Fabrication of interconnected flower-shaped macroporous P-doped g-C₃N₄ for enhancing visible-light-driven production of H₂ and H₂O₂

Developing visible light-responsive photocatalysts for converting solar energy into hydrogen (H₂) and hydrogen peroxide (H₂O₂) is an efficient strategy. Graphitic carbon nitride (g-C₃N₄) holds promise as a photocatalyst for solar-to-chemical energy conversion applications; however, its photocatalytic performance is hindered by sluggish charge separation and a limited specific surface area. Herein, we report 3D hierarchal P-doped interconnected flower-like macroporous g-C₃N₄, as a metal-free bifunctional photocatalyst capable of achieving high-efficiency photocatalytic production of both H₂ and H₂O₂ under visible-light irradiation. As a result of these advantages, optimized 10 % wt. 3DPCN10 has nearly 4.3 and 7.2 folds as much H₂ evolution (4513.6 μmol g⁻¹ h⁻¹) and H₂O₂ production (1321.3 μmol g⁻¹ h⁻¹), respectively compared to the unmodified g-C₃N₄. The outstanding photoactivity and stability of this bifunctional photocatalyst can be attributed to the efficient separation of photoinduced charge carriers, enhanced specific surface area, and interconnected p-doped porous framework which accelerate the chemical reaction on the surface of the photocatalyst. The findings presented in this study introduce an innovative approach to modify micro-nanostructured P-doped g–C₃N₄–based photocatalysts, enhancing their ability to capture and convert solar energy effectively.