Novel heterostructured Bi2S3/BiOI photocatalyst: facile preparation, characterization and visible light photocatalytic performance

Abstract

Novel Bi(2)S(3)/BiOI heterostructures were successfully synthesized through a facile and economical ion exchange method between BiOI and thioacetamide (CH(3)CSNH(2)), and characterized by multiform techniques, such as XRD, Raman, FT-IR, XPS, SEM, TEM, HRTEM, SAED, BET and DRS. The obtained Bi(2)S(3)/BiOI photocatalysts showed excellent photocatalytic performance for decomposing organic dye methyl orange (MO) compared with pure BiOI under visible light irradiation (λ > 420 nm). Among the Bi(2)S(3)/BiOI photocatalysts with different molar percentage of Bi(2)S(3) to initial BiOI (from 2 to 8%), 4% Bi(2)S(3)/BiOI exhibited the highest photocatalytic activity with apparent k(app) of 0.2968 h(-1). Differently, Bi(2)S(3)/BiOI displayed low photocatalytic activity for many colorless organic substrates, such as phenol, 2-chlorophenol, dimethyl phthalate and 5-sulfosalicylic acid. Moreover, the study on the mechanism suggested that the enhanced photocatalytic activity mainly resulted from the role of Bi(2)S(3)-BiOI heterojunctions formed in the Bi(2)S(3)/BiOI, which could lead to efficient separation of photoinduced carriers.

Ultrasonic-assisted synthesis of amorphous Bi2S3 coupled (BiO)2CO3 catalyst with improved visible light-responsive photocatalytic activity

“…It is revealed that in the sample U1.0, U3.0, and U5.0 the Bi 2 S 3 is homogenously dispersed on (BiO) 2 CO 3 as nanoparticles but not a shell, which is different from the case of U7.0. When a shell was formed on the surface of (BiO) 2 CO 3 (U7.0), the transferred electrons from the CB of Bi 2 S 3 to the CB of (BiO) 2 CO 3 would be kept away from the reactants; furthermore, the accumulation of electrons in the CB of (BiO) 2 CO 3 would lead to a built-in potential, preventing the charge separation, thus leading to the photodegradation activity recede [37]. By comparing the shapes of the photoluminescence spectra of U5.0 and N5.0, it is found that they exhibit similar PL spectra but different intensities.…”

“…Generally, the Bi 2 S 3 /(BiO) 2 CO 3 can be synthesized through a facile ion-exchange reaction between (BiO) 2 CO 3 and S 2-ions. Due to the rather low solubility of Bi 2 S 3 in water (K sp = 1.0 9 10 -97 ) [37], the formed Bi 2 S 3 should mainly deposit on the surface of (BiO) 2 CO 3 , and the amount of Bi 2 S 3 should be mainly determined by both the mass transfer of S 2-ions from bulk solution to the surface of (BiO) 2 CO 3 and the concentration of surface Bi 3? ions on (BiO) 2 CO 3 .…”

Study of the sulfurized (BiO)2CO3 as efficient visible-light induced photocatalyst

“…The two intensive peaks at 1386 and 1466 cm -1 are assigned to the m 3 antisymmetric vibrational mode of the CO 3 2-group, while the peaks at 1066 and 848 cm -1 are ascribed to the symmetric stretching mode m 1 and the out-of-plane bending mode m 2 , respectively [41]. It is noteworthy that the peaks at 1107 cm -1 corresponds to the Bi-S bond vibrations [42] were observed for sulfurized samples. Furthermore, this intensity of this peak at 1107 cm -1 enhanced slightly with increase of sulfurization, which implied that S atom successfully was introduced into (BiO) 2 CO 3 .…”

Facile Synthesis and Characterization of Novel CdS/BiOI Heterojunctions with Enhanced Visible-Light Photocatalytic Performances

“…Among them, BiOI has the maximum absorption abi-lity in visible-light region due to its smallest band gap (≈ 1.8 eV) [13]. However, due to the low separation efficiency of photogenerated electrons and holes, the photocatalytic activity of BiOI is very poor [14][15][16].…”