Restacked melon as highly-efficient photocatalyst

Abstract

Abstract The graphitic carbon nitride photocatalyst with a layered melon structure (Melon) has attracted widespread interest. However, this photocatalyst still bears marginal optical absorption in the visible-light region, a high recombination rate of photoexcited charge carriers, and low photocatalytic activity. Here, a pressure-induced nanocrystalline carbon nitride photocatalyst with a distinct and restacked crystal structure of melon (Re-Melon) with highly efficient photocatalytic activity in the long-wavelength region are synthesized. X-ray diffraction, high-resolution transmission electron microscopy, and electron paramagnetic resonance spectroscopy results revealed the crystal structure of nanocrystalline Re-Melon with nitrogen deficiency. Ultraviolet–visible diffuse reflectance spectra, a transient photocurrent response, and valence-band X-ray photoelectron spectroscopy spectra uncovered enhanced light absorption, efficient charge migration, and well-matched energy level. All these properties contribute to excellent photocatalytic hydrogen production performance in visible-light and long-wavelength regions.