Robabeh Bashiri

Application of Experimental Statistical Method in Optimizing Preparation Variables for Cu-Ni/TiO2 Photocatalyst

Cu-Ni/TiO2 was prepared using sol–hydrothermal method. Response surface Method (RSM) including central composite design (CCD) was applied to study the single and combined effects of three primary preparation parameters like water to alkoxide molar ratio (A), acid to alkoxide molar ratio (B), and Cu content (C) on the growth of Cu-Ni doped TiO2 particle size. The particle size range of the photocatalysts was 13−25 nm. Analysis of variance (ANOVA) revealed a second–order polynomial regression model to fit the experimental data in CCD. A comparison between predicted and experimental values has depicted a good agreement amongst them with high coefficient of determination value (R2= 0.98). The 3-D response surface and the contour plots imply a synergistic effect of parameter A, an antagonistic effect of parameter B, and significant interaction between them on the growth of particle sizes more than parameter C and its interactions with other variables. The smaller average sizes of Cu-Ni doped TiO2 particles with higher surface area are helpful to increase the light adsorptive property in hydrogen production studies.

Study on Synthesis and Characterization of Cu-Ni Doped TiO2 by Sol-Gel Hydrothermal

Titania (TiO2) as a semiconductor has been intensively studied during the last decades. Regardless of its superior photocatalytic performance and extensive environmental applications, it has a wide bandgap which lead to a photocatalytic activity only in ultraviolet (UV) irradiation. To shift the activity of TiO2 to visible region, a series of monometallic and bimetallic doped TiO2 was prepared with 10wt% total metals loading. The photocatalysts were synthesized by sol-gel associated via hydrothermal method. The properties of the photocatalysts such as crystal size, surface morphology, total surface area, chemical state of the elements, and bandgap were investigated by using thermogravimetric analysis (TGA), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and BrunauerEmmettTeller (BET) measurement. XRD analysis showed that all samples displayed anatase (101) as a main phase of TiO2 with average crystal size between 10-16 nm in a good agreement with the TEM results. The FESEM images show spherical particles less than 20 nm in size. The BET results indicated that all samples are mesoporous. The band gap of Ni-Cu/TiO2 is reduced to 2.65 eV with more absorbance in the visible region compared to those of cu/TiO2 and Ni/TiO2.

Effect of heat treatment on the physical properties of bimetallic doped catalyst, Cu-Ni/TiO2

Post heat treatment is critical for the doped semiconductor oxide in order to improve its photocatalytic performance. Thus work had been carried out to understand the effect of different calcination temperature (400, 450 and 500°C) on the physical properties of nanosized Cu-Ni/TiO2Cu-Ni doped TiO2 nanoparticles prepared using a combined method of sol-gel and hydrothermal. The treated samples were characterized using Raman spectroscopy, Brunauer–Emmett–teller (BET) measurement, high resolution transmission electron microscopy (HRTEM), field-emission scanning electron microscopy (FESEM), and diffuse reflectance UV-Vis spectroscopy (DR-UV-Vis). Raman analysis showed that all samples displayed anatase (101) phase of TiO2, which is in good agreement with the TEM results. BET data showed that all prepared Cu-Ni/TiO2 with different calcination temperature are mesoporous. SEM images displayed spherical particles with typical size of about 15 to 20 nm. UV-Vis spectra illustrated that the absorbance edge of all pre...

Investigation of photoconversion efficiency of Cu and Ni doped TiO2 thin film in photoelectrochemical cell

This paper presents the investigation on the optimal primary preparation parameters of Cu-Ni bimetallic supported TiO2 photocatalyst on photoconversion efficiency in photoelectrochemical cell (PEC). Three preparation parameters including, water, acid and copper dopant to Titanium tetraisopropoxide molar ratio was investigated. The single and combined impacts of these variables were examined by applying central composite design (CCD) from a response surface method (RSM). Quadratic polynomial regression models were proposed for the analysis of variance (ANOVA) to fit the experimental data in CCD. There was a good agreement in the linear relationship between the experimental and predicted values where model was fitted with high coefficient of determination value of 0.98. Data analysis had demonstrated that water and copper loading were two more effective parameters on the photoconversion efficiency compared to acid. The water molar ratio of 16, acid ratio of 3, and Cu loading of 7 mol % were the optimal prep...