Single-ion conducting solid polymer electrolytes (SICSPEs) offer a promising route towards safe solid-state lithium metal batteries, yet their Li+ conduction remains limited by sluggish Li+ dissociation from immobilised anions and subsequent migration through polymer matrices. Herein, we report a dual-regulation strategy that couples anion coordination-environment engineering with polymer segmental dynamic activation to accelerate Li+ transport. By enabling the in situ growth of zeolitic imidazolate framework-8 (ZIF-8) within a poly(ethylene glycol) methyl ether methacrylate-2-acrylamido-2-methylpropane sulfonic acid (PEGMEM-AMPS) copolymer matrix, Lewis acid-base interactions are established between the Lewis-acidic Zn centres of ZIF-8 and immobilised sulfonate groups. These interactions weaken Li+-sulfonate association and promote Li+ dissociation, while ZIF-8 simultaneously suppresses ethylene oxide crystallinity and enhances segmental dynamics to facilitate Li+ migration. The resulting SICSPE delivers a high Li+ conductivity of 6.48 × 10−3 S cm−1, a Li+ transference number of 0.95, and a wide electrochemical stability window of 5.9 V. Solid-state LiFePO4//Li cells employing the as-synthesised SICSPE demonstrate promising rate capability and long-term cycling stability with dendrite-free lithium metal deposition. This work highlights the proposed dual-regulation strategy as an effective design principle for overcoming coupled ion-dissociation and ion-migration limitations in high-performance SICSPEs for solid-state lithium metal batteries.
Visible-light photocatalysis over metal-modified TiO2 is commonly interpreted in terms of enhanced reactive oxygen species (ROS) generation; however, the relationship between ROS production and effective pollutant mineralization remains poorly understood. Here, TiO2 photocatalysts modified with various noble and transition metals were prepared via ball milling (BM) and incipient wetness impregnation (IWI) to investigate how metal-support interactions influence charge-transfer pathways. Among all investigated systems, Pt/TiO2 prepared by ball milling (Pt/TiO2-BM) exhibited markedly enhanced photocatalytic mineralization of bisphenol A (BPA), despite generating only negligible coumarin-detectable •OH radicals in the bulk solution. In contrast, Au- and Ag-containing catalysts produced substantially higher ROS signals yet showed inferior mineralization efficiency. These findings reveal a pronounced disconnect between bulk ROS generation and photocatalytic mineralization efficiency. Combined spectroscopic and photocatalytic analyses provided evidence for a strongly coupled, oxygen-deficient Pt-TiO2 interface formed through ball milling, associated with Ti3+ centers, oxygen-vacancy-related states and intense visible photoluminescence centered at approximately 600 nm, consistent with the formation of Pt-induced interfacial electronic states. The emergence of these states was associated with photocatalytic behaviour consistent with localized, surface-confined oxidation pathways and highly efficient BPA mineralization despite low bulk ROS generation. Conversely, catalysts prepared by incipient wetness impregnation showed behaviour consistent with a greater contribution from non-selective bulk ROS pathways, resulting in lower mineralization efficiency despite stronger radical generation in solution. The results indicate that photocatalytic efficiency under visible light depends strongly on the nature and localization of interfacial charge-transfer pathways rather than simply on the total ROS concentration generated in the bulk phase. Overall, this work highlights mechanochemical control of metal-TiO2 interfaces as a promising strategy for directing photocatalytic oxidation pathways and improving visible-light photocatalytic efficiency.
