Method for inhibiting photo-corrosion of bismuth oxyhalide
阅读说明：本技术 一种抑制卤氧化铋光腐蚀的方法 (Method for inhibiting photo-corrosion of bismuth oxyhalide ) 是由 喻志阳 罗志珊 张诗佳 叶晓圆 于 2021-01-26 设计创作，主要内容包括：本发明涉及一种抑制卤氧化铋光腐蚀的方法,属于光催化材料技术领域。纯的卤氧化铋在光催化过程中会在其表面生成一圈钝化层(Bi-2O-3),严重阻碍了其光催化性能的表达。本发明通过原位光沉积硝酸钴,生成的氧化钴助催化剂与卤素原子发生合金化效应,形成三氧化钴铋(BiCoO-3)合金,包裹住卤氧化铋,有效抑制了其光腐蚀的同时提高了其光催化性能。本发明提供的制备方法,材料廉价,过程简单,条件可控,所得的三氧化钴铋(BiCoO-3)合金能有效改善卤氧化铋的光电化学性质,促进其电荷分离,并提高其光催化性能。(The invention relates to a method for inhibiting bismuth oxyhalide photo-corrosion, belonging to the technical field of photocatalytic materials. Pure bismuth oxyhalide can generate a circle of passivation layer (Bi) on the surface thereof in the photocatalysis process 2 O 3 ) Seriously hampering the expression of its photocatalytic properties. The cobalt nitrate is in-situ photo-deposited, and the generated cobalt oxide cocatalyst and halogen atoms generate alloying effect to form bismuth cobaltoxide (BiCoO) 3 ) The alloy is wrapped by the bismuth oxyhalide, and effectively inhibitsThe photo-corrosion of the catalyst improves the photocatalytic performance of the catalyst. The preparation method provided by the invention has the advantages of cheap materials, simple process and controllable conditions, and the obtained bismuth cobaltous oxide (BiCoO) 3 ) The alloy can effectively improve the photoelectrochemical property of the bismuth oxyhalide, promote the charge separation of the bismuth oxyhalide and improve the photocatalytic performance of the bismuth oxyhalide.)
1. A method of inhibiting photo-corrosion of bismuth oxyhalide, comprising: co-bismuth trioxide BiCoO as cocatalyst loaded on surface of bismuth oxyhalide3Inhibit the photo-corrosion of bismuth oxyhalide.
2. The method of inhibiting bismuth oxyhalide photo-corrosion according to claim 1, wherein: the bismuth oxyhalide BiOX comprises bismuth oxychloride BiOCl, bismuth oxybromide BiOBr or bismuth oxyiodide BiOI.
3. The method of inhibiting bismuth oxyhalide photo-corrosion according to claim 1, wherein: in particular to BiOX and cobalt nitrate hexahydrate Co (NO)3)2·6H2Forming BiCoO in an alloying manner in aqueous solution by in-situ photo-deposition3And is loaded on the surface of BiOX.
4. The method of inhibiting bismuth oxyhalide photo-corrosion according to claim 3, wherein: the light source of the in-situ light deposition is a xenon lamp, and particularly, the xenon lamp is irradiated for 10-60 min by ultraviolet light with the wavelength of more than 300 nm in the air atmosphere.
5. The method of inhibiting bismuth oxyhalide photo-corrosion according to claim 3, wherein: the BiCoO3The loading amount of the catalyst is 0.1-10 wt.%.
6. Bismuth cobaltous oxide BiCoO3The bismuth oxyhalide BiOX composite material is characterized in that: the BiCoO3Is loaded on the BiOX surface in an in-situ photo-deposition alloying way.
7. The composite material of claim 6, wherein: the bismuth oxyhalide is a bismuth oxyhalide nanosheet.
8. The composite material of claim 7, wherein: the bismuth oxyhalide nano-sheet is bismuth nitrate Bi (NO) pentahydrate3)3·5H2O is dissolved inAnd (3) after glycol is transferred to an injector, slowly injecting and dripping potassium halide dispersed in an aqueous solution, washing the obtained product by centrifugal water, and transferring the product to an aqueous solution with the pH value of 1 for hydrothermal reaction.
9. The composite material of claim 8, wherein: the slow injection is specifically a 2 mL/min drop.
10. The bismuth cobaltous trioxide BiCoO of claim 63The bismuth oxyhalide BiOX composite material is applied to a photocatalytic oxygen production system.
