Boosting Visible-Light Hydrogen Evolution Through Synergistic Dual-Heteroatom Doping and 3D Hierarchical Porous g-C₃N₄ Nanocorals

Addressing global energy and environmental challenges requires innovative advancements in sustainable technologies. Photocatalytic hydrogen evolution (PHE) is a promising approach for clean energy production through the efficient conversion of solar energy into hydrogen. Despite ongoing challenges, improving the structural design and photo/electrochemical properties of graphitic carbon nitride (g-C₃N₄) remains essential for boosting the efficiency of PHE, contributing to solutions for the energy crisis and environmental pollution. Herein, we present a novel 3D hierarchical porous g-C₃N₄ nanocoral structure doped with sulfur and oxygen (3D SO-CN1), synthesized via a simple hydrothermal approach followed by calcination. The unique nanocoral architecture significantly increases the surface area, providing abundant active sites while promoting efficient light absorption and charge carrier separation compared with pristine g-C₃N₄. As a result, the 3D SO-CN1 catalyst loaded with 3 wt% Pt exhibits an impressive hydrogen evolution rate of 27.38 mmol⋅g⁻¹⋅h⁻¹ under visible-light irradiation, using 15 vol% triethanolamine (TEOA) as a sacrificial agent. Notably, the proposed 3D SO-CN1 catalyst exhibits 51-fold enhancement compared to pristine g-C₃N₄. Additionally, it exhibits a notable apparent quantum efficiency (AQE) of 5.26% at 420 nm, highlighting its superior photocatalytic performance. This study underscores the synergy of dual heteroatom doping and morphological engineering in optimizing g-C₃N₄ for next-generation sustainable hydrogen production.