Two Tungstates Containing Platinum Nanoparticles Prepared by Air-Calcining Keggin-Type Polyoxotungstate-Coordinated Diplatinum(II) Complexes: Effect on Sintering-Resistance and Photocatalysis

Abstract Two tungstates containing platinum nanoparticles (Pt Npts) were obtained by air-calcining α-Keggin-type diplatinum(II)-coordinated polyoxotungstates, Cs 3 [α-PW 11 O 39 { cis -Pt(NH ) 2 } ]⋅8H ( Cs-P-Pt and 4 [α-SiW ]⋅11H Cs-Si-Pt ), at 700–900 °C for 5 h. The polyoxotungstate was transformed to a mixture of Pt Npts PW 12 40 upon calcination, while the structures W 35 . generated 700 h uniform with an average particle size 3.6 ± 1.1 nm, which much smaller than that calcining (19.9 9.9 nm) under identical conditions. This demonstrated significant inhibitory effect on aggregation during high-temperature air-calcination high content (10.6 wt.%) in absence support. During calcination °C, exhibited higher activities respect hydrogen evolution from aqueous triethanolamine solutions visible light irradiation presence Eosin Y, mono-aluminum-substituted polyoxotungstate, titanium dioxide. When calcined 800 100 h, no decrease activity observed comparison Graphical