CN-122010176-A - Novel oxysulfide and light absorption regulation and control method thereof

Abstract

The invention provides a novel oxysulfide and a light absorption property regulating and controlling method thereof, which have a chemical formula of SrGaSbO 3 S, belong to orthorhombic Pnma, have a two-dimensional lamellar structure and are formed by alternately stacking [ GaSbO 3 S] 2‑ layers and interlayer Sr 2+ ions. The material is placed in molten alkali metal halide for annealing treatment, and an amorphous layer is formed on the surface due to ion topology erosion, so that the optical band gap of the material is obviously narrowed, the color is changed from pale yellow to orange from 2.11 eV to 1.69 eV. The oxysulfide and the band gap regulating method thereof have important significance in the fields of photocatalysis, photoelectric conversion and the like.

Inventors

• WANG RUIQI
• ZHAO RAN

Assignees

• 中国科学院大学

Dates

Publication Date

20260512

Application Date

20260204

Claims (6)

1. 1. A novel oxysulfide, characterized by: (1) The chemical formula is SrGaSbO 3 S, which belongs to orthorhombic system and Pnma space group. (2) Is formed by alternately stacking [ GaSbO 3 S] 2- layers and interlayer Sr 2+ ions. (3) Sr has a valence of +2, sb has a valence of +3, ga has a valence of +3, O has a valence of-2, and S has a valence of-2. .
2. 2. A method for preparing oxysulfide according to claim 1, wherein the raw materials containing Sr element, ga element, sb element, O element and S element are placed under vacuum condition, and the temperature is kept at 600-800 ℃ for more than 24 hours, and then the temperature is reduced and cooled.
3. 3. The method of manufacturing according to claim 2, comprising the steps of: (1) In a glove box, mixing and grinding strontium sulfide, antimonous oxide, gallium oxide and cesium iodide uniformly, filling the mixture into a quartz tube, heating the quartz tube to 700-800 ℃ after vacuum sealing, and cooling the quartz tube after keeping the temperature for more than 24 hours. (2) And (3) washing the product obtained in the step (I) with deionized water, treating with acetone, and drying to obtain the material.
4. 4. A method of surface modification of oxysulfides according to claim 1, wherein surface ions of the material are selectively eluted, resulting in surface amorphization, substantially reducing the optical bandgap of the material.
5. 5. The method for surface modification according to claim 4, comprising the steps of: (1) SrGaSbO 3 S crystals are mixed with one or more of alkali metal halides AX (A= Na, K, rb, cs; X=Cl, br, I), the mixture is sealed in a quartz tube under vacuum, heated to 700-800 ℃, kept for 6-48 hours, and finally cooled rapidly to room temperature. (2) And (3) cleaning the mixture obtained in the step (I) with deionized water, treating with acetone, and drying to obtain the modified material.
6. 6. Use of an oxysulfide according to any one of claims 1 to 5 for photocatalytic decomposition of water, degradation of organic pollutants.

Description

Novel oxysulfide and light absorption regulation and control method thereof Technical Field The invention belongs to the field of inorganic materials, and particularly relates to a preparation and light absorption regulation method of inorganic oxysulfide crystals. Background Oxysulfide is a heteroanion compound with development prospect, and is characterized in that two anions of O 2⁻ and S 2⁻ exist in a crystal structure. These oxysulfides with different structural dimensions have become ideal candidates for a wide range of applications, ranging from quantum materials such as superconductors, to functional materials such as optoelectronics, thermoelectric conversion, and nonlinear optics (NLO). They exhibit unique coordination chemistry, which results from the formation of a heteroanion [ MO xSy ] motif promoted by a metal ion (M) with suitable bonding preferences. In addition, by introducing high electronegativity cations (such as alkali metal ion a +, alkaline earth metal ion Ae 2+ and rare earth metal ion Ln 3+) as structural templates into these compounds, the spatial arrangement and connection mode of these motifs can be effectively controlled. The method can further increase the diversity of structures and bonds, thereby opening a way for the structural and functional design of oxysulfide systems. At the moment that energy crisis and environmental problems are increasingly prominent, visible light is used as a novel clean and renewable energy source, and efficient capturing and conversion of the visible light is becoming a research hotspot in the field of material science. The light absorption property of the oxysulfide is closely related to the electronic structure of the hetero anion [ MO xSy ] primitive, the electronegativity difference and the orbit interaction of O 2⁻ and S 2⁻ enable the energy band structure of the oxysulfide to be flexibly regulated through structure regulation, and the capturing and utilizing efficiency of visible light can be further improved by optimizing the type of metal ions M, regulating the O/S ratio in the [ MO xSy ] primitive, introducing proper doping elements and structural templates, and carrying out surface component regulation (such as regulating the surface O/S element ratio, modifying functional surface species, constructing a surface heterostructure and the like) so as to accurately regulate the light absorption range of the oxysulfide, widen the light absorption range to the visible light region, and simultaneously optimize the surface light absorption efficiency and the surface separation characteristic of photo-generated carriers. Meanwhile, the crystal structure and electronic state distribution of oxysulfide are reasonably regulated and controlled, the recombination probability of photo-generated carriers can be reduced, the separation and transmission capacity of photo-generated charges is enhanced, the energy conversion performance under the drive of visible light is further improved, a foundation is laid for practical application of the composite material in the fields of solar photocatalytic water decomposition, visible light photoelectric conversion, photo-thermal conversion and other energy conversion, and efficient utilization and development of clean renewable energy are promoted. Disclosure of Invention The invention provides a preparation and light absorption regulation method of a novel oxysulfide crystal. In a first aspect, the present invention provides a novel oxysulfide SrGaSbO 3 S, belonging to the orthorhombic system, the space group being Pnma. The oxysulfide has a layered structure, and two-dimensional layers are formed by alternately stacking [ GaSbO 3S]2- layers of anions and Sr 2+ cation layers, wherein [ GaSbO 3S]2- layers are connected by [ GaO 2S2]3- tetrahedral chains and [ SbO 3]2- triangular pyramids through common vertexes. Wherein the [ GaO 2S]3- chain is formed by connecting [ GaO 2S2]5- tetrahedron through a shared top angle S atom. Adjacent [ GaO 2S]3- chains are connected with each other through the [ SbO 3]3- group and sharing O atoms. In a second aspect, the invention provides a preparation method of the novel oxysulfide, which comprises the steps of placing raw materials containing Sr element, ga element, sb element, O element and S element under a vacuum condition, preserving heat at 600-800 ℃ for more than 24 hours, and cooling. The mole ratio of Sr element, ga element, sb element, O element and S element in the raw materials is (1-1.5): 1:1 (3-3.5): 1. The high temperature reaction may include heating from room temperature to 600-800 ℃ within 10 hours. The high temperature reaction may include heating to 700-800 ℃ and then maintaining the temperature for 24-72 hours, then cooling to 500 ℃ within 24-72 hours, and then naturally cooling to room temperature. In the above preparation process, a flux may be added to the reaction raw materials, and the kind of the flux includes, but is not limited to, alkali metal halid