Interface Engineering of a 2D/2D BiVO₄/Bi₄V₂O₁₀ Heterostructure with Improved Photocatalytic Photoredox Activity

Abstract

Bismuth vanadate (BiVO 4 ) is a promising photocatalyst for water pollution degradation and photocatalytic oxygen evolution. In this work, we prepared 2D/2D BiVO 4 −Bi 4 V 2 O 10 heterostructure with tight interfacial contact via a facile one-step hydrothermal process. The crystal structure and morphology of the samples could be easily regulated by changing the pH values of the solution. The BiVO 4 − Bi 4 V 2 O 10 heterostructure exhibited an enhanced photodegradation rate of Cr(VI) and oxygen evolution that of bare BiVO 4 , indicating that the synergistic effect and the interfacial fusions between BiVO 4 and Bi 4 V 2 O 10 can effectively promote the migration and separation rate of photoexcited charge carriers.

Intrinsic Mechanism Analyses of Significantly Enhanced Photoelectrochemical Performance of the Bi2MoO6/BiVO4 System

“…Figure b illustrates the Raman spectra of the prepared photoelectrodes. The peak at 815 cm –1 in the Raman spectrum of the BiVO 4 photoelectrode corresponds to the symmetric stretching mode of VO 4 2– , and those at 123 and 208 cm –1 are attributed to the bending mode of VO 4 , − which demonstrates the successful synthesis of BiVO 4 . The peaks at 715, 796, and 844 cm –1 of the Bi 2 MoO 6 photoelectrode are due to the stretching mode of Mo–O in octahedral MoO 6, − indicating the successful preparation of Bi 2 MoO 6 .…”

“…The peak at 815 cm –1 in the Raman spectrum of the BiVO 4 photoelectrode corresponds to the symmetric stretching mode of VO 4 2– , and those at 123 and 208 cm –1 are attributed to the bending mode of VO 4 , − which demonstrates the successful synthesis of BiVO 4 . The peaks at 715, 796, and 844 cm –1 of the Bi 2 MoO 6 photoelectrode are due to the stretching mode of Mo–O in octahedral MoO 6, − indicating the successful preparation of Bi 2 MoO 6 . After loading different amounts of Bi 2 MoO 6 on BiVO 4 , the peak at 815 cm –1 of BMO/BVO-1, BMO/BVO-2, BMO/BVO-3, and BMO/BVO-4 is slightly wider than that of pure BiVO 4 , which is caused by the formation of heterojunctions between Bi 2 MoO 6 and BiVO 4 .…”

“…Since Fujishima and Honda reported that TiO 2 could split water to produce hydrogen using solar energy in 1972, the photoelectrochemical (PEC) technology has increasingly been considered as a potential one to provide green energy. More and more photocatalysts were used in the field of photoelectrochemistry, such as TiO 2 , − ZnO, − WO 3 , , and BiVO 4 . − TiO 2 and ZnO are more commonly used; however, they have wide band gaps. Semiconductors with wide band gaps normally have low efficiency of the absorption and utilization of light; therefore, they cannot effectively convert solar energy into chemical energy.…”

Hierarchical Nanostructured BiVO4/Bi4V2O10 Heterojunctions for Piezocatalytic Degradation of Organic Dyes

“…Because pure Bi 4 V 2 O 10 is difficult to be synthesized, the energy band potentials obtained through the BV/BVO-3 samples can be approximated as the CB and VB positions of Bi 4 V 2 O 10 , given the high content of Bi 4 V 2 O 10 in BV/BVO-3. In fact, the same approach was adopted by other scientists because of the difficulty in obtaining pure Bi 4 V 2 O 10 . Therefore, based on the VB and CB positions, it can be inferred that BiVO 4 and Bi 4 V 2 O 10 form a type-II heterojunction.…”

Visible–near-Infrared Light-Driven Photocatalytic Characteristics of Er3+/Yb3+-Codoped BiOBr Upconverting Microparticles for Tetracycline Degradation

“…In comparison with other semiconductors, the photocatalytic capacities of bismuth-based semiconductors have been extensively explored because of their advantages of a suitable energy band gap E g , high physical/chemical stability, eco-friendly characteristics, and so forth. − Particularly, BiOX (X = I, Cl, F, Br), which is part of bismuth-containing semiconductors, has attracted increasing attention because of its unusual layered structure (i.e., [−X–Bi–O–O–Bi–X] layers) and admirable photocatalytic activities. − By means of the Van de Waals interaction, [Bi 2 O 2 ] 2+ slabs are interleaved by double X – slabs, in which an intrinsic built-in electric field exists between [Bi 2 O 2 ] 2+ and 2X – slabs. , The separation of photogenerated electron–hole (e – –h + ) pairs leads to the excellent photocatalytic performance of BiOX compounds. Although the UV–visible light-driven photodegradation is realized in BiOX compounds, − they are still hardly excited by NIR light, which occupies around 50% of the energy of sunlight. , Hence, it is necessary to improve the light harvesting ability of BiOX compounds.…”