Preparation method of efficient Bi2MoO6 coated BiVO4 heterojunction photoelectrode system

Abstract

The invention belongs to the technical field of photocatalysis, and particularly relates to a preparation method of an efficient Bi2MoO6 coated BiVO4 heterojunction photoelectrode system. FTO conductive glass serves as a substrate to be soaked in BiOI deposition liquid, a BiOI film is formed on the substrate through electrochemical deposition, and then a pure BiVO4 film is formed on the surface ofthe substrate through a point coating and annealing method; and the substrate is soaked into a deposition solution containing bismuth nitrate and sodium molybdate, and the Bi2MoO6 coated BiVO4 heterojunction photoelectrode system is prepared through a hydrothermal method. According to the BMO@BVO heterojunction photoelectrode system, Bi2MoO6 is coated on BiVO4, is in good contact with BiVO4 and forms a heterojunction II. The photo-generated current densities of BMO@BVO2 under the light irradiation of AM 1.5 G (100mW. Cm <-2 >) and lambda >420nm (100mW. Cm <-2 >) are 1.47 mA.cm <-2 > and 1.11mA.cm <-2 > respectively, and are 4.9 times and 3.9 times of those of pure BiVO4 respectively; therefore, the method is efficient and high in photoelectrochemical water splitting performance.

Description

technical field [0001] The invention belongs to the technical field of photocatalysis, in particular to a kind of efficient Bi 2 MoO 6 Coated BiVO 4 A method for preparing a heterojunction photoelectrode system. Background technique [0002] Since the discovery of TiO 2 Since solar energy can be used to split water to produce hydrogen, photoelectrochemical water splitting technology is increasingly considered as a potential technology for providing green energy and solving environmental pollution problems. At the same time, more and more photocatalysts are used in photoelectrochemical splitting of water to produce hydrogen and oxygen, such as ZnO, WO 3 and BiVO 4 Wait. However, TiO 2 The bandgap of ZnO and ZnO is wide, so that it can only absorb less than 5% of the ultraviolet light in the solar spectrum. And BiVO 4 Due to its suitable bandgap width (2.4-2.6eV), non-toxicity and high stability, it is considered to be one of the most promising photoelectrode material...

AI Technical Summary

Problems solved by technology

However, TiO 2 The band gap of ZnO and ZnO is wide, so that it can only absorb less than 5% of the ultraviolet light in the solar spectrum

However, currently for Bi 2 MoO 6 / BiVO 4 There are few studies on the system, especially for Bi 2 MoO 6 / BiVO 4 There are fewer studies on systems for photoelectrochemical water splitting

BiVO was spin-coated 4 Coated in Bi 2 MoO 6 Bi prepared on nanorod arrays 2 MoO 6 / BiVO 4 Heterojunction photoelectrodes, discovering that Bi 2 MoO 6 / BiVO 4 Has a ratio Bi 2 MoO 6 and BiVO 4 Both have excellent photoelectrochemical properties, but the fly in the ointment is that after the formation of a heterojunction, the photogenerated electrons are generated by the Bi 2 MoO 6 The conduction band shifts to the cladding BiVO 4 on the conduction band, while the cladding BiVO 4 The contact area with the conductive substrate is small, and the transfer of photogenerated electrons from the material to the conductive substrate is relatively slow, which leads to the inability of the photogenerated carriers to be transported to the conductive substrate in a timely and effective manner, making Bi 2 MoO 6 / BiVO 4 The photoelectrochemical performance of the photoelectrode is not outstanding

[0004] Therefore, the design and fabrication of simple and efficient band-matched Bi 2 MoO 6 / BiVO 4 It is still a great challenge to realize the rapid transport of photogenerated carriers in the heterojunction photoelectrode system.

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