Biological Renewable Cellulose-Templated Zn 1- X Cu X O/Ag 2 O Nanocomposite Photocatalysts for the Degradation of Methylene Blue.

Herein, Cellulose-templated Zn 1- X Cu X O/Ag 2 O nanocomposites were prepared using biological renewable cellulose extracted from water hyacinth ( Eichhornia crassipes ). Cellulose-templated Cu-doped ZnO catalysts with different amounts of Cu as the dopants (1, 2, 3, and 4%) were prepared and denoted CZ-1, CZ-2, CZ-3, and CZ-4, respectively, for simplicity. The prepared catalysts were tested for the degradation of methylene blue (MB), and 2% Cu-doped ZnO (CZ-2) showed the best catalytic performance (82%), while the pure ZnO, CZ-1, CZ-3, and CZ-4 catalysts exhibited MB dye degradation efficiencies of 54, 63, 65, and 60%, respectively. The best catalyst (CZ-2) was chosen to further improve the degradation efficiency. Different amounts of AgNO 3 (10, 15, 30, and 45 mg) were used for the deposition of Ag 2 O on the surface of CZ-2 and denoted CZA-10, CZA-15, CZA-30, and CZA-45, respectively. Among the composite catalysts, CZA-15 showed remarkable degradation efficiency and degraded 94% of MB, while the CZA-10, CZA-30, and CZA-45 catalysts showed 90, 81, and 79% degradation efficiencies, respectively, under visible light within 100 min of irradiation. The enhanced catalytic performance could be due to the smaller particle size, the higher electron and hole separation and charge transfer efficiencies, and the lower agglomeration in the composite catalyst system. The results also demonstrated that the Cu-doped ZnO prepared with cellulose as a template, followed by the optimum amount of Ag 2 O deposition, could have promising applications in the degradation of organic pollutants.