Various materials can be used to construct 3D electrodes, including metals, metal oxides, and carbon-based materials. For instance, platinum and palladium are commonly used due to their excellent catalytic properties. Metal oxides like titanium dioxide and manganese oxide are also popular choices because of their stability and catalytic activity. Carbon-based materials, such as graphene and carbon nanotubes, offer high conductivity and large surface areas, making them ideal for use in 3D electrodes.