A new type of plasmonic metal@TiO2 core–shell structure with well-controlled size, shape and shell thickness was prepared using a two-step surface modification process. The resultant structures take advantage of plasmonic hot spots, where the electromagnetic field is largely enhanced on sharp edges and corners of the metal cores, to generate high energy charge carriers. With tuneable light absorption property, large surface area, and excellent direct contact between the metal cores and crystalline TiO2 shells that facilitates the transfer of hot charge carriers, largely enhanced photodegradation reactivity for the metal@TiO2 core–shells was observed.