Technical Field
The invention relates to a method for inhibiting bismuth oxyhalide photo-corrosion, belonging to the technical field of photocatalytic materials.
Background
With the development of modern industry and the mass combustion of fossil fuels, environmental pollution and energy shortage are becoming more serious. Therefore, the treatment of environmental pollution and the development of renewable clean energy are of great significance for the development of national economy and the realization of sustainable development (Nat mater, 2017, 16, 23-34). Solar energy has been widely paid attention to as a clean, efficient and safe renewable energy source, and particularly, low-density solar energy is converted into high-density chemical energy by utilizing a semiconductor photocatalysis technology and is applied to degradation of organic pollutants and artificial photosynthesis to fix CO2The photocatalytic hydrogen and oxygen production and the conversion of organic functional groups have wide application prospects in solving the problems of environmental pollution and energy shortage, so that the development of a high-efficiency and high-stability photocatalyst is the premise for realizing large-scale application of a semiconductor photocatalytic technology (Adv mater, 2016, 28, 5778-93; J Am. chem, Soc, 2014, 136, 16728-31).
Bismuth oxyhalide (BiOX, X = Cl, Br, I) is a layered compound belonging to the P4/nmm space group and consisting of [ Bi [)2O2]2+The layer is sandwiched between two layers X-The composition between ions has been widely used in pharmaceutical (chem. rev., 1999, 99, 2601-. However, the bismuth oxyhalide is easily subjected to photo-corrosion on the surface after long-term illumination, so that the performance of the bismuth oxyhalide is greatly reduced, and the use of the bismuth oxyhalide in the field of photocatalysis is seriously hindered. Thus, openThe method for inhibiting the photo-corrosion of the bismuth oxyhalide is green, convenient and controllable, and has extremely important significance.
Disclosure of Invention
The invention aims to provide a method for inhibiting bismuth oxyhalide photo-corrosion.
In order to achieve the purpose, the invention adopts the following technical scheme:
a method for inhibiting photo-corrosion of bismuth oxyhalide is to load a cocatalyst of cobalt bismuth trioxide (BiCoO) on the surface of bismuth oxyhalide3Inhibiting bismuth oxyhalide photo-corrosion; the bismuth oxyhalide BiOX comprises bismuth oxychloride BiOCl, bismuth oxybromide BiOBr or bismuth oxyiodide BiOI.
The specific method is to mix BiOX and cobalt nitrate hexahydrate Co (NO)3)2·6H2Forming BiCoO in an alloying manner in aqueous solution by in-situ photo-deposition3And is loaded on the surface of BiOX.
The light source of the in-situ light deposition is a xenon lamp, and particularly, the xenon lamp is irradiated for 10-60 min by ultraviolet light with the wavelength of more than 300 nm in the air atmosphere.
Wherein the BiCoO3The loading amount of the catalyst is 0.1-10 wt.%.
Bismuth cobaltous oxide BiCoO3BiCoO/bismuth oxyhalide BiOX composite material3Loading on the BiOX surface in an in-situ light deposition alloying way; the bismuth oxyhalide is a bismuth oxyhalide nanosheet.
The bismuth oxyhalide nano-sheet is bismuth nitrate Bi (NO) pentahydrate3)3·5H2Dissolving O in ethylene glycol, transferring to an injector, slowly injecting potassium halide dispersed in an aqueous solution dropwise, washing the obtained product with centrifugal water, transferring to an aqueous solution with pH of 1, and performing hydrothermal treatment.
The bismuth cobaltous oxide BiCoO3The bismuth oxyhalide BiOX composite material is applied to a photocatalytic oxygen production system; 50 mg of the composite material and 0.197 g of sodium iodate NaIO were taken3Dispersing sacrificial agent in 100 mL water, transferring to oxygen generator, vacuumizing to remove air, irradiating with xenon lamp under ultraviolet light for several hoursThe resulting oxygen content was detected by on-line chromatography.
The invention has the following remarkable advantages:
(1) the invention has the advantages of low raw material price, simple preparation process and mild and controllable conditions.
(2) The cobalt trioxide bismuth/bismuth oxyhalide composite material synthesized by the invention has excellent anti-photo-corrosion property.
(3) The cobalt oxide bismuth trioxide/bismuth oxyhalide composite material synthesized by the invention can be applied to photolysis of water to produce oxygen, and the catalyst is stable, easy to recover and recyclable.
