TY  - GEN
A1  - El-Nagar, Gumaa A.
A1  - Lauermann, Iver
A1  - Sarhan, Radwan Mohamed
A1  - Roth, Christina
T1  - Hierarchically structured iron-doped silver (Ag-Fe) lotus flowers for an efficient oxygen reduction reaction (vol 10, pg 7304 -7310, 2018)
T2  - Nanoscale
Y1  - 2019
U6  - https://doi.org/10.1039/c9nr90131k
SN  - 2040-3364
SN  - 2040-3372
VL  - 11
IS  - 24
SP  - 11975
EP  - 11975
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Sarhan, Radwan Mohamed
A1  - El-Nagar, Gumaa A.
A1  - Abouserie, Ahed
A1  - Roth, Christina
T1  - Silver-Iron Hierarchical Microflowers for Highly Efficient H2O2 Nonenzymatic Amperometric Detection
JF  - ACS sustainable chemistry & engineering
N2  - This study addresses the fabrication of monodispersed iron-doped silver meso-hierarchical flower-like structures via a facile chemical procedure. The morphology of the obtained silver particles has been tuned by changing the concentration of the structure-directing agent (malonic acid). Ball-shaped silver particles were formed in the absence of malonic acid (MA), while silver particles with craspedia-globosa, chrysanthemum, and dahlia flower-like structures were obtained in the presence of 0.2, 0.5, and 1 mM malonic acid, respectively. The doping of these dahlia flower-like structures with trace amounts of iron (<= 5% Fe weight percent) led to the formation of globe-amaranth iron-doped microflowers (AgFeamaranth). The as-prepared AgFeamaranth exhibited better performance as a nonenzymatic H2O2 sensor compared to undoped silver particles as demonstrated by their higher catalytic activity and stability together with superior sensitivity (1350 mu M-1 cm(-2), 61 times higher) and lower detection limit (0.1 mu M). These enhancements are attributed to the AgFe unique flower-like structures and to the fact that the iron dopants provide a higher number of electroactive sites and reduce the charge transfer resistance of H2O2 reduction. Additionally, the good stability of AgFe is believed to originate from the faster detachment rate of the in situ-formed gas bubbles from their surfaces compared to undoped silver structures.
KW  - Nonenzymatic
KW  - H2O2
KW  - Electrosensing
KW  - Nanostructures
KW  - Iron/silver microflowers
Y1  - 2019
U6  - https://doi.org/10.1021/acssuschemeng.8b06182
SN  - 2168-0485
VL  - 7
IS  - 4
SP  - 4335
EP  - 4342
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - El-Nagar, Gumaa A.
A1  - Lauermann, Iver
A1  - Sarhan, Radwan Mohamed
A1  - Roth, Christina
T1  - Hierarchically structured iron-doped silver (Ag-Fe) lotus flowers for an efficient oxygen reduction reaction
JF  - Nanoscale
N2  - The development of cheap and efficient electrocatalysts for the oxygen reduction reaction (ORR) is vital for the immediate commercialization of fuel cells which are still limited by the high cost and low performance of the utilized commercial Pt-based electrodes. As a promising alternative, this study reports on the synthesis of hierarchical iron-doped silver lotus flowers (AgFelotus) by a facile chemical procedure as robust and efficient ORR electrocatalysts. Succinic acid was used as a structure directing agent to tune the morphology of undoped and iron-doped silver particles. In the absence of succinic acid, ball-like silver particles were obtained, while using 2 mM succinic acid led to peony-like flower structures. The doping of silver peony-flowers with iron resulted in lotus-like flower structures with high electrocatalytic activity for ORR together with outstanding tolerance against poisoning with various hydrocarbon (HC) impurities, in situ generated during fuel cell operation, as well as different fuels from anodic crossover. AgFelotus exhibited a superior ORR activity with more than 40 times higher stability than the commercial Pt/C catalyst in alkaline media. This substantial performance enhancement is attributed to the unique lotus-like flower structures providing more electroactive surface sites, in addition to the iron dopants which facilitate ORR charge transfer.
Y1  - 2018
U6  - https://doi.org/10.1039/c8nr00020d
SN  - 2040-3364
SN  - 2040-3372
VL  - 10
IS  - 15
SP  - 7304
EP  - 7310
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - El-Nagar, Gumaa A.
A1  - Sarhan, Radwan Mohamed
A1  - Abouserie, Ahed
A1  - Maticiuc, Natalia
A1  - Bargheer, Matias
A1  - Lauermann, Iver
A1  - Roth, Christina
T1  - Efficient 3D-Silver Flower-like Microstructures for Non-Enzymatic Hydrogen Peroxide (H2O2) Amperometric Detection
JF  - Scientific reports
Y1  - 2017
U6  - https://doi.org/10.1038/s41598-017-11965-9
SN  - 2045-2322
VL  - 7
PB  - Nature Publ. Group
CY  - London
ER  -