Effect of Ti/P ratio on structure, crystallization behaviour and photocatalytic activity of MgO–TiO2–P2O5–Al2O3–SiO2 glass-ceramics

In the present work, MgO–TiO2–P2O5–Al2O3–SiO2 glasses with different Ti/P ratios were prepared by the melt-quenching method, and Mg0.5Ti2(PO4)3 glass-ceramics were obtained by controllable crystallization. The effects of the Ti/P ratio on the structure, crystallization behaviour, and properties of the glasses and glass-ceramics were studied by FTIR, DSC, XRD, EDS, UV–Vis DRS, and so on. The results show that with the increase of the Ti/P ratio, the content of the [TiO6] group and Ti–O–P bond in the glass network increases, which strengthens the cross-linking of the glass network. However, the decrease of glass former P2O5 reduces the thermal stability of the glass. The appropriate Ti/P ratio is beneficial to the formation of single-phase glass-ceramics, and the band gap width of glass-ceramics containing single Mg0.5Ti2(PO4)3 crystal phase is 3.0 eV. With the irradiation of a high-pressure mercury lamp for 120 min, the glass-ceramics after crystallization at 850 °C for 4 h can effectively degrade MB dye solution (41%∼75%). The potential application prospect of the prepared glass-ceramics in the field of water purification of organic dyes was confirmed.