Yuyu Fang

Fundamentally, the type-II and Z-scheme heterojunctions exhibit identical band alignments but diverge in the charge carriers transfer mechanisms. Here, we demonstrate that the Au-mediated heterojunction transition from type-II to Z-Scheme dictates the subsequent photocatalytic NO reaction pathway to obtain excellent activity and selectivity. As proven by density functional theory (DFT) calculations, Kelvin probe force microscopy (KPFM) and in-situ X-ray photoelectron spectroscopy (in-situ XPS), the type-II to Z-scheme heterojunction transition is regulated by incorporating Au nanoparticles as electron bridges within in-situ fabricated NH₂-MIL-125/TiO₂ through controllable hydrolysis. This transition maintains robust redox potentials to generate more reactive active species through effectively separated charge carriers under the high-efficient built-in electric field. As a result, the Z-scheme (NH₂-MIL-125/Au/TiO₂) exhibits an impressive 82.0% NO removal efficiency, surpassing the original NH₂-MIL-125 by 3.7 times and the type-II (NH₂-MIL-125/TiO₂) by 1.2 times, while shows almost 100% selectivity toward NO₂⁻/NO₃⁻. The in-situ Fourier transform infrared (in-situ FT-IR) and DFT reveal that, in comparison with the type-II favored NO⁺ intermediates, the Z-scheme favors NO⁻ intermediates with enhanced O₂/H₂O activation, enabling ideal Gibbs free energy for NO-to-NO₃⁻ conversion. This study achieves a metal-nanoparticle-mediated strategy for precisely engineering MOFs-based heterojunction architectures, which regulates the NO reaction pathways for efficient environmental purification.

The fusion of heterocycles onto an anthraquinone scaffold represents a promising strategy to optimize anticancer activity. This study has the aim to synthesize and characterize novel anthra[1,2-b]furan compounds based on the natural product aloe-emodin. Six novel anthra[1,2-b]furans bearing phenyl, n-hexane, and methoxy carbonyl substituents were synthesized starting from aloe-emodin. The synthetic route employed involved acetyl protection of aloe-emodin, electrophilic aromatic halogenation, subsequent Castro–Stephens coupling, spontaneous intramolecular cyclization, and deprotection of hydroxyl groups. These newly synthesized compounds were evaluated for their cytotoxic activity against various cancer cell lines, including lung adenocarcinoma (A5492), colorectal carcinoma (HCT116), hepatocellular carcinoma (HepG2), ovarian cancer (Skov3), and breast cancer (MCF-7), using the CCK8 assay. The anthra[1,2-b]furan derivative 10c, which contains a methoxy carbonyl group, demonstrated excellent potency against lung (A549) and breast (MCF-7) cancer cell lines, with IC₅₀ values of 0.49 and 2.91 µM, respectively. This preliminary cytotoxic finding shows compound 10c as a promising hit for further investigations towards a promising lead compound.