pH‐Triggered Recovery of Organic Polymer Photocatalytic Particles for the Production of High Value Compounds and Enhanced Recyclability

Abstract

Pseudo-homogeneous polymeric photocatalysts are an emerging class of highly efficient and tunable photocatalytic materials, where the photocatalytic centers are easily accessible. The creation of highly efficient photocatalytic materials that can be rapidly separated and recovered is one of the critical challenges in photocatalytic chemistry. Here, we describe pHresponsive photocatalytic nanoparticles that are active and well-dispersed under acidic conditions but aggregate instantly upon elevation of pH, enabling easy recovery. These responsive photocatalytic polymers can be used in various photocatalytic transformations, including Cr VI reduction and photoredox alkylation of indole derivative. Notably, the cationic nature of the photocatalyst accelerates reaction rate of an anionic substrate compared to uncharged species. These photocatalytic particles could be readily recycled allowing multiple successive photocatalytic reactions with no clear loss in activity.

Evaluation of Nanoparticles Covalently Bound with BODIPY for Their Photodynamic Therapy Applicability

“…Thw water compatibility and stability of the PS BOD-I 2 have been significantly enhanced by incorporating molecular BOD-I 2 into the PDHPMA block. Changes in pH within the range of 4-10 do not determine morphological or stability alterations of the NPs tested, as previously reported [25].…”

Recent advances in porous molecular cages for photocatalytic organic conversions

“…129 The metal nanoparticles, however, exhibit thermal instability and are prone to migration and coalescence during the catalytic process due to their high surface energy. Encapsulating metal nanoparticles in nano-shells or nano-pores, such as organometallic frameworks (MOFs), [130][131][132][133] covalent organic frameworks (COFs), 134 organic molecular cages, 75,[135][136][137] and amorphous porous organic polymers (POPs), [138][139][140] is expected to prevent the migration and coalescence of NPs, thereby improving their catalytic stability. 141 POC is a potential candidate for synthesizing and stabilizing NPs due to its unique spatial constraint effect.…”

Heterogeneous Photocatalysts for Light‐Mediated Reversible Deactivation Radical Polymerization

“…Many of these alternatives leverage selective or reduced solubility in the reaction medium. For example, “pseudo‐homogeneous” polymeric photocatalysts contain regions which are partially soluble and can help with separation by solvent extraction [190,220,221] . A pseudo‐homogeneous copolymer nanogel was produced by Ferguson and co‐workers [222] .…”

“…For example, "pseudo-homogeneous" polymeric photocatalysts contain regions which are partially soluble and can help with separation by solvent extraction. [190,220,221] A pseudo-homogeneous copolymer nanogel was produced by Ferguson and co-workers. [222] A photocatalyst monomer was copolymerized with N-isopropyl acrylamide and the resulting photocatalytic networks were studied for photocatalytic degradations, oxidation of styrene, and the formation of disulfide bridges.…”