Construction of S-scheme PbBiO2I/La(OH)3 Heterojunction with Synergistic Photocatalytic Nitrogen Fixation and Degradation Function

Abstract

Developing efficient photocatalysts for simultaneous nitrogen fixation and pollutant degradation remains a huge challenge for practical application of photocatalysis. This work fabricated a novel 1D/2D La(OH)₃/PbBiO₂I S-scheme heterojunction photocatalyst initially via hydrothermal synthesis. The composite displayed superior photocatalytic activity in both photocatalytic N₂ fixation with air and RhB photodegradation. Notably, the optimal La(OH)₃/PbBiO₂I composite (designated as ICL6) achieved maximal activity enhancement for both reactions among all photocatalysts. Morphology, structure, optical traits, and photoelectrochemical properties were comprehensively investigated using multiple characterization techniques. Analyses confirmed random dispersion of 1D La(OH)₃ nanorods on 2D PbBiO₂I nanoplates. Fermi level disparity revealed PbBiO₂I’s higher energy than La(OH)₃, inducing electron migration from PbBiO₂I to La(OH)₃ to establish an internal electric field (IEF). Driven by this IEF and band bending, La(OH)₃ conduction band (CB) electrons rapidly transferred to PbBiO₂I’s valence band (VB), thus boosting charge separation. Consequently, electrons in PbBiO₂I’s CB and holes in La(OH)₃’s VB retained potent redox capacities. The enhanced photocatalytic performance stems primarily from efficient carrier separation enabled by the S-scheme pathway and novel 1D/2D nanostructure. This study paves the way for designing novel photocatalysts with dual functions for N₂ fixation and dye degradation.