Simple method for preparing Co-Nx/C efficient selective photocatalyst

Abstract

Depletion of energy resources and environmental pollution are two problems needing to be resolved immediately at present, and rich solar energy provides an efficient path for solving the two problems. Effective conversion of luminous energy and chemical energy cannot be performed without a photosensitive nano-material with excellent photocatalytic activity. A metal-organic complex serves as a precursor, and the Co-Nx / C efficient selective photocatalyst is prepared through a simple one-step heat polymerization method. The invention belongs to the field of carbon material science. The organic ligand is selected from dimethylglyoxime with low price and high coordination ability, a low-price transition metal salt (cobalt chloride) is selected in the metal center, and after high-temperature calcinations, the catalytic active site (Co-Nx) is successfully introduced into the catalyst. The Co-Nx / C catalyst is capable of selectively sensitizing oxygen so as to produce high-activity singlet oxygen. The Co-Nx / C active center is formed, the energy difference (Delta EST) between a singlet state and a triplet state is reduced, the intersystem crossing (ISC) process is promoted, production of the singlet oxygen is enhanced, and the selective photocatalytic oxidation ability is improved.

Description

technical field [0001] The invention uses a metal-organic complex as a precursor to prepare a Co-Nx / C high-efficiency and selective photocatalyst through a simple one-step thermal polymerization method, and belongs to the field of carbon material science. Diacetyl oxime, which is cheap and has strong coordination ability, is selected as the organic ligand, and the transition metal salt (cobalt chloride) is selected as the metal center. After high-temperature calcination, the catalytic active center (Co-Nx) is successfully introduced into the catalyst middle. The Co-Nx / C catalyst can selectively sensitize molecular oxygen to generate highly active singlet oxygen. The present invention forms the Co-Nx active center through the coordination of metal center cobalt and pyridine nitrogen, which is beneficial to reduce the energy difference between the singlet state and the triplet state (△E ST ), to promote the intersystem crossing (ISC) process, which is conducive to enhancing th...

AI Technical Summary

Problems solved by technology

However, the quantum yield of singlet oxygen is not high. Only with the help of efficient photosensitizers can molecular oxygen obtain energy and convert into singlet oxygen.

[0003] Over the past few decades, a series of photosensitizers have been used to generate 1 o 2 : heavy atom (bromine, iodine) doped organic dyes, porphyrin and its derivatives, noble metal nanoparticles, semiconductor quantum dots and fullerene derivatives, etc., but due to the low quantum yield and poor selectivity of such photosensitizers , high cost and high toxicity, which greatly limit their application

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