RESUMO
Palladium nanoparticles find extensive applications in catalysis in both homogeneously and heterogeneously catalyzed processes. Supporting metal nanoparticles enhances their stability as compared to their unsupported counterparts. The role of catalytic support is increasingly recognized as crucial in determining the behaviour of these materials. However, controlling the deposition and anchoring of palladium nanoparticles remains a significant challenge. This contribution discusses the preparation of straight lines of palladium particles on zinc oxide by wet impregnation. This phenomenon is attributed to the highly stepped morphology of the employed ZnO that created steric anchoring sites to stabilize the metal particles. Palladium-based catalysts were evaluated for the valuable Suzuki-Miyaura cross-coupling reaction. The dispersed Pd/ZnO catalyst achieved a conversion rate of 86% with 100% selectivity, remarkably superior to that of the Pd/Al2O3 and Pd/TiO2 counterparts.
RESUMO
The rapid industrialization of the world is disparagingly manipulating our environment and natural ecosystem. The researchers are taking keen interest to invent novel material as photocatalyst for non-degradable organic pollutants. Solar energy-driven practices employing semiconductors are a novel approach towards wastewater remediation. Here in, we successfully synthesized a vigorous photocatalysts comprising of g-C3N4 and doped ZnO-W/M (M = Co, Ce, Yb, Sm) by co-precipitation followed by metals doping via calcination approach. The structural, morphological, and photocatalytic applications for organic pollutants of synthesized heterostructure nanocomposites were examined by XRD, FTIR, SEM, EDX and UV visible spectrophotometer. Diffraction peaks attributed to both g-C3N4 and ZnO-W were detected in the XRD spectra. The FTIR spectra also inveterate the formation of g-C3N4/ZnO-W/M composites. The SEM images reveal an agglomerated morphology and EDS analysis also confirmed close contact between g-C3N4, ZnO-W and doped metals. The abridged energy band gap of g-C3N4/ZnO-W/M (M = Ce, Yb, Sm, Co) nanocomposites calculated via Tauc plot are 2.68, 2.88, 3.24 and 3.29 eV respectively. Narrowing of bandgap is considered an imperative triumph for the degradation of industrial effluents. The photocatalytic activity was performed against four different dyes and follows the trend Ce > Yb > Sm > Co. The recyclability tests were carried out for different dyes and no substantial catalytic activity loss was observed even after the fourth experimental run, which proves that reported ternary heterojunctions exhibit high mechanical stability and reusability.The species trapping experiment exposed that generated h+ are the principal active specie for dye photodegradation reactions. This work disseminates a novel photocatalyst for the removal of synthetic dyes.