No abstract

The exploitation of recycled carbonaceous catalysts from renewable biomass resources such as chitin is a crucial issue for the development of the sustainable society. In this article, the chitin‐based N and O doped carbon microspheres (ChC) were fabricated by a simple dissolution, sol–gel transformation, and the carbonization methods. Subsequently, the novel magnetic Ag‐Fe3O4@chitin‐based carbon microspheres catalyst (MChC) was successfully constructed through the in situ redox reaction. The as‐prepared MChC possessed rich micropores with high‐surface area, and a narrow size distribution (50–120 μm). The Ag‐Fe3O4 nanoparticles were immobilized through the interaction with C, N, and O atoms in the pores of MChC. The reduction of 4‐nitrophenol was applied to evaluate the catalytic activity of MChC. 4‐Nitrophenol (4‐NP) could be fully reduced to 4‐aminophenol (4‐AP) in 5 min with the catalyst MChC‐45. Moreover, MChC could be collected in solution with an external magnet in 8 s and remained relatively high‐catalytic activity after 10 cycle times. This work provided novel ideas for the fabrication of doped carbon material from biomass and promoted its utilization in nanocatalytic applications.

Sulfites (HSO3-) are used as preservatives and additives in many foods and medicines. However, high sulfites can cause asthma attacks and even breathing difficulties. Sulfites can also be enriched in...