Controlled synthesis of olive-shaped Bi2S3/BiVO4 microspheres through a limited chemical conversion route and enhanced visible-light-responding photocatalytic activity

Abstract

Well-defined olive-shaped Bi(2)S(3)/BiVO(4) microspheres were synthesized through a limited chemical conversion route (LCCR), where olive-shaped BiVO(4) microspheres and thioacetamide (TAA) were used as precursors and sulfur source, respectively. The as-synthesized products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high-resolution transmission microscope (HRTEM), X-ray photoelectron spectra (XPS), UV-visible diffuse-reflectance spectroscopy (UV-vis DRS), and photoluminescence (PL) spectra in detail. Compared with pure BiVO(4) microspheres and Bi(2)S(3) nanorods, the Bi(2)S(3)/BiVO(4) products showed obviously enhanced photocatalytic activity for the degradation of rhodamine B (Rh B) in aqueous solution under visible-light irradiation (λ > 400 nm). In addition, the Bi(2)S(3)/BiVO(4) composite microspheres showed good visible-light-driven photocatalytic activity for the degradation of refractory oxytetracycline (OTC) as well. On the basis of UV-vis DRS, the calculated energy band positions, and PL spectra, the mechanism of enhanced photocatalytic activity of Bi(2)S(3)/BiVO(4) was proposed. The present study provides a new strategy to design composite materials with enhanced photocatalytic performance.

Synthesis of Bi2S3/BiVO4 Heterojunction with a One-Step Hydrothermal Method Based on pH Control and the Evaluation of Visible-Light Photocatalytic Performance

“…Both BiVO 4 [40,41] and Bi 2 S 3 [22,42,43,44] display characteristics of direct transition. The light absorption properties and the band gap of the semiconductor can be determined based on UV-Vis absorption spectra (Figure 4a).…”

“…Therefore, Bi 2 S 3 can be combined with n-type semiconductor BiVO 4 to form a heterojunction with a strong capacity for visible light absorption. Using thioacetamide as a sulfur source, De-Kun Ma et al [22] developed a two-step hydrothermal method to synthesize olive-shaped Bi 2 S 3 /BiVO 4 microspheres with a limited chemical conversion route and enhanced photocatalytic activity. Canjun Liu et al [23] used thiourea as a sulfur source in a two-step method for synthesizing Bi 2 S 3 nanowires on BiVO 4 nanostructures with enhanced photoelectrochemical performance.…”

Cr(VI) remediation from aqueous environment through modified-TiO2-mediated photocatalytic reduction

“…The recombination of the photogenerated charge carriers is not only suppressed but also the spectral response of TiO 2 is extended to the visible spectrum by combining these metal oxides [159,161]. Moreover, formation of a p–n heterojunction is another strategy to facilitate the effective separation of electron–hole pairs and to extend light absorption to the red end of the solar spectrum [162–164]. The p–n junction is formed by coupling a p-type (hole-rich) semiconductor with n-type (electron-rich) TiO 2 .…”

Sequential ionic layer adsorption and reaction (SILAR) deposition of Bi4Ti3O12 on TiO2: an enhanced and stable photocatalytic system for water purification

“…However, it is important to note that lowered PL intensity in the range that BTO absorbs may in fact be due simply to re-adsorption of emitted photons by BTO, and not separation of charges. This has often been overlooked in previous reports, [43][44][45] and should be considered. Therefore, in this work the Tauc plot of 7× BTO has been overlayed with its PL spectrum.…”