Synthesis and Optical Properties of Ag(I), Pb(II), and Bi(III) Tantalate-Based Photocatalysts

Abstract

The Ag(I) and Bi(III) tantalates

Structural and electronic investigations of PbTa4O11 and BiTa7O19 constructed from α-U3O8 types of layers

“…[25][26][27][28] Previous investigations of the optical properties and the photocatalytic activities of the ternary tantalates within this structural family by the Maggard group have included the fluxprepared Na 2 Ta phases showed reduced bandgap sizes and significant enhancement in the water reduction and oxidation photocatalytic activities. 1,11 For example, the lowest-energy band gap transitions were found to be red-shifted in comparison to Na 2 Ta 4 O 11 . Photocatalytic hydrogen and oxygen production rates for the lead-exchanged PbTa 4 O 11 were found to be higher than the precursors Na 2 Ta 4 O 11 and Ag 2 Ta 4 O 11 .…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14] Structures in this family are based on the stacking of Į-U 3 O 8 type of pentagonal bipyramidal NbO 7 or TaO 7 layers, where n defines the average thickness (1 2 n ≤ ≤ ) of the BO 7 layers. [1][2][3][4][5][6][7][8][9][10]13,16,18,19,22 The many previously reported ternary phases are a result of the diverse range of A-site metal cations (e.g., Na, Ag, Cu, Pb, La, Bi, Ce, etc.) that occupy the interlayer sites, which includes 2-, 6-, 7-, and 8-coordinate sites.…”

“…1,3,[5][6][7][8][9][10][11][12][13][14][15][17][18][19][20][21][22][23][24] New phases within this structural family can be prepared with the aid of a molten metal-halide flux, such as through enabling the low temperature stabilization of new compositions (e.g., Cu 2 Ta 4 O 11 ), 5 or in the utilization of intermediate phases for ion-exchange reactions (e.g., PbTa 4 O 11 ). 1 Molten fluxes also act to kinetically stabilize new phases that cannot be directly synthesized using traditional solid-state methods. 25 Flux-mediated exchange reactions utilize pre-synthesized metal oxides with a desired parent structure that are reacted within a low-temperature molten-salt flux.…”

“…Both PbTa 4 O 11 and BiTa 7 O 19 exhibited photocatalytic activities for total water splitting under irradiation by visible and ultraviolet light. 1 However, in-depth structure-property relationships are limited by the absence of a refined crystal structure for PbTa 4 O 11 , and by the presence of Bi/Ta-site disorder reported for BiTa 7 O 19 . Full structural refinements were investigated for both the BiTa 7 O 19 and the PbTa 4 O 11 phases, and showing symmetry-lowered structures in comparison to the previous initial reports.…”

Construction of novel ternary component photocatalyst Sr0.25H1.5Ta2O6·H2O coupled with g-C3N4 and Ag toward efficient visible light photocatalytic activity for environmental remediation

“…Various semiconductors including oxide, sulfide, and oxynitride have been developed for environmental purification. Among them, nano-sized tantalate-based photocatalysts have been extensively investigated due to their excellent photophysical and photochemical properties [4][5][6][7]. However, the limited utilization of solar energy and the low separation efficiency of photogenerated electrons and holes result in low visible light photocatalytic activity.…”