Mxene-based lithium-ion sieve polymer membrane for sustainable lithium adsorption

•Realizing recycle of lithium-ion sieve powder by casting HTO/MXene@PVC film.•Improving pore structure and mechanical properties through the incorporation of MXene.•Enhancing adsorption performance of the film due to the increased pore volume. Lithium, an emerging mineral of critical global significance, is recognized as a strategic resource by major economies worldwide, leading to an increased demand for this essential element. The extraction of lithium from rich sources, such as seawater and brine, has become commonplace. Among various liquid lithium extraction techniques, the lithium-ion sieve (LIS) adsorption method has attracted substantial attention owing to its simplicity, high recovery rate, and relatively low energy consumption. Despite significant advancements in LIS technology, the powdery nature of these materials poses challenges to handling and recycling, leading to inevitable adsorbent loss and limited practical applications. LISs are typically recycled through powder shaping, but the commonly employed shaping methods may result in a reduction in the adsorbent’s adsorption capacity. Therefore, it is urgent to develop a technology that can not only realize the recycling of LISs but also avoid the loss of the adsorbent’s adsorption capacity. We synthesized a titanium-based LIS (HTO) hybrid membrane by incorporating 2D MXene, known for its excellent properties across various applications. The incorporation of MXene into the membrane significantly increased the pore structure, enhancing adsorption site exposure and facilitating Li+ migration. The HTO/MXene@PVC hybrid film demonstrated favorable adsorption properties, with an Li+ adsorption capacity of 25.4 mg·g−1 within 24 h. Additionally, the film exhibited notable selectivity capacity and maintained its adsorption capacity above 90 % even after eight adsorption–desorption cycles, indicating excellent cycling performance. This study introduces a novel design concept for adsorbents, specifically for extracting Li+ from liquid lithium sources, offering new insights for the development of Li+ adsorbents aimed at enhancing lithium recovery.