Leilei Yin,Yuyan Liu,Shuai Zhang,Jin-Cheng Liu,Yong Jiang,Yaping Du
Excessive adsorption of oxygen-containing intermediates during oxygen reduction reactions (ORR) on palladium (Pd)-based materials is a critical factor limiting their catalytic activity. Alloying presents a powerful strategy to overcome this inherent challenge. In this study, the alloying of the low electronegativity lanthanide gadolinium (Gd) with Pd is explored. Pioneering theoretical calculations indicate that Gd, acting as an electron donor, induces charge redistribution between the metals. This process weakens the over-adsorption of OH* intermediates on the Pd surface and reduces the reaction overpotential. Subsequent experiments yield Pd 3 Gd solid-solution nano-alloys supported on conductive carbon black (Pd 3 Gd/C-600), resulting in a 30 mV enhancement in half-wave potential and a 4.5 fold increase in mass activity in an alkaline medium compared to Pd/C-600. Due to its superior performance in ORR, Zn-air batteries utilizing Pd 3 Gd/C-600 cathodes demonstrate remarkable peak power density and stability over 330 h. This study offers valuable insights into the rational design of rare earth alloys and their catalytic chemistry in ORR.
Multifunctional theranostic nanoplatforms (NPs) in response to environment stimulations for on-demand drug release are highly desirable. Herein, the near-infrared (NIR)-absorbing dye, indocyanine green (ICG), and the antitumor drug, doxorubicin (DOX), were efficiently coencapsulated into the thermosensitive liposomes based on natural phase-change material. Folate and conjugated gadolinium (Gd) chelate-modified liposome shells enhance active targeting and magnetic resonance performance of the NPs while maintaining the size of the NPs. The ICG/DOX-loaded and gadolinium chelate conjugated temperature-sensitive liposome nanoplatforms (ID@TSL-Gd NPs) exhibited NIR-triggered drug release and prominent chemo-, photothermal, and photodynamic therapy properties. With the coencapsulated ICG, DOX, and the conjugated gadolinium chelates, the ID@TSL-Gd NPs can be used for triple-modal imaging (fluorescence/photoacoustic/magnetic resonance imaging)-guided combination tumor therapy (chemotherapy, photothermotherapy, and photodynamic therapy). After tail vein injection, the ID@TSL-Gd NPs accumulated effectively in subcutaneous HeLa tumor of mice. The tumor was effectively suppressed by accurate imaging-guided NIR-triggered phototherapy and chemotherapy, and no tumor regression and side effects were observed. In summary, the prepared ID@TSL-Gd NPs achieved multimodal imaging-guided cancer combination therapy, providing a promising platform for improving diagnosis and treatment of cancer.
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