Effects of annealing temperature on dealloying of Ti–Cu Alloy

• Annealing temperature has a big influence on microstructure of Ti33Cu67 ribbons.
• Sea-urchin-like TiO2 is fabricated by dealloying 500 °C (or above) annealed ribbons.
• TiO2 obtained from 500 °C annealed ribbons shows a good mechanical integrity.

A combined annealing–dealloying method is applied to process Ti33Cu67 alloy ribbons. This paper discusses the formation mechanism of nanostructured TiO2. With the increase of annealing temperature, phase segregation occurs and intermetallics of TiCu3 and Ti3Cu4 emerge. Multilayer TiO2 and sea-urchin-like rutile TiO2 were obtained by dealloying amorphous and crystalline ribbons in 65 wt.% HNO3 solutions, respectively. The original shape of the ribbon can be maintained by the as-dealloyed 550 °C (and 600 °C) annealed ribbons and they possess good mechanical integrity. In addition, sea-urchin-like TiO2 can slightly improve the photocatalytic performance of the degradation of methyl orange.