Nitrogen Vacancy‐Induced Deposition of Pd Nanoparticles onto g‐C3N4 with Greatly Improved Photocatalytic Activity in H2 Evolution

Abstract

C3N4 exhibits excellence in photocatalytic water splitting. However, some hindrances should be overcome before its wide application. Herein, nitrogen vacancies (NVs) are successfully introduced in C3N4. As‐fabricated NVs act as targets to induce the deposition of Pd nanoparticles (NPs). Photocatalytic activity in H2 evolution for C3N4 is improved from none to 10.12 μmol h−1 gcat−1 in the presence of NVs, and to 287.94 μmol h−1 gcat−1 with the modifications of both NVs and Pd NPs. The great improvement may be due to that: 1) the formation of NVs can drive up the Fermi level and optimize the band structure of C3N4; 2) the addition of the impure energy level of NV within the bandgap expands the utilization of the solar spectrum; 3) Pd NPs with the surface plasmonic resonance (SPR) effect are capable of absorbing more visible‐light photons; and 4) Pd acts as a reservoir of photogenerated charge carriers, suppressing its recombination. The mechanism of the enhancements is explored in detail and comprehensively discussed in this work.