CdS aerogels as efficient photocatalysts for degradation of organic dyes under visible light irradiation

Abstract

Synthesis of efficient photocatalysts based on CdS nanomaterials for oxidative decomposition of organic effluents typically focuses on (a) enhancement of surface area of the catalysts and (b) promotion of the separation of photogenerated electron-hole pairs. CdS aerogel, which are synthesized by simple sol–gel assembly of discrete nanocrystals (NCs) into a porous network followed by supercritical drying, could provide higher surface area for photocatalytic reactions along with facile charge separation due to direct contact between NCs via covalent bonding. We evaluated the efficiency of CdS aerogel materials for degradation of organic dyes using methylene blue (MB) and methyl orange (MO) as test cases. CdS aerogel materials exhibited remarkable photocatalytic activity for dye degradation compared to typical, ligand-capped CdS NCs. The catalytic efficiency of CdS aerogels was further improved by decreasing the chain-length and extent of surface organics, leading to higher, and more hydrophilic, accessible surface area. The use of porous, chalcogenide-based solid state architectures for photocatalysis enables easy separation of catalyst while ensuring a high-interfacial surface area for analyte reactivity and visible light activation.

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

“…electrocatalysis, 26,27 photoelectrochemical applications, 6,28 and photocatalysis. 1,3,29 In the recent past, different working groups investigated cation exchange reactions on nanocrystals with different shapes and material composition. [30][31][32][33][34][35] Due to the short diffusion path of the cations within the nanoparticle crystal, even cation exchange reactions which are unknown (or extremely slow) on the bulk scale can occur.…”

Patterning of Nanoparticle‐Based Aerogels and Xerogels by Inkjet Printing

“…Since the development of nanoparticle based aerogel structures, there is a high interest in these self‐assembled 3D nanoparticle networks and in exploiting their suitability in different fields, e.g. photocatalysis, electrocatalysis, and photo‐electrochemical application like sensing . By controlling the destabilization process of the nanocrystals, it is possible to obtain nanoparticle networks in which the nanoparticles are connected to each other in a defined way .…”

Versatile route to core–shell reinforced network nanostructures

“…19 Similarly semiconductor nanoparticle based networks were employed as photocatalysts. 20 Our group recently demonstrated a semiconductor network based sensor also showing the higher sensitivity of the network compared to plain nanoparticles. 21 One drawback of the monolithic network structures is their poor mechanical stability which is widely regarded as the point inhibiting application of these networks.…”