Synthesis of mesoporous worm-like ZrO 2 –TiO 2 monoliths and their photocatalytic applications towards organic dye degradation

Abstract

Abstract The current article reports on the synthesis of a thermally stable mesoporous worm-like ZrO 2 doped TiO 2 monolith materials through a neutral templating route. The controlled thermal treatment facilitates clean removal of organic templates, resulting in a stable and well-defined porous framework. The ZrO 2 doped TiO 2 monoliths serve as an efficient and reusable photocatalyst materials for the photodegradation of Naphthol Green B (NG-B), a widely employed organic dye stain, within 10 min of irradiation time frame. The synthesized monoliths are characterized using techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDAX) spectroscopy, selected area electron diffractometry (SAED), UV–vis diffuse reflectance spectrophotometry (UV–vis–DRS), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), photoluminescence spectroscopy (PLS), and Brunauer–Emmett–Teller (BET) adsorption isotherm. The XRD analysis confirms the retention of anatase phase by the ZrO 2 doped TiO 2 monoliths and also the mesoporous structure. The DRS and PLS analysis indicate that the ZrO 2 doped TiO 2 monoliths exhibit band gap narrowing in comparison to pure TiO 2 monoliths, with improved quantum yield and photocatalytic efficiency. The BET analysis reveals a surface area and pore volume value of 80.2 m 2 /g and 8.1 nm, respectively, for ZrO 2 -TiO 2 monolith materials. We have also investigated on the influence of solution pH, dye concentration, dopant stoichiometry, photocatalyst dosage and photo-additives on the photocatalysis process.