One step to stabilize calcium sodium phosphate crystals acting as photocatalysts embedded in a glass matrix

Unstable calcium sodium phosphate (CaNaPO 4 ) in aqueous solution can be stabilized and shows photocatalytic activity in a glass matrix. This research presents one-step melt quenching to prepare stable CaNaPO 4 crystals in a glass material. The CaNaPO 4 glass ceramic was produced with stoichiometric amounts of SiO 2 , B 2 O 3 , P 2 O 5 , CaO, Na 2 O and TiO 2 at 1,200 °C for 4 h. The CaNaPO 4 glass ceramic samples were confirmed by XRD, SEM, and TEM techniques. The photocatalytic activity of the CaNaPO4 glass ceramic was investigated by monitoring methyl orange degradation with the addition of H 2 O 2 . Notably, the CaNaPO 4 glass ceramic demonstrates the high-efficiency photocatalytic degradation of methyl orange (MO) under UV irradiation. The CaNaPO 4 glass ceramic can be reused several times. After 8 cycles, the catalyst is still stable and effective in decomposing 100% of methyl orange within 5 h/cycle. In addition, the solid phase photocatalytic activity of the CaNaPO 4 glass ceramic was examined by bleaching adsorbed MB under UV light within 25 h. It can also inhibit the growth of E. coli bacteria after UV irradiation for 20 minutes. Therefore, the CaNaPO 4 glass ceramic might be an alternative photocatalytic material for wastewater treatment.