Emerging switchable ultraviolet photoluminescence in dehydrated Zn/Al layered double hydroxide nanoplatelets

Abstract

Layered double hydroxides show intriguing physical and chemical properties arising by their intrinsic self-assembled stacking of molecular-thick 2D nanosheets, enhanced active surface area, hosting of guest species by intercalation and anion exchanging capabilities. Here, we report on the unprecedented emerging intense ultraviolet photoluminescence in Zn/Al layered double hydroxide high-aspect-ratio nanoplatelets, which we discovered to be fully activated by drying under vacuum condition and thermal desorption as well. Photoluminescence and its quenching were reproducibly switched by a dehydration–hydration process. Photoluminescence properties were comprehensively evaluated, such as temperature dependence of photoluminescence features and lifetime measurements. The role of 2D morphology and arrangement of hydroxide layers was demonstrated by evaluating the photoluminescence before and after exfoliation of a bulk phase synthetized by a coprecipitation method.

Layered Double Hydroxides in Bioinspired Nanotechnology

“…interlayer spacing, in accord with our experimental findings [37], favoring both the crowing of amino acids and the alignment of the N-and C-termini, and also permitting the formation of a peptide bond (see Figure 5). This reaction leads to the loss of charged group, which, in turn, allows for the introduction of a new amino acid to an adjacent site, where it then can react with the peptide's Cterminus.…”

“…Intriguingly, all the amino acids they investigated (alanine, aspartate, histidine, leucine, lysine and tyrosine) showed an increase in adsorption upon dehydration, with the only exception of lysine. Dehydration, in turn, decreases the interlayer spacing, in accord with our experimental findings [37], favoring both the crowing of amino acids and the alignment of the N-and C-termini, and also permitting the formation of a peptide bond (see Figure 5). This reaction leads to the loss of charged group, which, in turn, allows for the introduction of a new amino acid to an adjacent site, where it then can react with the peptide's C-terminus.…”

“…In the last years, with the aim to increase LDH dispersion and organophilicity and to fabricate stable delaminated LDH dry powders, O'Hare and coworkers developed post-treatment routes for LDHs using both aqueous miscible organic (AMO-LDHs) and aqueous immiscible (AIM-LDHs) organic solvents, yielding highly porous, highly dispersed LDH powders of exfoliated nanosheets [33,34]. Some experimental protocols also permit films of interconnected LDH nanoplatelets to be grown onto aluminum surfaces as hierarchically nanostructured coatings by soaking aluminum thick foils in an aqueous solution containing a soluble zinc salt [35][36][37][38][39]. In this case, the trivalent ions (Al 3+ ) are provided by the sacrificial aluminum foil, whose role is both reactant and substrate, and ultimately allows the LDH film adhesion to be improved.…”

Printing ZnO Inks: From Principles to Devices

“…in a paper by some of the present authors [80]. In a previous work, our group reported on a wetchemistry fabrication method of ZnO NWs conceived by means of a rational design [81][82][83].…”

Layered double alkoxides a novel group of layered double hydroxides without water content

“…Furthermore, water-free ZnAl films have photoluminescence property [27]. Moreover, having high surface area with notable porosity, the alcohol-treated systems were found to be better absorbent than pure LDH [28].…”