TY  - JOUR
A1  - Zhao, Yuhang
A1  - Sarhan, Radwan Mohamed
A1  - Eljarrat, Alberto
A1  - Kochovski, Zdravko
A1  - Koch, Christoph
A1  - Schmidt, Bernd
A1  - Koopman, Wouter-Willem Adriaan
A1  - Lu, Yan
T1  - Surface-functionalized Au-Pd nanorods with enhanced photothermal conversion and catalytic performance
T2  - ACS applied materials & interfaces
N2  - Bimetallic nanostructures comprising plasmonic and catalytic components have recently emerged as a promising approach to generate a new type of photo-enhanced nanoreactors. Most designs however concentrate on plasmon-induced charge separation, leaving photo-generated heat as a side product. 
This work presents a photoreactor based on Au-Pd nanorods with an optimized photothermal conversion, which aims to effectively utilize the photo-generated heat to increase the rate of Pd-catalyzed reactions. Dumbbell-shaped Au nanorods were fabricated via a seed-mediated growth method using binary surfactants. Pd clusters were selectively grown at the tips of the Au nanorods, using the zeta potential as a new synthetic parameter to indicate the surfactant remaining on the nanorod surface. 
The photothermal conversion of the Au-Pd nanorods was improved with a thin layer of polydopamine (PDA) or TiO2. 
As a result, a 60% higher temperature increment of the dispersion compared to that for bare Au rods at the same light intensity and particle density could be achieved. 
The catalytic performance of the coated particles was then tested using the reduction of 4-nitrophenol as the model reaction. Under light, the PDA-coated Au-Pd nanorods exhibited an improved catalytic activity, increasing the reaction rate by a factor 3. 
An analysis of the activation energy confirmed the photoheating effect to be the dominant mechanism accelerating the reaction. Thus, the increased photothermal heating is responsible for the reaction acceleration. 
Interestingly, the same analysis shows a roughly 10% higher reaction rate for particles under illumination compared to under dark heating, possibly implying a crucial role of localized heat gradients at the particle surface. 
Finally, the coating thickness was identified as an essential parameter determining the photothermal conversion efficiency and the reaction acceleration.
KW  - Au-Pd nanorods
KW  - PDA
KW  - photothermal conversion
KW  - surface plasmon
KW  - 4-nitrophenol
Y1  - 2022
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/63100
SN  - 1944-8244
SN  - 1944-8252
VL  - 14
IS  - 15
SP  - 17259
EP  - 17272
PB  - American Chemical Society
CY  - Washington, DC
ER  -