Synthesis and photocatalytic property of Au-TiO₂ nanocomposites with controlled morphologies in microfluidic chips

We present an efficient approach for the consecutive synthesis of Au-TiO₂ nanocomposites with controlled morphologies in a microfluidic chip. The seed-mediated growth method was employed to synthesize Au nanorods as the core, and TiO₂ layers of varying thicknesses were deposited on the surface or tip of the Au nanorods. Au-TiO₂ nanocomposites with core-shell, dumbbell, and dandelion-like structures can be precisely synthesized in a one-step manner within the microfluidic chip by finely tuning the flow rate of NaHCO₃ and the amount of hexadecyl trimethyl ammonium bromide. Furthermore, we have investigated the photocatalytic activity of the synthesized nanocomposites, and it was found that Au NR-TiO₂ core-shell nanostructure with a thin TiO₂ shell exhibits superior catalytic performance. This work provides an effective and controlled method for the microscale preparation and photocatalytic application of various Au-TiO₂ nanocomposite structures.