A novel Bi4Ti3O12/Ag3PO4 heterojunction photocatalyst with enhanced photocatalytic performance

Abstract

In this work, we integrated Ag3PO4 with Bi4Ti3O12 to form Bi4Ti3O12/Ag3PO4 heterojunction nanocomposites by an ion-exchange method. The as-prepared Bi4Ti3O12/Ag3PO4 composites were systematically characterized by means of XRD, SEM, TEM, BET, XPS, UV-vis DRS, EIS, PL spectroscopy, and photocurrent response. SEM, TEM, and XPS results demonstrate the creation of Bi4Ti3O12/Ag3PO4 heterojunction with obvious interfacial interaction between Bi4Ti3O12 and Ag3PO4. PL spectra, EIS spectra, and photocurrent responses reveal that the composites display an enhanced separation efficiency of photogenerated electron-hole pairs, which is due to the charge transfer between Bi4Ti3O12 and Ag3PO4. Rhodamine B (RhB) was chosen as the target organic pollutant to evaluate its degradation behavior over Bi4Ti3O12/Ag3PO4 composites under simulated sunlight irradiation. Compared to bare Bi4Ti3O12 and Ag3PO4 nanoparticles, the composites exhibit a significantly enhanced photocatalytic activity. The highest photocatalytic activity is observed for the 10% Bi4Ti3O12/Ag3PO4 composite with 10% Bi4Ti3O12 content, which is about 2.6 times higher than that of bare Ag3PO4. The photocatalytic mechanism involved was investigated and discussed in detail.

Enhanced Photocatalytic Degradation Activity of BiFeO3 Microspheres by Decoration with g-C3N4 Nanoparticles

“…It is well known that the photogenerated holes in the VB of g-C 3 N 4 possess strong ability to oxidize dyes directly. However, because the VB potential of g-C 3 N 4 is negative to the redox potentials of H 2 (5)). The analysis result confirms the role of H 2 O 2 for the dye degradation.…”

“…(1) (2) In the above equation, the X and E e are the absolute electronegativity of materials (defined as the arithmetic mean of the electron affinity and the first ionization of the constituent atoms) and energy of free electrons on the hydrogen scale (~ 4.5 eV), respectively. The X value of BiFeO 3 is calculated to be 5.93 eV based on the data reported in literatures 34,35 , and the X value for g-C 3 N 4 nanoparticles is reported to be 4.72 eV 36 .…”

“…Therefore, many strategies have been employed to suppress the recombination of photoinduced charges [13][14][15][16][17][18][19] . Among these methods, coupling BiFeO 3 with narrow-bandgap semiconductor of suitable band potential including BiVO 4 , Ag/AgCl, Fe 2 O 3 and Bi 2 Fe 4 O 9 is demonstrated to be an efficient way to promote photogenerated charges migration and separation, and then improve its photocatalytic activity [16][17][18][19] .…”

“…Semiconductor based photocatalysis has attracted considerable attentions owing to its promising application in solar energy conversion and environmental purification [1][2][3][4][5][6] . Perovskite oxide has been proven to be an important class of photocatalysts 7 .…”

Facile Synthesis and Enhanced Visible-Light Photocatalytic Activity of Novel p-Ag3PO4/n-BiFeO3 Heterojunction Composites for Dye Degradation

“…In most cases, owing to its appropriate energy band position and narrow bandgap, Ag 3 PO 4 is widely employed as the cocatalyst to combine with other photocatalysts to form composites, leading to an obvious improvement of photocatalytic behavior, such as Ag 3 PO 4 /Bi 2 WO 6 , Ag 3 PO 4 /BiPO 4 , Ag 3 PO 4 /Bi 2 O 2 CO 3 , Ag 3 PO 4 /g-C 3 N 4 , Ag 3 PO 4 /BiVO 4 , Bi 4 Ti 3 O 12 /Ag 3 PO 4 , Ag 3 PO 4 /ZnFe 2 O 4 , Ag 3 PO 4 /WO 3 , Ag 3 PO 4 /ZnO, and Bi 2 MoO 6 /Ag 3 PO 4 [38–47]. It is reported that BiFeO 3 is an n-type semiconductor and Ag 3 PO 4 is known as a p-type semiconductor [43, 48]. The construction of Ag 3 PO 4 /BiFeO 3 p-n heterojunction composites may be a feasible method to obtain efficient photocatalyst.…”