(4) The cobalt oxide bismuth trioxide/bismuth oxyhalide composite material synthesized by the invention can be applied to the field of photocatalysis, and has potential application capability in other fields such as photoelectricity, catalysis, organic pollutant photodegradation, adsorption, energy storage and the like.
Drawings
Fig. 1 is a Scanning Electron Micrograph (SEM) of (a) bismuth oxybromide (BiOBr), (b) an X-ray powder diffraction pattern (XRD) of bismuth oxybromide (BiOBr), (c) a Transmission Electron Micrograph (TEM) of bismuth oxybromide (BiOBr), and (d) an energy spectrum (EDS) of bismuth oxybromide (BiOBr) obtained in example 1, showing a uniform distribution of three elements of bismuth (Bi), oxygen (O), and bromine (Br).
FIG. 2 is a transmission electron micrograph of photo-etching of bismuth oxybromide (BiOBr) synthesized in example 1 under vacuum with sodium iodide sacrificial agent and with xenon lamp under UV irradiation (wavelength > 300 nm) for different periods of time. (a) 30 min of light corrosion (the inset is the corresponding high power transmission electron microscope image), (b) 1 h of light corrosion, (c) 3h of light corrosion, and (d) an EDS energy spectrum after 30 min of light corrosion of bismuth oxybromide (BiOBr).
Fig. 3 is transmission electron micrographs of (a) macroscopic and (b) macroscopic of the cobalt trioxide bismuth/bismuth oxybromide (BiOBr) composite synthesized in example 1. (c) And (d) EDS spectra of medium and high power of bismuth oxide/bismuth oxybromide (BiOBr) composite material, respectively.
Fig. 4 is a graph of (a) photocurrent response and (b) long-term photocatalytic oxygen generation performance of the cobalt bismuth trioxide/bismuth oxybromide (BiOBr) composite synthesized in example 1.
Fig. 5 is a high-power transmission electron microscope image of the cobalt trioxide bismuth/bismuth oxybromide (BiOBr) composite material synthesized in example 1 after oxygen (a) 1 h, (b) 3h and (c) are generated for a long time.
Detailed Description
In order to make the present invention more comprehensible, the technical solutions of the present invention are further described below with reference to specific embodiments, but the present invention is not limited thereto.
Example 1
1) Preparation of bismuth oxybromide (BiOBr) nanosheets: 1 mmol of bismuth nitrate pentahydrate (Bi (NO)3)3·5H2O) was dissolved in 30 mL of ethylene glycol solution and transferred to a 50 mL range syringe, and then slowly injected at a rate of 2 mL/min, and dropped into 30 mL of an aqueous solution containing 3 mmol of potassium bromide (KBr), and a white precipitate was immediately generated. After the completion of the dropping, the mixture was stirred for 30 min, and the product was washed 3 times with centrifugal water and transferred to a solution containing 30 mL of an aqueous solution having pH 1, and finally charged into a 50 mL hydrothermal reactor, and hydrothermal at 140 ℃ for 8 h. After the reaction is finished, centrifugally washing with water and ethanol for several times, and then placing in an oven at 60 ℃ for overnight drying to obtain bismuth oxybromide (BiOBr) nanosheets.
2) Preparing a cobalt nitrate hexahydrate aqueous solution: 1 g of cobalt nitrate hexahydrate solid is dissolved in 50 mL of water to obtain the cobalt nitrate hexahydrate solid.
3) Preparing a cobalt bismuth trioxide/bismuth oxybromide (BiOBr) composite material: 50 mg of prepared bismuth oxybromide (BiOBr) was dispersed in 100 mL of water, and an appropriate amount of an aqueous solution of cobalt nitrate hexahydrate (1 wt.%) was added according to the mass ratio, followed by irradiating the mixed solution with ultraviolet light through a xenon lamp for 30 min. And (3) centrifugally washing the reacted mixed solution, and placing the washed mixed solution in a 60 ℃ oven for overnight drying to obtain the cobalt bismuth trioxide/bismuth oxybromide (BiOBr) composite material.
4) Evaluation of photocatalytic oxygen generation performance: 50 mg of the prepared cobalt bismuth trioxide/bismuth oxybromide (BiOBr) composite photocatalyst and 0.197 g of sodium iodate sacrificial agent are used for testing the photocatalytic oxygen production performance of the BiOBr and the cobalt bismuth trioxide/bismuth oxybromide (BiOBr) composite material in a 100 mL aqueous solution system after vacuum pumping.
