In situ and ex situ functionalization of nanostructured gallium oxy‐hydroxide with a porphyrin dye

Abstract

The surface attachment of a porphyrin dye to nanocrystalline GaOOH was performed using two routes of solution-based functionalization. The first method of functionalization utilized an in situ incorporation of dissolved porphyrin salt in solution during the microwave synthesis step. Additionally, synthesized GaOOH nanorods were mixed in porphyrin solution after the microwave process to make an ex situ GaOOH/TTP-PO- . X-ray photoelectron spectroscopy confirmed the presence of expected surface species and provided evidence of increased surface coverage of TTP-PO on GaOOH in the ex situ- GaOOH/TTP-PO as compared to the in situ one. Size and morphology changes were investigated using SEM and, along with analysis of XRD, the in situ samples showed larger crystallite sizes. This was confirmed with PL due to the higher bandgap energy evident in the ex situ GaOOH/TTP-PO compared to the in situ sample. A stability study was performed using fluorescence spectroscopy which indicated no leaching of porphyrin from the in situ GaOOH/TTP-PO . However, porphyrin leaching was evident from the ex situ GaOOH/TTP-PO sample. The stability of the in situ GaOOH/TTP-PO makes it attractive for a number of interfacial applications. SCANNING 38:671-683, 2016. © 2016 Wiley Periodicals, Inc.

III–VI and IV–VI van der Waals Semiconductors InSe, GaSe and GeSe: A Suitable Platform for Efficient Electrochemical Water Splitting, Photocatalysis and Chemical Sensing

“…After one day of air exposure, a progressive oxidation of the surface with an enhancement of the Ga 2 Se 3 and Ga 2 O 3 components was observed, with a thickness of the oxide layer of ∼0.15 nm. Upon a prolonged exposure of one year in air, an increment of the spectral contribution of Ga 2 O 3 was revealed, with the appearance of a new component associated to mixed oxide‐hydroxide Ga 2 O 3‐x (OH) y species [84–86] . No relevant changes exist in the Se‐3d core level, in which a new component due to Se(0) and the component of Se−Se aggregates [87–89] as byproducts of Ga 2 Se 3 oxidation via 2Ga 2 Se 3 +3O 2 →2Ga 2 O 3 +6Se [74] was found.…”

HgNO3 sensitivity of AlGaN/GaN field effect transistors functionalized with phytochelating peptides

“…18 HNO 3 within the Hg standard solution can also be observed as a nitrate peak (N 1s at 407.5 eV) present in the 1000 ppm and 10 ppm line scans. 24 With regards to the samples used in this study these XPS scans provided qualitative confirmation of the presence of both TAT-C and Phytocelatin-5 peptides before moving into IV characterization of the devices.…”

Nanostructured Oxides Containing Ga: Materials with Unique Properties for Aqueous-Based Applications

“…In the cases of phosphonic acid derivatives, the passivation achieved via the in situ procedure resulted in exceptional ligand stability compared to passivation done ex situ. 22 Water soluble dye molecules with carboxylic acid moieties have been also utilized to modify GaOOH in situ and ex situ. In contrast to other organic acid derivates the ones containing carboxylic acids showed excellent stability in water regardless of what method was used for their preparation.…”