(F, K)-Co-Doped Carbon Nitride for Enhanced Photocatalytic Hydrogen Production

Abstract

Visible-light-driven photocatalytic hydrogen production is one of the ideal green technologies for solar-to-chemical energy conversion. Carbon nitride (C3N4, CN) has been attracting extensive attention for its suitable band structure and stability, but the efficiency of photocatalytic hydrogen evolution is low due to insufficient visible-light absorption and rapid charge recombination. Herein, we develop a novel (F, K)-co-doped CN (FKCN) catalyst via a facile thermal polymerization approach using KOH-modified melamine and NH4F as the dopant precursors. The FKCN catalyst demonstrates broadened light absorption, significantly enhanced charge separation, and excellent cyclic stability. And the optimal F(0.15)K(6)CN catalyst achieves a hydrogen evolution rate of as high as 3101.5 μmol g−1 h−1 (12-fold that of pristine CN) under visible-light irradiation (λ ≥ 420 nm), which is among the best element-doped CN photocatalysts. This work highlights the effectiveness of a multi-element doping strategy in designing CN-based photocatalysts for efficient hydrogen evolution.