Simple methods for immobilizing titania into pumice for photodegradation of phenol waste

Abstract

Simple methods for immobilizing titania into pumice were applied, where the products had been used for the application of photodegrading phenol waste. There were two simple methods, which were used separately: solvent evaporation and dip coating. Based on titania sol stability test, it was observed that acid condition would be favourable for immobilizing titania unto pumice, and preferable dispersion medium for solvent evaporation method was ethanol, while dip coating method was better to use aquadest (water). Prepared samples were characterized by FE-SEM, EDX, XRD, and BET analysis. Mechanical strength and photodegradation tests were conducted to observe the quality and ability of immobilized photocatalyst. Experimental results show that both methods had produced mechanically strong immobilized titania, where dip coating method tended to produce homogen solid film of titania on the outer surface of pumice, while solvent evaporation method could deliver titania deeper unto the inner part of the pumice. Catalyst detachment level of immobilized titania nanotube by dip coating method was 4.6%, while the one of the products of solvent evaporation method was 5.0%. Furthermore, in terms of photocatalytic activity, product of dip coating method gave slightly better performance (with 28% of phenol elimination after 240 min) than the product of solvent evaporation method (24%), due to shading effect, mostly occurring to immobilized catalyst in the inner part of the pumice.