Study on the catalytic performance of Ag@AgBr/MgAl-LDH under photoelectric synergy

In this paper, the Ag@AgBr/MgAl-LDH complex was prepared by hydrothermal, precipitation and photoreduction methods, and the target product, methylene blue (MB) solution, was catalytically degraded under the condition of photoelectric synergy, and the catalytic activity of the samples was studied by the degradation rate. By combining with Ag@AgBr, Ag@AgBr/MgAl-LDH composite photocatalytic materials can be prepared. Ag@AgBr has the surface plasmon resonance (SPR) effect, and a certain voltage is applied to it by an electrochemical workstation, which can promote the efficient separation of photogenerated electrons from holes and greatly reduce the recombination of the two, and greatly improve the activity of catalytic degradation. This study provides an effective solution to the environmental problems caused by pollution such as industrial wastewater and organic dyes, and has important research value and application prospects. During the experiment, the photocatalytic performance of the sample was studied by the difference in the degradation rate of the sample to the methylene blue solution. Through a series of chemical characterization and photoelectric activity tests such as XRD and SEM of the prepared materials, the material composition, microscopic morphology and particle size and other parameters of the samples were determined. Parameters such as the electrochemical properties of materials are characterized by the use of potentiostats; The optimal modification amount of the catalyst was determined by exploring the degradation rate of the composite under different Ag@AgBr modification amounts of the sample. The recovery performance of the catalyst was characterized by multiple test cycle experiments on the samples. The reaction mechanism of the catalyst was determined by quenching experiments; The reaction mechanism of the active substance was determined by quenching the experiment. Through experiments, it is proved that when the Ag@AgBr modification amount is 12.5%, the photoelectric synergistic degradation rate of Ag@AgBr/MgAl-LDH is the highest, and the degradation rate can reach 90.97%. Through XRD, SEM, ultraviolet-visible diffuse reflection and Fourier transform infrared (FT-IR) characterization of the material, it was proved that the Ag@AgBr was successfully modified to MgAl-LDH, and the material also had good hydrophilic properties. A series of electrochemical performance tests were carried out on Ag@AgBr/MgAl-LDH by electrochemical workstation to characterize the electrochemical properties of the materials, and the results showed that the composite electrode materials had low barrier widths and impedances, high catalytic degradation ability, and more catalytic reaction active sites. After 5 cycle experiments, the material still has a high degradation rate, so it can be found that the composite material has very good stability, less catalyst loss and no significant degradation rate. The experimental results show that the active species in the process of photoelectric synergistic degradation of Ag@AgBr/MgAl-LDH are quenched by using different quenchers, and the experimental results show that the active species in the process are h+ and ${\cdot {\mathrm{O}}_2^- }$. Finally, combined with a series of characterization and test results in this experiment, the electron transfer mechanism of the Ag@AgBr/MgAl-LDH complex during the degradation process was further explored.