Study of n- alkylamine Intercalated Layered Perovskite-Like Niobates HCa2Nb3O10 as Photocatalysts for Hydrogen Production From an Aqueous Solution of Methanol

Vladimir V Voytovich; Sergei A Kurnosenko; Oleg I Silyukov; Ivan A Rodionov; Iana A Minich; Irina A Zvereva

doi:10.3389/fchem.2020.00300

Study of n- alkylamine Intercalated Layered Perovskite-Like Niobates HCa₂Nb₃O₁₀ as Photocatalysts for Hydrogen Production From an Aqueous Solution of Methanol

Front Chem. 2020 Apr 23:8:300. doi: 10.3389/fchem.2020.00300. eCollection 2020.

Authors

Vladimir V Voytovich¹, Sergei A Kurnosenko¹, Oleg I Silyukov¹, Ivan A Rodionov¹, Iana A Minich¹, Irina A Zvereva¹

Affiliation

¹ Institute of Chemistry, Saint Petersburg State University, Saint Petersburg, Russia.

Abstract

A series of hybrid niobates HCa₂Nb₃O₁₀×RNH₂, containing n-alkylamines (R = Me, Et, Pr, Bu, Hx, Oc) intercalated into the interlayer space, has been thoroughly studied concerning the photocatalytic hydrogen production from a model aqueous solution of methanol for the first time. All the hybrid photocatalysts were synthesized by the conventional ceramic technique followed by protonation and intercalation of n-alkylamines. The products were characterized using XRD, Raman, IR and diffuse reflectance spectroscopy, TGA, CHN-analysis and SEM. Photocatalytic measurements were conducted according to an advanced scheme taking into account possible changes in the photocatalyst concentration because of sedimentation, pH shifts and exfoliation of the samples into nanoplatelets. Special attention was also paid to the feasible improvement of the photocatalytic activity of the samples via their modification with Pt nanoparticles as a cocatalyst. In the series of amine derivatives, the highest rate of hydrogen generation was demonstrated by the Pt-loaded HCa₂Nb₃O₁₀×BuNH₂ reaching apparent quantum efficiency of 13% in the 220-340 nm range. The initial HCa₂Nb₃O₁₀ showed comparable efficiency of 8.3% that is greater than for other amine derivatives. It was demonstrated that for the investigated samples the photocatalytic activity correlates with their ability of water intercalation.

Keywords: amine; hybrid compounds; hydrogen; intercalation; layered; niobate; perovskite; photocatalysis.