An effective Fenton reaction by using waste ferric iron and red phosphorus

Traditional Fenton reaction (Fe2+/H2O2) is limited by the instability and the sluggish regeneration of ferrous iron (Fe2+). Compared with Fe2+, ferric iron (Fe3+) is cheaper, easier to obtain and more stable. However, Fe3+- induced Fenton reaction activity is low. Here, a high-efficiency Fe3+-induced Fenton system is achieved by introduction of red phosphorus (P). The red P can donate electrons to Fe3+ for Fe2+ regeneration. As a result, the red P/H2O2/Fe3+ system exhibits three obvious advantages: i) The degradation rate of pollutant is 25.6 times and 18.3 times that of the Fe3+/H2O2 and red P/H2O2 systems. ii) The decomposition rate of H2O2 reaches an amazing value of 92.4%, which is much higher than that of the traditional Fenton system (51.6%). iii) Pollutants could be degraded efficiently with a wide initial pH range of 2.0-8.0, indicating that the red P/H2O2/Fe3+ system gets rid of pH constraints. Importantly, this study realizes the transformation of waste Fe3+ into treasure and resource reuse and further reduces the cost of Fenton reaction. Therefore, this study opens up a new strategy for utilization of widely-spread Fe3+ for environmental remediation and also provides a new application of red P.

Automated summary

A high-efficiency Fe3+-induced Fenton system was achieved by introducing red phosphorus (P). The system exhibited high degradation rate of pollutants and decomposition rate of H2O2, as well as efficient degradation of pollutants within a wide pH range. Additionally, the study realized the transformation of waste Fe3+ into a valuable resource, reducing the cost of Fenton reaction.