Nanoscale zero-valent iron/cobalt@mesoporous hydrated silica core–shell particles as a highly active heterogeneous Fenton catalyst for the degradation of tetrabromobisphenol A

Abstract

Degradation of TBBPA by NZVI/NZVC@mHS CSP/H 2 O 2 heterogeneous Fenton system. • Synthesis of NZVI/NZVC@mHS CSP materials by one-pot method. • The core–shell structure of the material reduced aggregation and increased the specific surface area. • The mesoporous network structure effectively prevented the leaching of Co (II). • NZVI/NZVC@mHS CSP efficiently degraded TBBPA as Fenton-like catalyst. While the bimetal heterogeneous Fenton system degraded organic pollutants, the leaching of heavy metals caused secondary pollution. To resolve this problem, nanoscale zero-valent iron/cobalt@mesoporous hydrated silica core–shell particles (NZVI/NZVC@mHS CSP) were synthesized as a novel Fenton-like catalyst for the rapid degradation of Tetrabromobisphenol A (TBBPA). The performance of NZVI/NZVC@mHS CSP in the degradation of TBBPA and the mechanism of their action were investigated through scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. NZVI/NZVC@mHS CSP exhibited a regular spherical shape with a surface area (115.44 m 2 ·g −1 ) that was 5 times more than that of the ordinary NZVI/NZVC (23.59 m 2 ·g −1 ). The core of NZVI/NZVC was covered with a hydrated silica shell that formed a mesoporous network that effectively prevented the leaching of cobalt ions from the core. The best catalytic performance of NZVI/NZVC@mHS CSP was obtained by optimizing the iron-to-cobalt ratio, H 2 O 2 concentration, and the dosage of the catalyst. The optimized NZVI/NZVC@mHS CSP exhibited the greatest mineralization activity (97.13%) for TBBPA removal than those in NZVI/NZVC bimetal (84.49%) and pure NZVI/NZVC@mHS CSP (59.37%). Thus, our results demonstrated that NZVI/NZVC@mHS CSP exhibited excellent reactivity in potential application as a highly active heterogeneous Fenton catalyst for degradation of TBBPA in soil and groundwater.