Protrudent electron transfer channels on kaolinite modified iron oxide QDs/N vacancy graphitic carbon nitride driving superior catalytic oxidation

Inorganic-Organic Dual-Ligand-Regulated Photocatalysis of CdS@ZnxCd1-xS@ZnS Quantum Dots for Lignin Valorization

In a dual-functional lignin valorization system, a harmonious oxidation and reduction rate is a prerequisite for high photocatalytic performance. Herein, an efficient and facile ligand manipulating strategy to balance the redox reaction process is exploited via decorating the surface of the CdS@ZnxCd1-xS@ZnS gradient-alloyed quantum dots with both inorganic ligands of hexafluorophosphate (PF6-) and organic ligands of mercaptopropionic acid (MPA). Inorganic ion ligands in this system provide a promotion for intermediator reduction reactions. By optimizing the ligand composition on the quantum dot surface, we achieve precise control over the extent of oxidation and reduction, enabling selective modification of reaction products; that is, the conversion rate of 2-phenoxy-1-phenylethanol reached 99%. Surface engineering by regulating the ligand type demonstrates that PF6- and thiocyanate (SCN-) inorganic ion ligands contribute significantly toward electron transfer, while MPA ligands have beneficial effects on the hole-transfer procedure, which is predominantly dependent on their steric hindrance, electrostatic action, and passivation effect. The present study offers insights into the development of efficient quantum dot photocatalysts for dual-functional biomass valorization through ligand design.

Morphology regulation of zero-valent iron nanosheets supported on microsilica for promoting peroxymonosulfate activation

Combing the assisted dispersion strategy of support with the wet chemical reduction method, a novel nano-zero valent iron/microsilica (nZVI/M) composite was successfully fabricated, where the 2D nZVI nanosheets were uniformly anchored and covered on the surface of microsilica. The introduction of microsilica notably relieved the agglomeration effect of nZVI nanosheets, which induced the improvement of specific surface area (45.68 m²/g) and pore volume (0.172 cm³/g), and thereby exposing more active sites for bisphenol A (BPA) removal. The optimized nZVI/M-0.6 displayed the superior catalytic performance in the presence of peroxymonosulfate (PMS) with the degradation rate of BPA reached above 97% within 3 min and a higher constant rate of 0.659 min^-1, which was approximately 3.9 times as high as that of nZVI/PMS system. The homogeneously dispersion of nZVI nanosheets on microsilica benefited for the assembly of the pollutants and boosting the kinetics of the catalytic degradation process. As a highly efficient PMS activator, it could well maintain the catalytic activity in different real water samples. The quenching experiments verified that SO₄^•- played the dominate role for BPA removal. This work offered novel insights for designing and preparing iron-based persulfate activator for wastewater treatment.