Flexible construction of RGO-encapsulated fine Pd/α-Fe2O3 composite with elevated Photo-Fenton reaction performance

Abstract

A novel Pd/α-Fe2O3@RGO composite is prepared by modifying the fine α-Fe2O3 with Pd nanoparticles (NPs) and encapsulated in reduced graphene oxide (RGO), which has excellent Fenton performance and its efficiency can be further promoted with visible-light assistance (up to 41.8%). The joint modification of Pd NPs and RGO was employed to address the restriction of α-Fe2O3 in Photo-Fenton (Ph-F) reaction. Meanwhile, the massive H2O2 supplement can be avoided by Pd NPs catalyzing HCOOH and O2 to in-situ generate H2O2. The α-Fe2O3 particle size (60-80 nm) and graphene ratio fraction (GRF, 20 wt%) were also optimized that the Pd/Fe2O3-1@0.20GRF exhibits the best Ph-F performance (100%) for AR73 degradation (150 mg/L, 50 mL) within 60 min. The diffuse reflection spectra (DRS) results indicate the catalyst has the strongest light utilization capacity, and the effective carrier transport and remarkable effect on inhibition of electron-hole recombination were identified by photoluminescence (PL), photocurrent and electrochemical impedance spectroscopy (EIS). Furthermore, the encapsulation of Pd/α-Fe2O3 in RGO was approved to enhance photoresponse capacity and maintain good stability during the consecutive Ph-F reaction. This work provides an insight for the development of Fe-based catalyst with high Ph-F efficiency and long-term steadiness.