Modulating interfacial electron transfer in hydrothermal carbon/ humboldtine to achieve superior heterogeneous Fenton reactivity and H2O2 utilization efficiency

Abstract

The strategic enhancement of interfacial electron transfer dynamics between carbon and iron, coupled with the improvement of H2O2 ' s effective decomposition, is imperative for achieving significant progress in the field of iron-carbon-based heterogeneous Fenton catalysis. This study prepared a novel Fenton catalyst, namely hydrothermal carbon/humboldtine (HTC/Hum), where Fe(III) was totally reduced to Fe(II) during catalyst preparation process due to the highly effective electron transfer between carbon and iron. Consequently, HTC/Hum exhibits exceptional Fenton catalytic performance, which would achieve 100 % degradation of Bisphenol A (BPA) within 5 min, outperforming conventional carbon-iron materials by increasing BPA degradation and H2O2 utilization efficiency by 230-400 and 18-24 times, respectively. Density functional theory (DFT) calculations also indicated that the energy barrier for HO center dot escaped from HTC/Hum is significantly lower than the conventional catalysts. Xray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), and electrochemical analysis all demonstrated that the electron transfer from carbon to iron also occurred continuously in the HTC/Hum system during the Fenton reaction, facilitated by electrons from defects and persistent free radicals in HTC, promoting the redox cycle of Fe(III)/Fe(II). This study presents a novel strategy enhancing electron transfer and H2O2 utilization, with promising applications in environmental remediation