Raihan Mahirah Ramli

Visible Light Photodegradation of Azo Dye by Cu/TiO2

Cu/TiO2 photocatalysts with different metal loading were prepared via modified depositionprecipitation method with the intention to reduce the band gap for Orange II degradation and mineralization under visible light radiation. The photocatalysts were characterized using thermal gravimetric analysis, powder X-ray diffraction, diffuse reflectance UV-Visible spectroscopy and field-emission scanning electron microscopy. 10 wt% photocatalysts showed the best performance compared to the bare TiO2.

Visible-Light Photodegradation of Diisopropanolamine Using Bimetallic Cu-Fe/TiO2 Photocatalyst

Titania nanoparticles, TiO2 were synthesized via microemulsion method prior to monometallic (Fe, Cu) or bimetallic (CuFe) incorporation using wet impregnation method. The prepared photocatalysts were characterized using X-ray diffraction, field emission scanning electron microscopy, diffuse reflectance UV-Vis spectroscopy and point of zero charge. The addition of metals, especially Cu enhanced the absorbance in the visible region. The lowest band gap was observed for the bimetallic Cu-Fe/TiO2 (2.77 eV) compared to bare TiO2 (3.05 eV). The performance of the photocatalysts for photodegradation of diisopropanolamine (DIPA) at pH 8 was determined using a batch glass reactor under simulated sunlight (980 W/m2). The best performance was displayed by Cu-Fe/TiO2 with the highest DIPA removal of 92%.

Photodegradation of Aqueous Diisopropanolamine Using Cu/TiO2: Effect of Calcination Temperature and Duration

The effects of calcination temperature and duration during preparation of Cu/TiO2 photocatalyst were investigated. The photocatalysts were characterized using X-ray and BET specific surface area analyzer. It was observed that the temperature and duration during calcination process have a significant effect on the photocatalyst properties and photocatalytic activity. Optimum temperature and duration for the calcination of the synthesized photocatalyst were found to be at 450 °C and 1.5 h, respectively. Photodegradation study of aqueous diisopropanolamine solution (1000 ppm) using the prepared photocatalyst showed a significant COD removal under visible light irradiation. The photocatalyst calcined at optimum parameters gave the highest COD removal of 63%.

Evaluation of CO2 emission from dye solar cell panel production process

The generation of electricity from solar panel is considered generally to be a zero CO2 emission process. However, closer look at the life cycle of the solar panel system will show that the most significant activity that contribute to CO2 emission is the process energy for producing the solar panel itself where it requires energy input from the fossil power plant. Ideally, the generated CO2 emission during the production process should be much lower and able to compensate the CO2 emission after the operation of the solar panel. This report highlight the amount of CO2 savings after 20 years of solar panel life time with 1643.28 kg of CO2 per m2 of dye solar cell (DSC) panel. Comparison of this third generation PV with the reported data of silicon-based PV, showed that the production process of DSC solar panel emitted approximately 50% lower CO2.

Optimization of Cu/TiO2 Preparation Variables Using Response Surface Method for Photodegradation of Diisopropanolamine

The Cu/TiO2 photocatalyst preparation variables namely Cu loading, calcination temperature and calcination duration were optimized using response surface methodology. A set of experiments were conducted to obtain the response data which was then analyzed using Design Expert software. The analysis of variance revealed that COD removal from aqueous DIPA solution fitted a quadratic polynomial model with high coefficient of determination (R2 = 0.99). The Cu loading was found to be the most significant variable, which then followed by calcination time and the least significant variable was calcination temperature. The optimum condition for the preparation of Cu/TiO2 photocatalyst for photodegradation of aqueous diisopropanolamine solution was observed at 1.8 wt% Cu loading calcined at 425 °C for 1.0 h. At the optimum condition, 61.15 % of COD removal was achieved. The optimum conditions of the current study will be used for kinetic study.

Photocatalytic Degradation of Diisopropanolamine in Heterogeneous Photo-Fenton System

Photodegradation of 100 ppm diisopropanolamine (DIPA) was studied employing heterogeneous photo-Fenton system using iron modified TiO2 photocatalyst. A series of Fe/TiO2 photocatalysts were prepared via hydrolysis-hydrothermal and wet impregnation methods. Photocatalysts prepared using wet impregnation method was found to have similar activity under both UV and visible light. Addition of H2O2 during the photodegradation study obviously promoted the COD removal efficiency. When stoichiometric concentration of H2O2 was added, as high as 80% of COD was removed within 1.5 h reaction. Further modification is required to increase the photocatalyst performance in photodegradation of DIPA.

Visible Light Photodegradation of Diisopropanolamine Using Cu/TiO2 Photocatalyst: Effect of Metal Loading

Cu doped TiO2 at different metal loading was successfully prepared and investigated. Characterization of the prepared photocatalysts was carried out using X-ray diffraction (XRD), diffuse reflectance UVVis spectroscopy (DRUVVis) and scanning electron microscopy (SEM). Photodegradation study of aqueous diisopropanolamine solution (1000 ppm) using the prepared photocatalyst showed significant COD removal under visible light irradiation. The photocatalyst with 1.5 wt% Cu gave the highest COD removal of 45 %.