Photocatalytic activity of bismuth vanadate (BiVO4) for acetaldehyde decomposition under visible light irradiation was improved by inclusion of a nanocomposition of silica as an adsorbent material and loading of platinum (Pt) or trivalent iron ion (Fe3+) as reduction cocatalysts. Addition of silica enhanced photocatalytic activity due to improvement of adsorption ability, but total decomposition of acetaldehyde was not observed within 24 h of visible light irradiation. For further improvement of photocatalytic activity, BiVO4 with an optimized amount of silica composition were modified with Pt or Fe3+. Photodeposition of Pt greatly increased photocatalytic activity, and acetaldehyde was totally decomposed within 24 h of visible light irradiation. (c) 2011 Elsevier B.V. All rights reserved.