Interfacial Nucleation Mechanism of Water-Soluble Ag–In–S Quantum Dots at Room Temperature and Their Visible Light Catalytic Performance

Abstract

A novel interfacial reaction nucleation mechanism for the preparation of water-soluble Ag−In−S quantum dots (AIS QDs) was proposed in which interfacial acid regulates the concentration of hydroxide ions outside the complex and sulfur sources attack cations at the interface of the complex, covalent bonds between cations and sulfur sources are formed at the interface of the complex, and the nucleation and growth of crystals is finished at room temperature. By bypassing the heating process normally necessary for crystal nucleation and growth, AIS QDs can be produced on a large scale under simple, mild conditions. At the same time, the characteristics of this mechanism enable AIS QDs to be directly synthesized in an organic pollutant solution. This study represents a significant advance in the mechanism of crystal synthesis and contributes to the photocatalytic decomposition of organic pollutants from theory to practice.

Water-Soluble Ag–Sn–S Nanocrystals Partially Coated with ZnS Shells for Photocatalytic Degradation of Organic Dyes

“…h + is directly involved in the photocatalytic oxidation reaction during MO degradation by ATS NCs, which also verified that the lower the pH value of the precursor solution, the higher the photocatalytic degradation efficiency of the prepared ATS NCs. According to our previous report, the solution with a low pH value has more free H + ions, which makes the holes on the photocatalyst surface more stable and maintains the reactivity at the photocatalyst interface, thus improving the photocatalytic efficiency. , At the same time, H + in solution consumes the OH – outside of the complex, and the OH – species are widely believed to prevent oxygen–reduction reactions (ORR). − …”

“…When the hydroxide outside of the complex is consumed, the energy barrier for converting the precursor to monomers decreases, when the energy barrier is reduced to 1/3 of the Gibbs free energy required to form the monomer, the sulfur source in the process of competing with hydroxide cation, sulfur source and cation precursor in the complex interface into nanocrystal monomers, and generate ATS nanocrystals. 16,17 Due to the addition of interfacial regulatory acids, the pH of the precursor solution is Using interfacial regulating acids to remove hydroxide ions outside the complex allows ligand and sulfur sources to react at the interface to form a Ag−Sn−S covalent bond, which is then nucleated and grown into crystal seeds. Figure S1 shows the UV−visible absorption spectra of Ag 2 SnS 3 nanocrystals prepared using different interfacial regulating acids.…”

“…According to our previous report, the solution with a low pH value has more free H + ions, which makes the holes on the photocatalyst surface more stable and maintains the reactivity at the photocatalyst interface, thus improving the photocatalytic efficiency. 16,17 At the same time, H + in solution consumes the OH − outside of the complex, and the OH − species are widely believed to prevent oxygen−reduction reactions (ORR). 60−62 Photocurrent and electrochemical impedance spectroscopy (EIS) tests also showed the same results.…”

Construction of Three‐Dimensional In‐Zn‐Cd‐S Composite Materials and Their Visible‐Light Catalytic Performance

“…Among them, metal sulfide system has attracted extensive attention due to its unique band position, crystal structure and catalytic function. [3][4][5][6][7][8][9][10][11] Binary sulfides with narrow band gaps (such as CdS, In 2 S 3 , SnS 2 , Cu 2 S) and ternary chalcogenides (such as ZnIn 2 S 4 , CdIn 2 S 4 , SnIn 4 S 8 ) are good candidate photocatalysts for visible light catalytic hydrogen production and degradation of organic dyes. [10] However, these sulfide photocatalysts still face the challenges faced by most photocatalysts, such as low photocatalytic efficiency caused by fast recombination of photogenerated electron-hole pair and photocorrosion caused by photogenerated hole oxidation of S metal bond.…”

“…In view of the efficient utilization of solar energy, many attempts have been made to develop different kinds of visible light active photocatalysts in recent years. Among them, metal sulfide system has attracted extensive attention due to its unique band position, crystal structure and catalytic function [3–11] . Binary sulfides with narrow band gaps (such as CdS, In 2 S 3 , SnS 2 , Cu 2 S) and ternary chalcogenides (such as ZnIn 2 S 4 , CdIn 2 S 4 , SnIn 4 S 8 ) are good candidate photocatalysts for visible light catalytic hydrogen production and degradation of organic dyes [10] .…”