Suspensible ZnTiO 3 /FAC Microspheres Facilitate Photocatalytic Degradation of Acid Red 1 and Recycling

ABSTRACT Fly ash cenosphere (FAC) was used as the substrate material in a sol–gel synthesizing route to prepare low‐density ZnTiO 3 /FAC microspheres. The loaded ZnTiO 3 layer was mainly comprised of ZnTiO 3 crystals in the cubic system with a smaller crystallite size. The porous structure of 40%ZnTiO 3 /FAC was mainly provided by the loaded ZnTiO 3 , but the specific surface area was only 1.26 m 2 /g. The bandgap energy of 40%ZnTiO 3 /FAC was calculated to be 3.77 eV. Although the photocatalytic degradation efficiency for Acid Red 1 increased with rising ZnTiO 3 content, 40%ZnTiO 3 /FAC was selected as the optimal sample with a propriate density, and the degradation efficiency was 89.1% after 60 min of reaction. The degradation efficiency of 40%ZnTiO 3 /FAC reused over six reaction cycles slightly decreased in the second and third cycles, while the degradation efficiency remained constant over the last four cycles. The ZnTiO 3 /FAC microspheres could be readily collected from the bottom of the water after the photocatalytic reaction for recycling of the photocatalyst.