Fabrication of visible light driven nano structured Copper, Boron codoped TiO2 for photocatalytic removal of Lissamine Green B

Abstract

In the present research work a potentially improved Copper (Cu) and Boron (B) codoped TiO2 nano materials were synthesized by varying the different dopant concentrations (Copper 0.25, 0.50, 0.75, 1 wt% and Boron 0.25, 0.50, 0.75, 1 wt%) using solgel method for the photocatalytic degradation of Lissamine Green B. In order to investigate the physical, chemical and optical properties of a catalyst, which play a key role in its photocatalytic activity, as prepared samples were characterized by various instrumental techniques. The crystalline phase study performed for all the samples using X-ray powder diffraction (XRD) confirmed the formation of anatase TiO2. Chemical composition of the prepared catalyst investigated by X-ray photo electron spectroscopy (XPS) affirmed the presence of constituent elements (Ti, O, Cu & B) on the catalyst surface. The surface microstructure studied by field emission scanning electron microscopy (FE-SEM) revealed that the TiO2 particles having spherical shape with rough surface morphology. The average particle size and surface area of the catalyst determined by high-resolution transmission electron microscopy (HRTEM) and Brunauer-Emmett-Teller (BET) surface area analyser, revealed that the codoped catalyst shows a high percentage of small particles of size 6.8 nm and a high surface area of 135.6 m2/g, respectively. The band edge absorption shift of the samples was determined by diffuse reflectance spectroscopy analysis (DRS) and the results exhibited that among all the codoped samples Copper 0.25 wt% and Boron 1 wt% (CBT1) catalyst shows a reduced band gap energy of 2.73 eV. The characterization results supported the photocatalytic activity of the catalyst for the degradation of Lissamine Green B within 90 min at the optimum reaction parameters such as dopant concentration of Cu at 0.25 wt% & B at 1 wt%, pH = 3, catalyst dosage 0.075 g/L and dye concentration 10 mg/L under visible light irradiation. The mechanism of enhanced photocatalytic performance of the catalyst was proposed by the results obtained from the PL spectra and main reactive species trapping measurements.