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.