SYNTHESIS AND CHARACTERIZATION OF POROUS SODIUMALUMINOSILICATE DECORATED WITH NICKEL AND PALLADIUM

Abstract

Zeolites due to their porous nature are called molecular sieves and have a lot of industrial applications. They are microporous, mesoporous and nanoporous materials which attract much attention due to their unique structural properties. Sodiumaluminosilicate decorated with Ni and Pd is synthesized by hydrothermal treatment at 1200 C for 12 hrs. Molar ratio of the mixture, alkalinity, aging conditions, crystallization temperature and reaction time are important factors for the synthesis of mesoporous sodiumaluminosilicate. The material is characterized by Diffused reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Thermogravimetric analysis (TG), Scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET). The UV-visible spectroscopy shows the absorbance edge at 260 nm and the band gap is 3.6 V calculated from tauc plot showing the efficient capturing of photons in UV and Vis region to generate electron and holes efficiently. IR bands at 670, 990, 1051, 1660 and 3375 cm-1 indicating Al-O bending vibration, Si-OSi asymmetric stretching vibration, Al-O-Si asymmetric stretching vibration, H-O-H stretching vibration and OH groups of Si-OH stretching vibration respectively. XRD shows the peaks of support (aluminosilicate) only and the metal peaks are not detectable because of their addition in less amount. TGA shows no loss in mass. SEM/EDS shows layered structure having canals, pores and voids in between the layers with homogenously distributed nickel and palladium nanoparticles. TEM shows the presence of channels, pores and voids at various resolutions. The BET surface area is 875.178 m2/g and Langmuir surface area is 1230.638 m2/g. In this thesis, two aims are highlighted which are hydrogen storage and photoelectrochemical studies for water splitting. Due to its porous framework, hydrogen can be adsorbing in the voids of sodium aluminosilicate where metals are incorporated. The water splitting results are analyzed for Chronoamperometry (CA) and water stability are studied.