Multimodal Analysis of Light‐Driven Water Oxidation in Nanoporous Block Copolymer Membranes**

Abstract

Heterogeneous light-driven catalysis is a cornerstone of sustainable energy conversion. Most catalytic studies focus on bulk analyses of the hydrogen and oxygen evolved, which impede the correlation of matrix heterogeneities, molecular features, and bulk reactivity. Here, we report studies of a heterogenized catalyst/photosensitizer system using a polyoxometalate water oxidation catalyst and a model, molecular photosensitizer that were co-immobilized within a nanoporous block copolymer membrane. Via operando scanning electrochemical microscopy (SECM), light-induced oxygen evolution was determined using sodium peroxodisulfate (Na 2 S 2 O 8 ) as sacrificial electron acceptor. Ex situ element analyses provided spatially resolved information on the local concentration and distribution of the molecular components. Infrared attenuated total reflection (IR-ATR) studies of the modified membranes showed no degradation of the water oxidation catalyst under the reported light-driven conditions.

Polyoxometalate-Modified Amphiphilic Polystyrene-block-poly(2-(dimethylamino)ethyl methacrylate) Membranes for Heterogeneous Glucose to Formic Acid Methyl Ester Oxidation

“…Further, we also demonstrated the successful covalent attachment of the Ru-based PS to the membrane made of poly(styrene- co -isoprene)- block -poly((4-vinylbenzyl chloride)- co -(tri(ethylene glycol) methyl ester acrylate)) (P(S- co -I)- b -P(VBCl- co -TEGA)) [ 16 ]. In our latest work, we successfully applied the PS- b -PDMAEMA membrane modified with electrostatically attached [Ru(bpy) 3 ] 2+ PS and polyoxometalate cluster [Co 4 (H 2 O) 2 -(PW 9 O 34 ) 2 ] 10− catalyst (POW-WOC) for water oxidation catalysis [ 17 ].…”

Self-Assembly of Polyoxometalate-Based Nanoparticle Surfactants in Solutions

“…Polyoxometalates (POMs) are a large family of negatively charged metal-oxo clusters with distinct metal compositions and structures, possessing various composition-dependent properties, such as high thermal stability, tunable acidity, and magnetic and redox properties. − By modifying POM with organic compounds, a series of amphiphilic POM–organic hybrids were synthesized and have become a rising category of giant surfactant, whose supramolecular organization and self-assembly have been attracting great interest and been shown to be promising in catalysis, photochemistry, electrochemistry, and biochemistry. − Here, we present a study on the solution assembly of a newly developed organic–inorganic hybrid NPS, POM-based surfactants (POMSs). By mixing the aqueous solution containing β-cyclodextrin (β-CD) grafted Anderson-type polyoxometalate clusters and tetrahydrofuran (THF) solution dissolving ferrocene-terminated polystyrene (Fc-PS), POMSs were formed via host–guest interactions and assembled to aggregates driven by a solvent-phobic effect, where the self-organization of POMSs strongly depends on the solvent polarity (Scheme ).…”