Characterization and photocatalytic properties of porous ZrO2/Al2O3 ceramic bead supported BiOI catalyst

Porous ZrO2/Al2O3 ceramic bead carriers were prepared through the gel-dripping method using sodium alginate as gelling agent with sucrose as pore-forming agent. The BiOI photocatalyst was loaded on the porous ceramic bead carrier with the solvothermal method. The effects of sucrose content and sintering temperature on the pore structure, porosity and compressive strength of the carriers were investigated. The influences of reaction time and reaction temperature on the microstructure and visible light photocatalytic properties of supported BiOI catalyst were also studied. The results show that, the porous ceramic bead with 30 wt% sucrose content sintered at 1300 °C exhibits a porosity of 71.60 % and a compressive strength of 5.06 MPa, which is suitable for the catalyst carrier. BiOI nanosheets assemble into microspheres with bonding force in the supported BiOI catalyst. BiOI microspheres distribute on the surface or in the pores of carriers. The supported BiOI catalyst prepared at 160 °C soaking for 6 h exhibits the highest degradation rate of 98.5 %. The microsphere diameter, loading amount, and photocatalytic activity of supported BiOI can be regulated through optimizing the reaction time and reaction temperature of solvothermal method. Compared with BiOI powder, the supported BiOI catalyst is easily recycled.