(436h) ZrO2 Incorporated ZnO/TiO2 Mesoporous Photocatalyst for H2 Generation

The present research deals with the synthesis of ZrO₂ incorporated coupled ZnO/TiO₂ photocatalyst and its effectiveness on H₂ generation from aqueous methanol solution.  Ordered mesoporous ZrO₂ supported coupled TiO₂/ZnO materials were synthesized using surfactant as structure directing agent, titanium isopropoxide, zinc acetate dihydrate and zirconium n-propoxide precursors.  The ZrO₂ incorporated coupled ZnO/TiO₂composites were characterized by XRD, UV-Vis spectra, SEM/TEM, XRF, Raman and N₂ adsorption-desorption isotherm.  Photocatalytic hydrogen evolution was carried out in a 7 mL quartz reactor at ambient temperature.  The focused intensity and area on the quartz cuvette were 0.60 W and 2 cm², respectively.  In a typical experiment, 2.0 mg of ZrO₂/ZnO-TiO₂ photocatalyst was dispersed in 3.5 mL of H₂O containing 0.5 mL methanol or 10 mg biomass as a sacrificial agent.  A 300 W xenon lamp (Oriel) equipped with a UV-filter (240 nm - 400 nm) was employed as the light source.  Prior to irradiation, the suspension of the catalyst was degassed with ultrapure nitrogen for 30 min to completely remove the dissolved oxygen and to ensure the reactor in an anaerobic condition.  From 3 mL reactor overhead space, 0.1 mL of gaseous samples were withdrawn periodically and analyzed using the gas chromatograph (GC), from which photocatalytic effectiveness towards H₂  generation was evaluated and compared with coupled  TiO₂/ZnO material.