Fabrication of Silica-Supported Al-Doped ZnO and Its Use in the Elimination of the Toxic Organic Ingredients from Industrial Effluents

Abstract

Herein, an easy co-precipitation method was adopted to fabricate Al-doped ZnO nanoflakes as a photocatalyst to remove noxious organic dye from industrial waste. The silica (SiO2) additive, owing to its network structure and excessive hydroxyl groups (Si-OH), has a great potential to capture dye molecules in its porous network. Application studies have shown that the Al-doped ZnO/SiO2 nanohybrid is more suitable for practical application because it eliminates almost 95 % of methylene blue (MB) dye after 120 minutes of exposure to solar light irradiation. The exceptional photodegradation efficiency of the Al-doped ZnO/SiO2 nanohybrid can be accredited to its narrower optical band gap, distinctive texture, hybrid composition, and good dye holding ability. The Al-doped ZnO nanoflakes exhibited a superior photocurrent response that was 4.60 times more than the bare ZnO response. Furthermore, EIS and Mott-Schottky studies reveal that the Al-doped ZnO catalyst facilitates the effective charge separation/transfer process and impedes electron-hole pair recombination, resulting in enhanced photocatalytic activity.