Hexagonal carbon nitride microtube doped with tungsten and nitrogen vacancies: Photocatalytic hydrogen evolution and efficient Fenton-like photocatalytic degradation of p-nitrophenol

Abstract

It has been found that the element doping and vacancy defects of the carbon nitride framework enhance its photocatalytic performance. In this article, we newly designed hexagonal carbon nitride microtube (W-TCN) with tungsten-doped and nitrogen vacancies in a layered stack structure through hydrothermal and in situ calcination methods. It is used to activate the high-efficiency Fenton-like photocatalytic degradation of peroxymonosulfate (PMS) and further studied the photocatalytic hydrogen evolution performance. Combining the Fenton-like process with photocatalysis driven by simulated sunlight, a cooperative catalytic system is realized to quickly remove p-nitrophenol (PNP) in water pollution. The prepared tubular W-TCN catalyst has excellent sunlight utilization efficiency, large surface area, abundant nitrogen vacancies, and narrow band gap due to the introduction of tungsten. These factors are conducive to the enhanced catalytic activity of W-TCN catalyst. Cyclic experiments and parallel experiments proved that the catalyst has good long-term stability. In particular, the degradation rate of PNP reached 98.6% under 90 min of irradiation in the optimal reaction system (W-TCN/PMS). Moreover, the hydrogen evolution performance of W-TCN catalyst is further studied, and it is found that in the presence of sacrificial agent, W-TCN also had a certain amount of hydrogen evolution, which is 91.46 μmol. The research ideas of this article proves that by adjusting the photocatalytic properties of carbon nitride materials, it has broad prospects in repairing environmental pollution under the synergistic effect of Fenton-like and photocatalysis. At the same time, further material optimization also has certain potential in solving the energy crisis.