Photocatalytic mediated marine biofouling inhibition using nano CuO: TiO2-carbon dot embedded on organo silane surface modified polyethylene aquaculture cage nets

Biofouling in aquaculture cages is a potential problem and its management become major concern to the planners and farmers. The study aimed to modify the surface of polyethylene aquaculture cage nets using organo silane and to evaluate the effectiveness of a nano CuO:TiO2-carbon dot biocide treatment in inhibiting marine biofouling through photocatalytic action. Polyethylene aquaculture cage net surface modified using organo silane and the surface embedded with biocide of nano CuO:TiO₂ and carbon dot (CD) derived from fish eye. The biocide-treated surface was characterized using UV–Visible and Fourier Transform Infrared spectrometry. The organo silane interacts with polyethylene via hydrogen bonding, CuO:TiO₂ interacts with the silane's Si, and the carbon dots' conjugated CC bonds interact with the transition metal and silane through van der Waals electrostatic forces and hydrogen bonding. Varied concentrations of CuO:TiO₂ and CD was coated sequentially over silane surface modified polyethylene, exposed in the marine environment to evaluate biofouling inhibition efficiency and found 0.05% each of CuO:TiO₂ and CD was optimum. The CuO:TiO₂–CD coated polyethylene cage net tested for its biofouling inhibition for 8 months in marine environment and exhibited excellent biofouling inhibition. The inhibition of biofouling was attributed to the enhanced photocatalytic action, resulting from increased electron-hole recombination, thus generating ROS, O₂٠, and OH٠ radicals. This led to the highest electronic activity around the cage net and also the formation of an acidic environment deterred microorganisms. The study highlighted the use of organo silane for surface modification of polyalkenes to load the biocide and also CuO:TiO₂–CD is a potential biocide for biofouling inhibition in aquaculture cages.