Preparation of cellulose-based carbon aerogel composite zinc oxide nanomaterials and their photocatalytic properties

Global environmental pollution has motivated the development of environmentally friendly photocatalysts. In this study, we successfully synthesised a carboxylated nanocarbon aerogel (NCA) as a substrate and loaded zinc oxide nanorods (ZnO NRs) onto NCA using a hydrothermal method. NCA/ZnO-1, NCA/ZnO-2, and NCA/ZnO-3 were prepared by adding different amounts of NCA and were used for the photocatalytic degradation of methyl orange (MO) dye under UV or visible light and then fully characterized. The NCA was found to have a graphitic carbon-laminate structure, which leads to a reduced NCA/ZnO bandgap and enhanced charge-carrier separation and transport. In addition, the porous carbon structure of NCA reduces the stacking density of the ZnO NRs so that they are well dispersed, providing more active sites, thereby improving the photocatalytic performance of NCA/ZnO. The catalytic degradation of MO using NCA/ZnO showed a significantly enhanced photocatalytic effect and better recyclability than ZnO alone. The complete degradation of MO by NCA/ZnO-2 under UV and visible light at pH = 9 took only 30 and 120 min, respectively, and the recovered NCA/ZnO-2 still had a catalytic performance of 99 % after recycling five times. This study provides new design ideas for the fabrication of three-dimensional semiconductor photocatalysts doped with carbon materials and opens a new path for renewable energy in combination with semiconductor applications.