Construction of high-performance Ce-doped TiO₂ tight UF membranes for protein separation

The membrane structure and properties have a significant influence on its anti-fouling performance during the separation process. In this study, Ce was introduced to inhibit the phase transformation of TiO₂ to obtain a tight ultrafiltration (UF) membrane with a more uniform pore size, a more integrated membrane layer as well as to strengthen the membrane surface charge to provide superior anti-fouling performance for the membrane during protein separation. Single anatase phase of the material proves that the introduction of Ce effectively inhibited the phase transformation of TiO₂ and prevented the occurrence of cracks. The prepared Ce-doped TiO₂ membrane exhibited excellent performance, with a membrane thickness of 700 nm, water permeance of 175 L·m⁻²·h⁻¹·bar⁻¹ and molecular weight cut-off of approximately 18 kDa. Additionally, it showed excellent BSA separation performance, as the stable permeance and rejection rate could be maintained at 120 L·m⁻²·h⁻¹·bar⁻¹ and 100 %, respectively. Meanwhile, Ce-doped TiO₂ membrane showed superior anti-fouling performance compared to pure TiO₂ membrane due to its strengthened surface charge and uniform pore size, with the J/J0 maintained a value of 0.69. Based on the obtained results, the Ce-doped TiO₂ membranes prepared in this study exhibit good potential for protein separation.