Synthesis and facet-dependent enhanced photocatalytic activity of Bi₂SiO₅/AgI nanoplate photocatalysts

Abstract

Novel Z-scheme Bi2SiO5/AgI nanoplate photocatalysts with the exposure of {100} facets on the surfaces of Bi2SiO5 nanoplates were synthesized via an in situ precipitation method. Acid red G aqueous solution and gaseous formaldehyde were chosen as model organic pollutants to evaluate the photocatalytic activities of the as-prepared catalysts. Under visible light irradiation (>420 nm), the Bi2SiO5/AgI nanoplates exhibited enhanced photocatalytic activities as compared to the pure Bi2SiO5 or AgI. X-ray photoelectron spectroscopy (XPS) reveals that few amount of metallic Ag was formed on the surface of AgI during the photocatalytic reaction, thus leading to the transformation from Bi2SiO5/AgI to Bi2SiO5/AgI@Ag. The excellent photocatalytic activities of the Bi2SiO5/AgI nanoplates can be ascribed to the Z-scheme photocatlytic system composed of Bi2SiO5, AgI and metallic Ag and the inner electric field caused by exposure of {100} facets on the Bi2SiO5 nanoplates. The as-prepared catalysts remained good photocatalytic activity after four recycles and the radical species involved in the degradation process have been investigated by the PL spectra and trapping experiments.

Regulations of silver halide nanostructure and composites on photocatalysis

“…Besides providing these organic matter references, some representative parameters for photocatalysis evaluation have also been summarized and analyzed, such as the apparent rate constant (k app ) and total organic carbon (TOC). [240] benzene Ag/AgCl/TiO 2 /PM [289] acridine orange (AO) Ag@AgX (X = Cl, Br) [308] acid red G aqueous solution Bi 2 SiO 5 /AgI [268] The real-time concentration changes of organic pollutants during photocatalytic degradation are detected through their UV-visible absorbance. According to Lambert-Beer law, actual concentration changes of colored dye molecules (C/C 0 ) are directly proportional to their corresponding normalized UVvis absorption values (A/A 0 ).…”

“…Heterogeneous system constituted by photoactive semiconductors is regarded as an effective method to facilitate the photoexcited electron-hole separation with enhanced photocatalytic activity [254][255][256][257][258][259][260][261][262][263][264][265][266][267][268][269]. Various metallic semiconductor (such as TiO 2 , ZnO, BiVO 4 ) and metal-free nitrogen-doped graphene semiconductors have been considered as preferred substances to composite with AgX, shown as Table 2.…”

Potassium Tantalate K6Ta10.8O30 with Tungsten Bronze Structure and Its Photocatalytic Property

“…[46,47] The photocatalytic activity of the photocatalyst is related to its structure. [48][49][50][51][52][53][54] Also, the higher photocatalytic activity of K 6 Ta 10.8 O 30 against ARG may be in connection with the TaO 6 octahedrons in the crystal structures and K ＋ in pentagonal tunnels. The highly distorted surface TaO 6 octahedral sites like NbO 6 might facilitate the movement of photogenerated electron-hole pairs, inhibit the recombination of elec-tron-hole pairs and finally increase the catalytic activity of the K 6 Ta 10.8 O 30 catalyst for ARG decomposition.…”

Enhancing photocatalytic performance of BiOX for Bisphenol – A degradation

“…[18][19] Bismuth oxyhalides were implemented in dyes photodegradation like Rhodamine B, [16] methyl orange, [17] BF dye, [15] orangeII, ARG, and Azure B. [18][19][20] BiOXs have also been applied in organic removal, disinfection and heavy metal reduction from water such as Chromium (VI). [13][14][21][22][23] The studies have demonstrated that they have high performance under visible light.…”