Example 2
1) Preparation of bismuth oxychloride (BiOCl) nanosheets: 1 mmol of bismuth nitrate pentahydrate (Bi (NO)3)3·5H2O) was dissolved in 30 mL of ethylene glycol solution and transferred to a 50 mL-range syringe, and then slowly injected at a rate of 2 mL/min, and dropped into 30 mL of an aqueous solution containing 3 mmol of potassium chloride (KCl), and a white precipitate was immediately generated. After the completion of the dropping, the mixture was stirred for 30 min, and the product was washed 3 times with centrifugal water and transferred to a solution containing 30 mL of an aqueous solution having pH 1, and finally charged into a 50 mL hydrothermal reactor and hydrothermally heated at 140 ℃ for 4 h. After the reaction is finished, centrifugally washing with water and ethanol for several times, and then placing in an oven at 60 ℃ for overnight drying to obtain the bismuth oxychloride (BiOCl) nanosheet.
2) Preparing a cobalt nitrate hexahydrate aqueous solution: 1 g of cobalt nitrate hexahydrate solid is dissolved in 50 mL of water to obtain the cobalt nitrate hexahydrate solid.
3) Preparing a cobalt bismuth trioxide/bismuth oxychloride (BiOCl) composite material: 50 mg of prepared bismuth oxychloride (BiOCl) was dispersed in 100 mL of water, and an appropriate amount of an aqueous solution of cobalt nitrate hexahydrate (3 wt.%) was added according to the mass ratio, followed by irradiating the mixed solution with ultraviolet light through a xenon lamp for 10 min. And (3) centrifugally washing the reacted mixed solution, and placing the washed mixed solution in a 60 ℃ oven for overnight drying to obtain the cobalt bismuth trioxide/bismuth oxybromide (BiOBr) composite material.
4) Evaluation of photocatalytic oxygen generation performance: 50 mg of the prepared cobalt bismuth trioxide/bismuth oxybromide (BiOBr) composite photocatalyst and 0.197 g of sodium iodate sacrificial agent are used for testing the photocatalytic oxygen production performance of the BiOBr and the cobalt bismuth trioxide/bismuth oxybromide (BiOBr) composite material in a 100 mL aqueous solution system after vacuum pumping.
Example 3
1) Preparation of bismuth oxyiodide (BiOI) nanosheets: 1 mmol of bismuth nitrate pentahydrate (Bi (NO)3)3·5H2O) was dissolved in 30 mL of ethylene glycol solution and transferred to a 50 mL-range syringe, and then slowly injected at a rate of 2 mL/min, and dropped into 30 mL of an aqueous solution containing 3 mmol of potassium iodide (KI), and a white precipitate was immediately produced. After the completion of the dropping, the mixture was stirred for 30 min, and the product was washed 3 times with centrifugal water and transferred to a solution containing 30 mL of water having a pH of 1Finally, the solution is put into a 50 mL hydrothermal kettle and is hydrothermal for 10 hours at 160 ℃. After the reaction is finished, centrifugally washing with water and ethanol for several times, and then placing in an oven at 60 ℃ for overnight drying to obtain the bismuth oxyiodide (BiOI) nanosheet.
2) Preparing a cobalt nitrate hexahydrate aqueous solution: 1 g of cobalt nitrate hexahydrate solid is dissolved in 50 mL of water to obtain the cobalt nitrate hexahydrate solid.
3) Preparing a cobalt bismuth trioxide/bismuth oxyiodide (BiOI) composite material: 50 mg of prepared bismuth oxyiodide (BiOI) was dispersed in 100 mL of water, and an appropriate amount of an aqueous solution of cobalt nitrate hexahydrate (5 wt.%) was added according to the mass ratio, followed by irradiating the mixed solution with ultraviolet light through a xenon lamp for 20 min. And (3) centrifugally washing the reacted mixed solution, and placing the washed mixed solution in a 60 ℃ oven for overnight drying to obtain the cobalt bismuth trioxide/bismuth oxyiodide (BiOI) composite material.
4) Evaluation of photocatalytic oxygen generation performance: 50 mg of the prepared cobalt bismuth trioxide/bismuth oxybromide (BiOBr) composite photocatalyst and 0.197 g of sodium iodate sacrificial agent are used for testing the photocatalytic oxygen production performance of the BiOBr and the cobalt bismuth trioxide/bismuth oxybromide (BiOBr) composite material in a 100 mL aqueous solution system after vacuum pumping.
