In situ construction of Z-scheme FeS 2 /Fe 2 O 3 photocatalyst via structural transformation of pyrite for photocatalytic degradation of carbamazepine and the synergistic reduction of Cr(VI)

• Published in: Journal of environmental sciences (China) 2021-03, Vol.101, p.351
• Main Authors: Guo, Qian, Tang, Guangbei, Zhu, Wenjie, Luo, Yongming, Gao, Xiaoya
• Format: Article
• Language: English
• Subjects: Carbamazepine; Catalysis; Chromium; Iron; Sulfides
• ISSN: 1001-0742

Pyrite is the most abundant sulfide semiconductor mineral with excellent optical properties. However, few reports have investigated its photocatalytic activity because of the low photogenerated carrier separation efficiency. In this work, a Z-scheme FeS /Fe O composite photocatalyst was fabricated in situ via structural transformation of pyrite through heat treatment. A remarkably enhanced photocatalytic performance was observed over the FeS /Fe O composite photocatalyst. Compared with the pristine pyrite, the degradation efficiency of carbamazepine (CBZ) reached 65% at the added hexavalent chromium (Cr(Ⅵ)) concentration of 20 mg/L and the Cr(Ⅵ) was nearly completely reduced in the mixed system using FeS /Fe O within 30 min under simulated solar light irradiation. The enhanced photocatalytic activity can be attributed to the efficient separation and transfer of photogenerated carriers in the FeS /Fe O composite photocatalyst. This facilitated the generation of •OH, hole (h ) and •O species, which participated in the photocatalytic reaction with CBZ. Based on the measurement of the active species and electric properties, a Z-scheme electron transfer pathway was proposed for the FeS /Fe O composite photocatalyst. This work broadens the application potential of pyrite in environmental remediation.