Development of ZFO family nanophotocatalysts: Clean hydrogen production by a new high performance photoreactor

Abstract

In this study, ZnFe₂O₄ (ZFO), Pd_0.2Zn_0.8Fe₂O₄ (PZFO), Ba_0.1Ca_0.1Mg_0.1Sr_0.1Zn_0.6Fe₂O₄ (BCMSZFO), Ca_0.2Co_0.2Cu_0.2Zn_0.4Fe₂O₄ (CCCZFO), Mg_0.2Mn_0.2Zn_0.6Fe₂O₄ (MMZFO), and Co_0.1Cu_0.1Mg_0.1Mn_0.1Ni_0.1Zn_0.5Fe₂O₄ (CCMMNZFO) nanospinels were synthesized via a hydrothermal method assisted by succinic acid. This material was evaluated for hydrogen production through photocatalytic water splitting under separate irradiation wavelengths of visible LED light. The chemical, physical, and photophysical properties of the ZFO family nanophotocatalysts were characterized using FT-IR, XRD, FESEM-EDX-MAP, UV–Vis DRS, and VSM. All synthesized nanospinels exhibited a pure spinel phase with no evidence of secondary crystalline phase. The direct band gap energies of ZFO, PZFO, BCMSZFO, CCCZFO, MMZFO, and CCMMNZFO were determined as 1.75, 1.51, 1.73, 1.50, 1.48, and 1.25 eV, respectively. Photocatalytic water splitting experiments were conducted under N₂ injection using a setup with operational parameters of 5 min irradiation time and 1 g of nanophotocatalyst mass. The hydrogen production rates of the nanophotocatalysts under identical conditions revealed significant differences, forming the basis for further investigations in this study.