Example 4
1) Preparation of bismuth oxyiodide (BiOI) nanosheets: 1 mmol of bismuth nitrate pentahydrate (Bi (NO)3)3·5H2O) was dissolved in 30 mL of ethylene glycol solution and transferred to a 50 mL-range syringe, and then slowly injected at a rate of 2 mL/min, and dropped into 30 mL of an aqueous solution containing 3 mmol of potassium iodide (KI), and a white precipitate was immediately produced. After the completion of the dropping, the mixture was stirred for 30 min, and the product was washed 3 times with centrifugal water and transferred to a solution containing 30 mL of pH 1 in water, and finally charged into a 50 mL hydrothermal reactor, and hydrothermal at 140 ℃ for 16 h. After the reaction is finished, centrifugally washing with water and ethanol for several times, and then placing in an oven at 60 ℃ for overnight drying to obtain the bismuth oxyiodide (BiOI) nanosheet.
2) Preparing a cobalt nitrate hexahydrate aqueous solution: 1 g of cobalt nitrate hexahydrate solid is dissolved in 50 mL of water to obtain the cobalt nitrate hexahydrate solid.
3) Preparing a cobalt bismuth trioxide/bismuth oxyiodide (BiOI) composite material: 50 mg of prepared bismuth oxyiodide (BiOI) was dispersed in 100 mL of water, and an appropriate amount of an aqueous solution of cobalt nitrate hexahydrate (10 wt.%) was added according to the mass ratio, followed by irradiating the mixed solution with ultraviolet light through a xenon lamp for 20 min. And (3) centrifugally washing the reacted mixed solution, and placing the washed mixed solution in a 60 ℃ oven for overnight drying to obtain the cobalt bismuth trioxide/bismuth oxyiodide (BiOI) composite material.
4) Evaluation of photocatalytic oxygen generation performance: 50 mg of the prepared cobalt bismuth trioxide/bismuth oxybromide (BiOBr) composite photocatalyst and 0.197 g of sodium iodate sacrificial agent are used for testing the photocatalytic oxygen production performance of the BiOBr and the cobalt bismuth trioxide/bismuth oxybromide (BiOBr) composite material in a 100 mL aqueous solution system after vacuum pumping.
Example 5
1) Preparation of bismuth oxybromide (BiOBr) nanosheets: 1 mmol of bismuth nitrate pentahydrate (Bi (NO)3)3·5H2O) was dissolved in 30 mL of ethylene glycol solution and transferred to a 50 mL range syringe, and then slowly injected at a rate of 2 mL/min, and dropped into 30 mL of an aqueous solution containing 3 mmol of potassium bromide (KBr), and a white precipitate was immediately generated. After the completion of the dropping, the mixture was stirred for 30 min, and the product was washed 3 times with centrifugal water and transferred to a solution containing 30 mL of pH 1 in water, and finally charged into a 50 mL hydrothermal reactor, and hydrothermal at 140 ℃ for 16 h. After the reaction is finished, centrifugally washing with water and ethanol for several times, and then placing in an oven at 60 ℃ for overnight drying to obtain bismuth oxybromide (BiOBr) nanosheets.
2) Preparing a cobalt nitrate hexahydrate aqueous solution: 1 g of cobalt nitrate hexahydrate solid is dissolved in 50 mL of water to obtain the cobalt nitrate hexahydrate solid.
3) Preparing a cobalt bismuth trioxide/bismuth oxybromide (BiOBr) composite material: 50 mg of prepared bismuth oxybromide (BiOBr) was dispersed in 100 mL of water, and an appropriate amount of an aqueous solution of cobalt nitrate hexahydrate (3 wt.%) was added according to the mass ratio, followed by irradiating the mixed solution with ultraviolet light through a xenon lamp for 20 min. And (3) centrifugally washing the reacted mixed solution, and placing the washed mixed solution in a 60 ℃ oven for overnight drying to obtain the cobalt bismuth trioxide/bismuth oxybromide (BiOBr) composite material.
4) Evaluation of photocatalytic oxygen generation performance: 50 mg of the prepared cobalt bismuth trioxide/bismuth oxybromide (BiOBr) composite photocatalyst and 0.197 g of sodium iodate sacrificial agent are used for testing the photocatalytic oxygen production performance of the BiOBr and the cobalt bismuth trioxide/bismuth oxybromide (BiOBr) composite material in a 100 mL aqueous solution system after vacuum pumping.
