Noble metal enhanced photocatalytic activity of heterostructured TiO2 spheres with tunable interiors and shells

2020 ◽  
Vol 13 (08) ◽  
pp. 2050039
Author(s):  
Bo Qiu ◽  
Xin Xiao ◽  
Min Zhang ◽  
Yue Mao ◽  
Xiaoheng Liu

Heterostructured TiO2 spheres with tunable interiors and shells were prepared by self-template technology. This structure is composed of a hollow shell and an inner core which can enhance light scattering in the hollow space and provide a large surface to generate sufficient active sites. Besides, the nanosheets grown on the shell layer not only increased their specific surface area, but also exposed more surface-active sites. The performance of photocatalysts was estimated by the RhB decolorization, and experimental results show that the photoactivity can be greatly improved by depositing noble metal nanoparticles. It improves the efficiency of charge utilization and enhances the overall catalytic performance from the three stages of charge carrier generation, separation and surface reaction. The strong metal–support interaction (SMSI) between the noble metal nanoparticles and the oxide support has been proven to inhibit the supported precious metal, one strategy for nanoparticle aggregation and growth. On the one hand, the nanoshells isolate the precious metal nanoparticles from each other, preventing the aggregation of metal nanoparticles.

2019 ◽  
Vol 55 (48) ◽  
pp. 6846-6849 ◽  
Author(s):  
Weikang Ji ◽  
Xuyu Wang ◽  
Minni Tang ◽  
Le Yang ◽  
Zebao Rui ◽  
...  

We report a facile surface fluorination strategy for restricting Pt nanoparticle sintering through providing anchoring sites on the TiO2 support and enhancing metal–support interaction via improved electronic interaction without sacrificing the active sites.


2012 ◽  
Vol 1 (1) ◽  
pp. 31-56 ◽  
Author(s):  
Rongchao Jin

AbstractThis review article focuses on the impacts of recent advances in solution phase precious metal nanoparticles on heterogeneous catalysis. Conventional nanometal catalysts suffer from size polydispersity. The advent of nanotechnology has significantly advanced the techniques for preparing uniform nanoparticles, especially in solution phase synthesis of precious metal nanoparticles with excellent control over size, shape, composition and morphology, which have opened up new opportunities for catalysis. This review summarizes some recent catalytic research by using well-defined nanoparticles, including shape-controlled nanoparticles, high index-faceted polyhedral nanocrystals, nanostructures of different morphology (e.g., core-shell, hollow, etc.), bi- and multi-metallic nanoparticles, as well as atomically precise nanoclusters. Such well-defined nanocatalysts provide many exciting opportunities, such as identifying the types of active surface atoms (e.g., corner and edge atoms) in catalysis, the effect of surface facets on catalytic performance, and obtaining insight into the effects of size-induced electron energy quantization in ultra-small metal nanoparticles on catalysis. With well-defined metal nanocatalysts, many fundamentally important issues are expected to be understood much deeper in future research, such as the nature of the catalytic active sites, the metal-support interactions, the effect of surface atom arrangement, and the atomic origins of the structure-activity and the structure-selectivity relationships.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1890
Author(s):  
Xiang Lai ◽  
Xuan Zhang ◽  
Shukai Li ◽  
Jie Zhang ◽  
Weifeng Lin ◽  
...  

Water soluble organic molecular pollution endangers human life and health. It becomes necessary to develop highly stable noble metal nanoparticles without aggregation in solution to improve their catalytic performance in treating pollution. Polyethyleneimine (PEI)-based stable micelles have the potential to stabilize noble metal nanoparticles due to the positive charge of PEI. In this study, we synthesized the amphiphilic PEI-oleic acid molecule by acylation reaction. Amphiphilic PEI-oleic acid assembled into stable PEI-oleic acid micelles with a hydrodynamic diameter of about 196 nm and a zeta potential of about 34 mV. The PEI-oleic acid micelles-stabilized palladium nanoparticles (PO-PdNPsn) were prepared by the reduction of sodium tetrachloropalladate using NaBH4 and the palladium nanoparticles (PdNPs) were anchored in the hydrophilic layer of the micelles. The prepared PO-PdNPsn had a small size for PdNPs and good stability in solution. Noteworthily, PO-PdNPs150 had the highest catalytic activity in reducing 4-nitrophenol (4-NP) (Knor = 18.53 s−1mM−1) and oxidizing morin (Knor = 143.57 s−1M−1) in aqueous solution than other previous catalysts. The enhanced property was attributed to the improving the stability of PdNPs by PEI-oleic acid micelles. The method described in this report has great potential to prepare many kinds of stable noble metal nanoparticles for treating aqueous pollution.


2021 ◽  
Vol 21 (5) ◽  
pp. 3107-3114
Author(s):  
Zhuo-Rui Li ◽  
Geng Zhu ◽  
Guo-Zhi Han

We firstly discover the enhanced catalytic activity of magnetic noble metal nanoparticles mediated by surface plasmon resonance. Under light irradiation with certain wavelength, the catalytic performance of magnetic noble metal nanoparticles shows changes with different degrees and directions that are associated with the surface plasmon resonance (SPR) of the noble metal. Moreover, the coupling of silver and gold allows the catalytic performance of magnetic bimetallic Ag–Au nanoparticles to show more positive response to surface plasmon resonance. The magnetic bimetallic Ag–Au nanoparticles show excellent catalytic performance toward the reduction reaction of aromatic nitro group, and corresponding rate constant of the catalytic reduction reaction increases about three times with light irradiation.


2020 ◽  
Vol 8 (34) ◽  
pp. 7801-7811 ◽  
Author(s):  
Yang Ling ◽  
Tiantian Cao ◽  
Libin Liu ◽  
Jingli Xu ◽  
Jing Zheng ◽  
...  

Herein, we present a facile strategy to fabricate noble metal (Ag, Au, Pd) decorated on PPy@MoS2 microtubes. As a proof of application, the ternary PPy@MoS2@Au hybrids reveal excellent enzyme-like catalytic performance.


2015 ◽  
Vol 2 (6) ◽  
pp. 606-612 ◽  
Author(s):  
Yu-Zhen Chen ◽  
Linfeng Liang ◽  
Qihao Yang ◽  
Maochun Hong ◽  
Qiang Xu ◽  
...  

A novel noble metal-seed-mediated approach to reduce non-noble metals under mild conditions to afford non-noble metal NPs with superior catalytic performance.


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