• Photocatalysis;
  • Titanium;
  • Ceramics;
  • Waste prevention;
  • Freeze casting


A highly porous TiO2 ceramic floating photocatalyst was successfully synthesized by using ethanediamine-modified Degussa P25 as precursor, followed by a camphene-based freeze-casting process and high-temperature calcination. The ceramics were characterized in detail by XRD, SEM, and TEM. The results indicate that an ethanediamine protector can inhibit undesirable titania grain growth and phase transformation during calcination. The porosity and compressive strength of the ceramics varies with sintering temperatures; the optimal sintering temperature, 800 °C, produces high porosity, high compressive strength, and high photocatalytic activity. The ceramics exhibit good photocatalytic activity for the photodegradation of rhodamine B (10 mg L–1), and the total organic carbon removal efficiency is up to 96.7 % after 5 h. The photocatalytic kinetics of rhodamine B removal are pseudo-first order. The ceramics are recyclable, and no clear changes are observed after six cycles. Furthermore, the ceramics are also active in phenol, thiobencarb, atrazine, and octane. Therefore, this novel floating photocatalyst will likely have wide applications, including the removal of soluble organic pollutants from wastewater or the removal of oil pollutants from wastewater surfaces.