Engineering of Two-Dimensional Heterostructures for Enhanced Photocatalytic Decontamination of Methyl Orange.

Two-dimensional (2D)/2D heterostructured catalysts have garnered significant attention in photocatalytic environmental remediation due to their relevance in optoelectronic, as well as solar energy conversion systems. However, fast photocarrier separation of 2D/2D heterojunctions, made from the stacking of different layered materials through strong chemical bonds rather than weak van der Waals interactions, remains an unmet challenge. To address this, herein, a generation of 2D/2D p-n heterojunction photocatalysts, composed of BiOCl and HMo Nb O nanosheets, was fabricated via chemical absorption and hydrolysis strategies. This close heterojunction interface enhanced the separation and migration of photoinduced electron-hole (e-h) pairs. As a result, the prepared ultrathin BiOCl/HMo Nb O heterostructure catalysts demonstrated superior photocatalytic degradation of methyl orange (MO) under UV-visible light, with the optimized photocatalysts (BiOCl/NbMo) achieving MO removal efficiencies 2.94 and 2.22 times greater than those of pristine BiOCl and NbMo materials, respectively. Further, hydroxyl radicals (·OH), positive holes (h), and superoxide anions (·O ) were also confirmed to play key roles in MO removal within the photocatalytic system. This work offers insights into the rational design and construction of high-performance 2D/2D heterojunction photocatalysts for environmental remediation.