A kind of preparation method and application of manganese oxide composite carbon nitride composite photocatalyst

Abstract

The invention provides a method for preparing manganese oxide composite carbon nitride nanotubes, using melamine as a precursor, and preparing carbon nitride nanotubes through a hydrothermal-calcination two-step method; Manganese oxide composite carbon nitride nanotube photocatalytic nanoreactor was prepared by deposition method. The composite photocatalytic nanoreactor has been proved to have good photoelectric performance by a series of characterization means, which is attributed to the modification of manganese oxide not only to improve the absorption of visible light by the nanoreactor, but also as the oxidation activity on the carbon nitride nanoreactor. The sites are enriched for photogenerated holes. The nanoreactor reacts with superoxide radicals (·O 2 ‑ ) and photogenerated holes as the main active oxidants to degrade target organic pollutants. The nanoreactor still maintained 80% of its photocatalytic oxidation performance after 5 cycles. The nano reactor has the advantages of high efficiency, stability and no secondary pollution. Exhibited excellent antibiotic degradation efficiency.

Description

technical field [0001] The invention relates to a preparation method and application of manganese oxide composite carbon nanotube composite photocatalyst. Background technique [0002] In recent years, the application of nanomicroreactors to the degradation of organic pollutants in wastewater has attracted extensive attention, because this process can make full use of clean and easily available visible light as the driving force of the reaction. Moreover, this method of photocatalytic degradation of antibiotics is efficient, stable and free of secondary pollution. [0003] Graphite carbon nitride (g-C 3 N 4 , CN) is a typical polymer semiconductor with excellent characteristics of visible light response, stable, non-toxic, non-polluting, and easy to prepare. However, due to the limited specific surface area and oxidation active sites, large photocatalytic electronic transition energy threshold, and the rapid recombination of photogenerated carriers, the photocatalytic eff...

AI Technical Summary

Problems solved by technology

However, due to the limited specific surface area and oxidation active sites, large photocatalytic electronic transition energy threshold, and the rapid recombination of photogenerated carriers, the photocatalytic efficiency of CN alone is very low, so it can participate in the photogeneration of effective reduction / oxidation reactions. Electronics (e - ) and holes (h + ) is limited in number, so the efficiency of catalytic oxidation to degrade organic pollutants is limited

[0004] In CN105817255A, manganese acetate and carbonitride precursor raw materials are jointly calcined to obtain manganese oxide / graphite phase carbon nitride composite photocatalytic material; in CN110876951AH, carbon nitride matrix, metal salt and sodium hydroxide solution are mixed, and the Metal oxide particles are supported on the carbon nitride substrate; CN108786874A passes the divalent manganese salt with g-C 3 N 4 The surface of the incompletely reacted -NH 2 complexation between adsorption to g-C 3 N 4 Then add potassium permanganate to generate manganese dioxide / carbon nitride composite photocatalytic material; although the composite material prepared by the above method can improve the catalytic activity of graphite phase nitrogen carbide, the manganese dioxide of the above method is in the graphite phase The dispersion of carbon nitride on the surface is poor, and the effect of improving the catalytic activity of antibiotics is very limited

However, the catalytic activity of antibiotics is not ideal, and there is still room for further improvement

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