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CN-117945452-B - Lead-free halide Cs (Ag1-xCux)2I3Is prepared from (1) and its application

CN117945452BCN 117945452 BCN117945452 BCN 117945452BCN-117945452-B

Abstract

The invention discloses a lead-free halide Cs (Ag 1‑ x Cu x ) 2 I 3 and application thereof, which belong to the field of luminescent materials, and the invention prepares a Cu + and Ag + doped Cs (Ag 1‑x Cu x ) 2 I 3 lead-free halide), which is prepared by firstly dissolving CsI, agI and CuI in a mixed solvent of N, N-Dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), heating and stirring for 6 hours at 20-90 ℃ to completely dissolve the Cs, then titrating with methanol, stopping titration when white powder appears, then filtering with a filter head, injecting the filtered transparent solution into a beaker, sealing the mouth of the beaker with small-pore-filled tinfoil and paraffin film, finally placing a growing device into a sealed large beaker filled with methanol, and keeping the temperature of the beaker for 2-7 days at 40-80 ℃ to obtain Cs (Ag 1‑x Cu x ) 2 I 3 crystals, wherein the prepared Cs (Ag 1‑x Cu x ) 2 I 3 crystals can be applied to degradation of organic pollutants).

Inventors

  • ZHU YAN
  • XU YUANYUAN
  • WANG WENZHEN

Assignees

  • 上海电子信息职业技术学院

Dates

Publication Date
20260508
Application Date
20240126

Claims (4)

  1. 1. The application of lead-free halide Cs (Ag 1-x Cu x ) 2 I 3 in photocatalytic degradation of organic pollutants is characterized in that the specific preparation steps of the lead-free halide Cs (Ag 1-x Cu x ) 2 I 3 are as follows: (1) CsI, agI and CuI are dissolved in a mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide, and the mixed solvent is stirred at 20-90 ℃ to enable the solute to be completely dissolved until the solute is completely dissolved, so that a mixed solution is obtained; (2) Titrating the mixed solution obtained in the step (1) by methanol, and stopping titrating when white powder appears; (3) Filtering the mixed solution obtained in the step (2) by using a filter head to obtain filtrate; (4) Sealing the filtrate obtained in the step (3) to obtain a growth device; (5) Placing the growth device obtained in the step (4) into a sealed container filled with methanol, and keeping the temperature at 40-80 ℃ for 3 days to obtain Cs (Ag 1-x Cu x ) 2 I 3 crystals; in the step (1), csI, agI and CuI are added into a mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide, wherein the addition amounts of CsI 1 mmol/mL, agI 2 (1-x) mmol/mL and CuI 2x mmol/mL are respectively 0< x less than or equal to 0.8.
  2. 2. The method according to claim 1, wherein the volume ratio of N, N-dimethylformamide to dimethyl sulfoxide in the step (1) is 1:1.
  3. 3. The method according to claim 1, wherein the filter head in step (3) has a filter diameter of 0.22. Mu.m.
  4. 4. The method of claim 1, wherein the step (4) is performed by pouring the filtrate into a beaker, sealing the beaker with a piece of tin foil and parafilm, and punching a plurality of small holes in the tin foil to allow the antisolvent to diffuse into the solution through the small holes.

Description

Preparation and application of lead-free halide Cs (Ag 1-xCux)2I3 Technical Field The invention relates to preparation and application of lead-free halide Cs (Ag 1-xCux)2I3, belonging to the field of photocatalytic organic matter degradation. Background With the rapid development of global industrialization, environmental pollution problems are increasingly prominent, and especially pollution seriously threatens human health. Therefore, advanced treatment techniques capable of effectively removing organic contaminants from water and air are particularly important. In recent years, research on degrading organic pollutants by means of green pollution-free solar energy has been paid great attention. Some metal oxides and sulfides are reported to have better photocatalytic properties, but the high recombination rate of electron-hole pairs limits their practical application. Lead halide (APbX3;A＝CH3NH3+,CH(NH2)2+,Cs+;X＝Cl-,Br-,I-) has been widely used in the fields of solar cells, photocatalytic synthesis, photocatalytic degradation, photocatalytic reduction of CO 2, photocatalytic hydrogen evolution, and the like due to its excellent optical characteristics. In these applications, lead halides exhibit excellent organic degradation characteristics. However, lead has high environmental and biotoxicity and poor stability, which limits the use of these materials. Therefore, the use of environmentally friendly metal ions to replace toxic lead elements is of great significance. Silver-based compounds have been used as substitutes for lead-free compounds due to their excellent optical properties and are applied in the field of ultraviolet light detectors. In the photocatalysis process, not only the stability of materials is ensured to ensure the photocatalysis efficiency, but also the forbidden band width is regulated to improve the utilization rate of sunlight. Researchers have found that the atomic orbitals of the B-site element in the doped compound directly affect its valence and conduction bands, and therefore metal ion doping is considered to be one way of adjusting the bandgap and optoelectronic properties. Copper has potential application value in doping as a transition metal with smaller ionic radius. Disclosure of Invention In order to solve the problems of the existing lead halides, the invention provides a preparation method of lead-free halide Cs (Ag 1-xCux)2I3, which comprises the following specific steps: (1) CsI, agI, cuI is dissolved in a mixed solvent of N, N-Dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), and the solution is stirred at 20-90 ℃ to completely dissolve the solute until the solute is completely dissolved, so as to obtain a mixed solution. (2) The mixed solution obtained in step (1) was titrated with methanol, and the titration was stopped when white powder appeared. (3) And (3) filtering the mixed solution obtained in the step (2) by using a filter head to obtain filtrate. (4) And (3) sealing the filtrate obtained in the step (3) to obtain the growth device. (5) And (3) placing the growth device obtained in the step (4) into a sealed container filled with methanol, and keeping the temperature at 40-80 ℃ for 3 days to obtain Cs (Ag 1-xCux)2I3 crystals. Preferably, in the step (1), csI, agI and CuI are added into the mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide in an amount of 1mmol/mL of CsI, 1-x mmol/mL of AgI 2 and 2x mmol/mL of CuI, wherein 0< x <1. Preferably, x= 0.2,0.4,0.6 or 0.8. Preferably, in the step (1), the volume ratio of DMF to DMSO is 1:10-10:1. Preferably, the filter head in step (3) has a filter diameter of 0.22. Mu.m. Preferably, the filtrate in the step (4) is sealed by pouring the filtrate into a beaker, sealing with tinfoil and parafilm, and punching a plurality of small holes on the tinfoil to allow the antisolvent to diffuse into the solution through the small holes. The invention also provides application of the lead-free halide Cs (Ag 1-xCux)2I3 in photocatalytic degradation of organic pollutants). The principle of the invention is as follows: Under light conditions, the electron transition of Cs (Ag 1-xCux)2I3 from the Valence Band (VB) to the Conduction Band (CB) yields e - and h + whereas-0.33 eV is located in Cs (band gap of Ag 1-xCux)2I3, which results in the catalyst surface dissolved oxygen capturing the electron in CB to form an O 2- group according to the standard redox potential to form O 2- according to the analysis above the possible photocatalytic process is as follows: Cs(Ag1-xCux)2I3+hv→e-+h+ (1) e-+O2→·O2- (2) ·O2-+MB→degradedproducts (3) The beneficial effects of the invention are that (1) The lead-free halide Cs (Ag 1-xCux)2I3 crystals can be applied to photocatalytic degradation of organic pollutants) prepared by the invention. (2) The Cu + part replaces Ag + in the invention, so that the band gap is narrowed, sunlight is better utilized, and meanwhile, the transmission of electrons and holes is facilitated. (3) Cs (Ag