Confinement of Sn-Cu synergized low-lead CsSn0.7Cu0.1Pb0.2Br3 quantum dots in halloysite nanotubes toward stable and sustainable optoelectronic applications

The commercialization of cesium lead halide perovskite quantum dots (QDs) is hindered by lead toxicity and poor stability. We propose a synergistic “chemical-physical” dual-confinement strategy. Chemically, Sn 2 + and Cu 2+ are co-doped into CsPbBr 3 , forming low-lead CsSn 0.7 Cu 0.1 Pb 0.2 Br 3 QDs, where Sn 2+ tunes the bandgap and Cu 2+ passivates Sn-related defects. Physically, QDs are in-situ grown within halloysite nanotubes (HNTs), a natural clay, serving as a nanoreactor and barrier. Silane modification enhances hydrophobicity. The composite exhibits high photoluminescence quantum yield (73.46%), excellent thermal reversibility, and remarkable water resistance (86% intensity retention after 12 h). Applications include a wide-color-gamut white light-emitting diode (122.1% of National Television System Committee (NTSC)) and an efficient visible-light photocatalyst for methylene blue degradation. This work provides a sustainable pathway for stable, low-toxicity perovskite materials in optoelectronics and environmental remediation.