TY  - JOUR
A1  - Mei, Shilin
A1  - Kochovski, Zdravko
A1  - Roa, Rafael
A1  - Gu, Sasa
A1  - Xu, Xiaohui
A1  - Yu, Hongtao
A1  - Dzubiella, Joachim
A1  - Ballauff, Matthias
A1  - Lu, Yan
T1  - Enhanced Catalytic Activity of Gold@Polydopamine Nanoreactors with Multi-compartment Structure Under NIR Irradiation
JF  - Nano-Micro Letters
N2  - Photothermal conversion (PTC) nanostructures have great potential for applications in many fields, and therefore, they have attracted tremendous attention. However, the construction of a PTC nanoreactor with multi-compartment structure to achieve the combination of unique chemical properties and structural feature is still challenging due to the synthetic difficulties. Herein, we designed and synthesized a catalytically active, PTC gold (Au)@polydopamine (PDA) nanoreactor driven by infrared irradiation using assembled PS-b-P2VP nanosphere as soft template. The particles exhibit multi-compartment structure which is revealed by 3D electron tomography characterization technique. They feature permeable shells with tunable shell thickness. Full kinetics for the reduction reaction of 4-nitrophenol has been investigated using these particles as nanoreactors and compared with other reported systems. Notably, a remarkable acceleration of the catalytic reaction upon near-infrared irradiation is demonstrated, which reveals for the first time the importance of the synergistic effect of photothermal conversion and complex inner structure to the kinetics of the catalytic reduction. The ease of synthesis and fresh insights into catalysis will promote a new platform for novel nanoreactor studies.
KW  - Gold@polydopamine
KW  - 3D tomography
KW  - Nanoreactor
KW  - Catalysis
KW  - Photothermal conversion
Y1  - 2019
U6  - https://doi.org/10.1007/s40820-019-0314-9
SN  - 2311-6706
SN  - 2150-5551
VL  - 11
IS  - 1
PB  - Shanghai JIAO TONG univ press
CY  - Shanghai
ER  - 
TY  - JOUR
A1  - Gu, Sasa
A1  - Risse, Sebastian
A1  - Lu, Yan
A1  - Ballauff, Matthias
T1  - Mechanism of the oxidation of 3,3′,5,5′-tetramethylbenzidine catalyzed by peroxidase-like Pt nanoparticles immobilized in spherical polyelectrolyte brushes
BT  - a kinetic study
JF  - ChemPhysChem
N2  - Experimental and kinetic modelling studies are presented to investigate the mechanism of 3,3 ',5,5 '-tetramethylbenzidine (TMB) oxidation by hydrogen peroxide (H2O2) catalyzed by peroxidase-like Pt nanoparticles immobilized in spherical polyelectrolyte brushes (SPB-Pt). Due to the high stability of SPB-Pt colloidal, this reaction can be monitored precisely in situ by UV/VIS spectroscopy. The time-dependent concentration of the blue-colored oxidation product of TMB expressed by different kinetic models was used to simulate the experimental data by a genetic fitting algorithm. After falsifying the models with abundant experimental data, it is found that both H2O2 and TMB adsorb on the surface of Pt nanoparticles to react, indicating that the reaction follows the Langmuir-Hinshelwood mechanism. A true rate constant k, characterizing the rate-determining step of the reaction and which is independent on the amount of catalysts used, is obtained for the first time. Furthermore, it is found that the product adsorbes strongly on the surface of nanoparticles, thus inhibiting the reaction. The entire analysis provides a new perspective to study the catalytic mechanism and evaluate the catalytic activity of the peroxidase-like nanoparticles.
KW  - kinetics
KW  - nanoparticles
KW  - reaction mechanisms
KW  - spherical polyelectrolyte
KW  - brushes
KW  - UV
KW  - vis spectroscopy
Y1  - 2019
U6  - https://doi.org/10.1002/cphc.201901087
SN  - 1439-4235
SN  - 1439-7641
VL  - 21
IS  - 5
SP  - 450
EP  - 458
PB  - Wiley-VCH
CY  - Weinheim
ER  -