0000000000964700
AUTHOR
Hermenegildo García Gómez
showing 4 related works from this author
Exploring the catalytic performance of a series of bimetallic MIL-100(Fe, Ni) MOFs
2019
[EN] A series of mixed-metal Fe-III/Ni-II metal-organic frameworks (MOFs) of the MIL-100 type containing different metal ratios have been synthesized de novo, following an approach that requires tuning of the Fe-III/Ni-II reactivity. The resulting heterometallic MIL-100(Fe, Ni) materials maintain thermal, chemical and structural stability with respect to the parent MIL-100(Fe) MOF as can be deduced from various techniques. The nature and the oxidation state of the accessible metal cations have been evaluated by in situ infrared spectroscopy and extended X-ray absorption fine structure measurements. The obtained mixed-metal MOFs and the parent material have been evaluated as heterogeneous ca…
Perylenetetracarboxylic anhydride as a precursor of fluorescent carbon nanoonion rings
2015
[EN] Thermal annealing at 400 degrees C of perylenetetracarboxylic anhydride in low molecular mass PEG gives rise to the formation of well defined nanoobjects of 2.5 nm height and size distribution from 10 to 65 nm (average 40 nm) after purification of the raw mixture with silicagel chromatography. TEM reveals that the flat nanoobjects are constituted of concentric graphenic rings (0.34 nm interlayer distance). The morphology of the nanoparticles resembles onion rings of nanometric dimensions (nanoonion rings C-NOR). C-NOR particles have an excitation dependent emission with lambda(em) from 430 to 570 nm and a maximum emission quantum yield of 0.49. C-NOR particles can be internalized into …
Increased photocatalytic activity and selectivity towards methane of trimetallic NiTiAl-LDH
2022
Layered double hydroxides is a rising family of materials with interesting photocatalytic properties that are starting to be employed on the CO photoreduction to useful chemicals. However, the selectivity control towards high energy value products, such as methane or methanol, is one of the main issues of this process due to the easier formation of CO, which requires fewer electrons to be transferred, and the competition of hydrogen evolution reaction. In this work, a new LDH material containing Ni, Ti and Al within the structure was synthesised with the purpose of increasing the selectivity towards methane production. The material was tested under solar simulator conditions, yielding a met…
The synthesis of a hybrid graphene-nickel/manganese mixed oxide and its performance in lithium-ion batteries
2012
[EN] Mixing of aqueous suspensions of delaminated NiMn layered double hydroxide (LDH) and graphene oxide leads to the instantaneous precipitation of a hybrid material that after calcination under inert atmosphere at 450 degrees C leads to Ni6MnO8 nanoparticles deposited on larger reconstituted graphene sheets. This material exhibits electrical conductivity similar to graphite, superparamagnetism and can be used as an anode for Li-ion batteries. A maximum capacity value of 1030 mAh g(-1) was found during the first discharge, and capacity values higher than 400 mAh g(-1) were still achieved after 10 cycles. The methodology used here should allow the preparation of a large variety of hybrid gr…