Fig. 1 is bismuth oxybromide (BiOBr) nanoplates synthesized in example 1. (a) The figure shows that the appearance is square and the size is below 2 microns. (b) The figure is the X-ray powder diffraction pattern (XRD) of the bismuth oxybromide (BiOBr) and can be seen to be consistent with the PDF card of the BiOBr, which indicates that (c) bismuth oxybromide (BiOBr) nanosheets are successfully synthesized, and the further figure (d) shows the energy spectrum (EDS) of the bismuth oxybromide (BiOBr), and the uniform distribution of three elements of bismuth (Bi), oxygen (O) and bromine (Br) can be seen.
FIG. 2 is a diagram of transmission electron microscopy measurements of bismuth oxybromide (BiOBr) synthesized in example 1 under vacuum with sodium iodonate as sacrificial agent, after exposure to UV light (wavelength > 300 nm) for various periods of time with a xenon lamp. From the graph (a), it is clear that significant photo-corrosion occurred after the bismuth oxybromide (BiOBr) light irradiation for 30 min. When the illumination time is increased to 1 h (b) and 3h (c), the passivation layer covered on the surface is obviously increased, then EDS (electronic discharge spectroscopy) test is carried out on the passivation layer (d), the passivation layer is obviously formed by Bi and O elements, and the energy spectrum data of five different positions (table 1) are quantitatively analyzed through EDS, so that the passivation layer is bismuth trioxide (Bi)2O3) Further, high-magnification TEM in the (a) picture shows that the interplanar spacing of 0.28 nm belongs to Bi2O3The (200) plane of (1).
Fig. 3 is a transmission electron microscope and EDS energy spectra of the cobalt trioxide bismuth/bismuth oxybromide (BiOBr) composite synthesized in example 1. As can be seen from the low power transmission electron micrographs of (a) and (b), the loaded bismuth cobaltoxide can effectively wrap bismuth oxybromide (BiOBr) for one circle, and the passivation layer Bi of the bismuth oxybromide is inhibited2O3The growth of (2). (c) And (d) EDS energy spectra of the cobalt oxide bismuth/bismuth oxybromide (BiOBr) composite material at medium and high times respectively, wherein Bi, Co and O elements are effectively inhibited after being loaded at the outermost periphery2O3And (5) growing. Also we have determined by EDS quantitative analysis (table 2) five particles of Bi, Co and O elements, Bi: co: the atomic weight ratio of O is 1: 1: 3, further specifically defined asBiCoO3A substance.
Fig. 4 is a diagram of the photoelectrochemical properties of the cobalt bismuth trioxide/bismuth oxybromide (BiOBr) composite synthesized in example 1. As is evident from the graph (a), the photocurrent response of bismuth oxybromide (BiOBr) loaded with bismuth cobaltoxide is obviously improved. (b) The long-time oxygen generation performance graph can also see that the performance of pure bismuth oxybromide (BiOBr) gradually flattens after illumination for 5 hours, and the performance of bismuth oxybromide (BiOBr) loaded with bismuth cobaltoxide is not obviously reduced in the 12-hour test process. It can be seen that the load of the cobalt bismuth trioxide effectively inhibits the photo-corrosion of bismuth oxybromide (BiOBr), so that the photocatalytic performance of the bismuth oxybromide (BiOBr) is greatly improved, and the light stability of the bismuth oxybromide (BiOBr) is also improved.
Fig. 5 is a transmission electron microscope image of the cobalt trioxide bismuth/bismuth oxybromide (BiOBr) composite synthesized in example 1 after long-term oxygen generation. (a) The images are TEM images after 1 h of reaction, and it can be seen that cobalt bismuth trioxide particles still exist on the surface of the sample, (b) is 3h, and (c) is TEM images after long-time oxygen production tests are completed, the existence of the cobalt bismuth trioxide particles can be clearly seen, which indicates that the cobalt bismuth trioxide does not fall off in the reaction process, and the bismuth oxybromide (BiOBr) does not have obvious photo-corrosion phenomenon.
Table 1 EDS spectra data of photo-etched products at different locations after bismuth oxybromide (BiOBr) photo-etching.
Table 2 EDS spectra data for different cobalt bismuth trioxide particles in a cobalt bismuth trioxide/bismuth oxybromide (BiOBr) composite.
The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.