Impact of Ag nanoparticles on photomineralization of chlorobenzene by TiO2/bentonite nanocomposite

- The Ag-TiO2/bentonite nanocomposites were synthesized from simple microwave synthesis of TiO2/bentonite followed by wet impregnation of AgNPs.
- For the first time investigation regarding effect of weight% of AgNPs on photocatalytic activity of TiO2/bentonite has been carried out.
- The as prepared Ag-TiO2/bentonite nanocomposites were highly effective in photocatalytic mineralization of chlorobenzene taken as model water pollutant.
- Due to their insoluble nature, the Ag-TiO2/bentonite nanocomposite retained its reusability efficiency upto 85-92% after five runs under visible light.

TiO2/bentonite nanocomposite was prepared by microwave irradiation method. Different quantities of Ag (0.5-3% by weight) were loaded to the nanocomposite by wet impregnation process to investigate their effect on the photocatalytic activity. Morphological and elemental analysis of the as-synthesized nanocomposites were carried out by field emission scanning electron microscope (FESEM), high-resolution transmission electron microscope (HRTEM), energy dispersive spectroscopy (EDS), inductively coupled plasma-Auger electron spectroscopy (ICP-AES) and X-ray photoelectron spectroscopy (XPS). Crystallographic studies were carried out by X-Ray diffraction analysis (XRD). From nitrogen adsorption-desorption (BET-Brunauer Emmett Teller) analysis it was found that surface area and pore volume decreased upon Ag loading but pore size distribution was not much affected in the nanocomposites. The absorption edge and band gap of the nanocomposites were found to be red-shifted after Ag loading as observed from UV-vis DRS (diffuse reflectance spectroscopy) spectra. The prepared Ag-TiO2/bentonite nanocomposites were found to be effective for photocatalytic degradation of harmful volatile organic compounds (VOCs) like chlorobenzene under both UV and visible light. The nanocomposite containing 1.5% of Ag was found to be highly active in degrading chlorobenzene both in UV and visible light.

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