Reversible cation exchange on macroscopic CdSe/CdS and CdS nanorod based gel networks

Abstract

Nanoparticle-based lyogels or aerogels represent a type of bridge between the macroscopic and nanoscopic world, while these structures are used to demonstrate the feasibility of cation exchange reactions on such macroscopic nanomaterials.

Aerogelation of Polymer-Coated Photoluminescent, Plasmonic, and Magnetic Nanoparticles for Biosensing Applications

“…These differences can be attributed to the (i) anisotropy of the NRs and (ii) the significantly differing densities of the core materials. Nevertheless, the obtained specific surface areas are in agreement with the ones in our previous gel network consisting of CdSe/CdS NRs 10 , 44 and Pt NCs. 8 The aerogels were found to be ultralightweight with densities of 0.04, 0.01, and 0.18 g/cm 3 for NRs, IONs, and NCs, respectively.…”

Interparticle Interaction Matters: Charge Carrier Dynamics in Hybrid Semiconductor–Metal Cryoaerogels

“…In this regard, hydrogels and aerogels of nanoparticles are highly interesting, as they are self-supporting networks only consisting of the nanoscopic building blocks, and since they are at the same time highly voluminous, monolithic, and have enhanced surface accessibility to their hierarchical nanoporous architectures. [2,3,[10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] Nanocrystal hydrogels and aerogels can be prepared via chemical or physical methods. [1][2][3]26] With respect to the design of multicomponent hydrogels and aerogels from noble metal and semiconductor compounds, there have solely been very few reports so far: Hendel et al reported on mixing of CdTe and noble metal nanoparticles resulting in arbitrary distribution of the gold domains in the network.…”

Quantum Dot Assembly Driven by Electrochemically Generated Metal-Ion Crosslinkers

“…Similar gel sizes were observed when similar amounts of Ag + , Zn 2+ , and Co 2+ ions were electrochemically released to the QD dispersion (Table S2), suggesting the ME-gel growth does not show a clear dependence on the valance of the metal ions. The darkened hue of the ME-gel prepared using an Ag electrode is attributed to some degree of cation exchange of CdS QDs with Ag + , which is known to be facile, to produce Ag 2 S. , However, it is not possible to definitively distinguish Ag 2 S in the PXRD patterns of the ME-gel (Figure S14). This is not surprising because peak broadening associated with the small crystallite size makes identification of minor phases challenging, the silver sulfide is likely to be highly defective and poorly crystalline, and there is considerable overlap between the patterns of hexagonal CdS and cubic Ag 2 S.…”