatment for 90 minutes are sequentially 20.4 × 10?3min??; 6.09 × 10?3 min?1; 2.49 × 10?3 min?1; 0.29 × 10?3 min?1; and 23.2 × 10?3 min?1. Meanwhile, the kobs value of methylene blue with the addition of Ti3C2/TiO2 (mass ratio 1:10), Ti2C/TiO2 (mass ratio 1:10), and V2C/TiO2 (mass ratio 1:10) in the treatment of being left in the dark and lighting for 60 minutes respectively are 7.79 × 10?3 min?1; 0; and 10.1 × 10?3 min?1.