A new 2D layered aluminophosphate |Hada|6[Al6(PO4)8](H2O)11 supported highly uniform Ag nanoparticles for 4-nitrophenol reduction

Abstract

Aluminophosphate with |Hada|₆[Al₆(PO₄)₈](H₂O)₁₁ (denoted as ZHKU-1) of a new two-dimensional (2D) layer has been synthesized by adopting the template of alkylated memantine. The structure of ZHKU-1 was constructed from the alternate connection of AlO₄ and triply bridged PO₄ tetrahedra ([OPO₃]³⁻) with a P/Al ratio of 4 : 3. The inorganic layers are linked and separated by protonated amine molecules and H₂O molecules through extensive H-bonds to give a supervoid of 19.6 Å, containing an AAAA-stacked sequence along the b axis. The open framework of ZHKU-1 has been adapted for encapsulating silver nanoparticles through photodeposition, forming the catalyst Ag@ZHKU-1. The HRTEM images reveal the highly uniform Ag clusters with visually observed sizes of 1.9 nm. Moreover, Ag@ZHKU-1 has shown an efficient conversion of 99.3% within 75 s for the catalytic reduction of 4-nitrophenol. This remarkable catalytic activity of Ag@ZHKU-1 can be attributed to the large exposed surface and confinement effect of the 2D aluminophosphate of ZHKU-1.