Temperature-Triggered Switchable Superwettability on a Robust Paint for Controllable Photocatalysis

Superwettability and photocatalysis are two important properties in interface science. Nowadays, photocatalysts with stable (super)hydrophilicity and (super)hydrophobicity have been widely studied. However, to endow long-termed switchable superwetting and photocatalysis on one surface is rarely reported. Herein, we prepared temperature (T)-triggered superwetting transitions on a paint for controlled photodegradations. The superwetting switches could be reversibly cycled for 50 times after sandpaper abrasion, knife scratch and finger wipe. Stable T-sensitive superwetting behaviors were observed for 50 hr UV irradiation. Meanwhile, UV-resistance ensured long-termed coexistence of switchable superwetting and photocatalysis. As for water-based dyes (Methyl blue, orange), our paint showed T-regulated photodegradations. The superhydrophobic surface at 50°C possessed less contacted catalytic sites and earned a lowest degradation rate (DR) of 15.0%. Inversely, a highest DR of 95.5% was obtained on 10°C-senstive superhydrophilic surface because of sufficient contacted catalytic sites. This work indicates the promising applications in various fields of materials and chemistry.