Noble Metal Nanoparticle-Loaded Porphyrin Hexagonal Submicrowires Composites (M-HW): Photocatalytic Synthesis and Enhanced Photocatalytic Activity

Abstract

Surface plasmon resonance (SPR) photocatalysts have attracted considerable attention because of their strong absorption capacity of visible light and enhanced photogenic carrier separation efficiency. However, the separate production of metal nanoparticles (NPs) and semiconductors limits the photogenic charge transfer. As one of the most promising organic photocatalysts, porphyrin self-assemblies with a long-range ordered structure-enhance electron transfer. In this study, plasmonic noble metal-based porphyrin hexagonal submicrowires composites (M-HW) loaded with platinum (Pt), silver (Ag), gold (Au), and palladium (Pd) NPs were synthesized through a simple in situ photocatalytic method. Homogeneous and uniformly distributed metal particles on the M-HW composites enhanced the catalytic or chemical properties of the organic functional nanostructures. Under the same loading of metal NPs, the methyl orange photocatalytic degradation efficiency of Ag-HW [kAg-HW (0.043 min−1)] composite was three times higher than that of HW, followed by Pt-HW [kPt-HW (0.0417 min−1)], Au-HW [kAu-HW (0.0312 min−1)], and Pd-HW [kPd-HW (0.0198 min−1)]. However, the rhodamine B (RhB) and eosin B photocatalytic degradations of Pt-HW were 4 times and 2.6 times those of HW, respectively. Finally, the SPR-induced electron injection, trapping, and recombination processes of the M-HW system were investigated. These results showed that M-HW plasmonic photocatalysts exhibited excellent photocatalytic performances, making them promising materials for photodegrading organic pollutants.

Gamma Radiation Synthesis of Ag/P25 Nanocomposites for Efficient Photocatalytic Degradation of Organic Contaminant

“…The improved photocatalytic performance of Ag/P25 nanocomposites over P25 can be attributed to the enhancement of electron–hole separation and light utilization efficiency. Under Xenon light exposure ( Figure 10 ), the valence electrons of P25 become excited and transfer to the conduction band, and Ag NPs serve as electron traps to facilitate the electrons to participate in the reductive reaction of O 2 to O 2 − , as well as to prevent the recombination of electrons and holes [ 39 , 40 ]. Meanwhile, the LSPR effect of Ag NPs under visible light generates electron–hole pairs on their surface [ 61 ].…”

“…From previous research by Flores-Rojas et al [ 63 ], given a certain dose irradiation, lower dose rate induces larger particle size of Ag NPs because the production rate of reducing free radicals is slower than the association of ions with atoms. As shown in TEM image ( Figure 3 a–c), Ag NPs are formed in the shape of sphere, and the reduced particle sizes lead to bigger specific surface area and contact area with RhB and greatly enhance the surface-to-volume ratio of photocatalysts, which hence would improve the photocatalytic activity of Ag/P25 nanocomposites [ 40 , 47 ].…”

“…Moreover, the Z-scheme, a conceptual model in photosynthesis, has inspired researchers to design heterostructures and hybrid systems to preserve photogenerated electrons and holes with higher redox potentials and improve photocatalytic performance [ 38 ]. Among these modification methods, doping noble metal nanoparticles onto the surface of TiO 2 has proven particularly effective because the doped metal nanoparticles usually have high Schottky barriers, functioning as electron traps to enhance electron–hole separation and inhibit recombination of electrons and holes at the same time [ 39 , 40 ]. Additionally, the localized surface plasmon resonance (LSPR) effect triggered by the doped metal nanoparticles reduces the band gap width of metal-modified TiO 2 , extending its absorption range into the visible light spectrum [ 41 , 42 ].…”

Novel Laser-Assisted Chemical Bath Synthesis of Pure and Silver-Doped Zinc Oxide Nanoparticles with Improved Antimicrobial and Photocatalytic Properties

“…To address this challenge, noble metal-doped semiconductor nanoparticles have emerged as a promising strategy for augmenting photocatalytic activity. These materials have shown considerable potential by promoting charge transfer across the interface and facilitating the separation of photo-generated electrons and holes [64]. In particular, Ag-doped ZnO photocatalysts have attracted significant attention due to their exceptional photocatalytic performance and stability under various conditions.…”

Copper tungstate assisted photocatalytic degradation of Industrial (dye and pharmaceutical) products in water

“…Solutions to technological and environmental challenges in the elds of solar energy conversion, catalysis, medicine, and water remediation are offered by nanomaterials [24,25]. Researchers utilize metal oxide nanomaterials, including Fe 3 O 4 , TiO 2 , Al 2 O 3 , CuO, ZnO, and MgO, due to their versatile physical, chemical, and morphological properties that can be customized for speci c uses while manipulating the parameters of synthesis [26][27][28].…”