Engineering Schottky barrier and enhancing charge transfer kinetics via red phosphorus nanoparticles on g-C3N4/Ti3C2 for superior photocatalytic H2 production and CO2 reduction

2D nanomaterials emerge as promising photocatalysts, offering effective solutions for environmental remediation and addressing the global energy crisis. In this study, we engineered a functional heterojunction that integrates 2D g-C₃N₄, Ti₃C₂ (MXene) nanosheets, and RP nanoparticles, optimized through a simple and economical strategy to boost photocatalytic performance. The g-C₃N₄/RP/Ti₃C₂ photocatalyst showcases an optimal 2.66 eV band gap and well-defined pore width, notably improving visible light absorption. Red phosphorus integration, in controlled amounts, significantly enhances the physicochemical and photocatalytic characteristics of Ti₃C₂ and g-C₃N₄. The interaction between the heterostructures and nitrogen vacancies efficiently enhances charge transfer kinetics and control Schottky barrier height. The novel g-C₃N₄/RP/Ti₃C₂ heterostructure enhances the production of superoxide (•O₂^-) and hydroxyl (•OH) radicals, thereby boosting redox reaction efficiency. This multifunctional photocatalyst reveals significant effectiveness, achieving 99.2 % degradation of RhB within 90 min, 99.7 % degradation of TC in 60 min, a CO evolution rate of 150.9 μmol g⁻¹ h⁻¹, and a H₂ evolution rate of 19400 μmol g⁻¹ h⁻¹. Additionally, computational findings highlight the presence of structural defects, improved charge density, and a suitable band gap, establishing the photocatalyst as a viable solution for economical organic fuel generation and environmental remediation. This research introduces a novel method for the engineering of high-performance nanostructures that enhance photocatalytic activity.