α-Fe2O3/g-C3N4 nanocomposite with type II heterojunction for methylene blue photodegradation

Abstract

Recently, the widespread use of industrial dyes, such as methylene blue, is raising concerns about organic pollutants. These compounds can persist in the environment, contaminating water sources and harming aquatic ecosystems. The aim of the current study is to develop a nano-composite by mechanically grinding graphitic carbon nitride g-C3N4 and hematite α-Fe2O3, which cloud potentially be used for degradation of Methylene bleu organic pollutant. The obtained heterojunction nanocomposite, named 1 % α-Fe2O3/g-C3N4 (Fe/gCN), was characterized using XRD, ATR-FTIR, and SEM-EDS analysis. The industrial methylene blue (MB) dye was used to assess the visible light photodegradation efficiency of the Fe/gCN nanocomposite. The findings revealed a notable improvement in the photocatalytic degradation performance of the Fe/gCN nanocomposite. Furthermore, the band gap of Fe/gCN nanocomposite was narrowed from 2,78 to 2,54 eV Comparing to gCN alone. Compared with pure α-Fe2O3 and gCN, the Fe/gCN nanoparticles showed enhanced visible-light-induced photocatalytic performance which degrade efficiently 99,64 % of MB dye. The optimal conditions were determined as: pH =10,3, photocatalyst mass of 0,6 g/l and contact time t = 120 min for the Fe/gCN composite. •OH and •O2− radicals were identified as the dominant active species responsible for MB degradation and played the most crucial roles, while h+ and e− radicals were less contributing in MB photocatalytic elimination. Kinetic studies indicated that the MB photocatalytic decomposition of by Fe/gCN followed a pseudo second-order (PSO) model. These findings underscore the great potential of Fe/gCN nanocomposite for the visible light-induced MB dye photodecomposition.

Keywords

• α-Fe2O3/g-C3N4
• Heterojunction
• Methylene blue
• Radical scavenger
• Photo-fenton performance