Direct synthesis of single-walled aminoaluminosilicate nanotubes with enhanced molecular adsorption selectivity

Chemically Selective Alternatives to Photoferroelectrics for Polarization‐Enhanced Photocatalysis: The Untapped Potential of Hybrid Inorganic Nanotubes

“…Confinement of reactants and intermediates inside nanoporous PCs has also started to be explored and observed to benefit reaction selectivity 3. To foster optimized integration of these currently disconnected research strategies into chemically selective alternatives to photoferroelectrics for polarization‐enhanced photocatalysis, here we investigate an emerging class of cheap 1D nanomaterials, namely, hybrid inorganic–organic imogolite nanotubes (Imo‐NTs) 6. Linear‐scaling density functional theory (DFT) simulations elucidate the interplay between NT functionalization, curvature, permanent polarization, band gap (BG), band‐separation, band‐alignment, and charge‐transfer excitations, enabling informed design of a novel class of locally polarized, selective porous PCs.…”

“…Progress has also been made in the post‐synthetic selective functionalization of the outer or inner surface of AlSi NTs,10 and in the synthesis of hybrid organic–inorganic methylated (AlSi‐Me) or aminated AlSi NTs derivatives, that have —CH 3 ( Figure 1 a) and —CH 2 —NH 2 groups in the NT cavity 6. Synthesis of hybrid methylated Al(Si/Ge)‐Me NTs with a tunable Si/Ge ratio has also been reported.…”

“…Synthesis of hybrid methylated Al(Si/Ge)‐Me NTs with a tunable Si/Ge ratio has also been reported. [[qv: 6c]] The occurrence of a hydrophobic cavity inside an otherwise hydrophilic NT leads to superior chemical separation performances,6, 10 defining a potentially advantageous starting point for the integration of chemical separation and photocatalytic strategies in this class of porous 1D material.…”

“…To explore the occurrence of optically active charge‐transfer excitations across the NT‐wall, we next simulate the optical spectra for the AlSi N ‐Me systems ( N = 28 and 34) bracketing the experimental pore‐size distribution 6. Notably, optical transitions involving states at the VBE and CBE on different sides of the NT‐cavity (Figure 2a) are found to contribute strongly to the low‐energy absorbance peak (Figure 2c), suggesting the occurrence of charge‐transfer excitations across the NT‐walls.…”

“…These excitations and the prospective enhancement to e–h separation (the NT‐wall thickness is roughly 11 Å) may be beneficial to sustain photocatalytic reactivity. Such benefits should be larger for homogenous photocatalysis applications, with the soluble6 NTs dispersed in the same medium as the reactants, rather than deposited on a photo‐electrode. Provided no e (h) diffusion along the NT is needed by the photoreduction (oxidation) event, the NTs' relatively large effective electron (m e ) and hole (m h ) masses (m e : 0.79–0.81 m 0 , m h : 5.77–7.41 m 0 , Figures S19 and S20 and Table S9, Supporting Information) and expected low photoconductivity may not be a limitation.…”