An in situ mediator-free route to fabricate Cu_2O/g-C3N_4 type-Ⅱ heterojunctions for enhanced visible-light photocatalytic H_2 generation

摘要

Graphical abstractDisplay OmittedHighlights•Cu2O particles were successfully in situ doped in the g-C3N4matrix.•Cu2O/g-C3N4hybrids exhibit favorable photocatalytic properties.•The broad absorption of Cu2O/g-C3N4hybrids can boost the hydrogen generation.•A profound view into photocatalytic mechanism of Cu2O/g-C3N4was discussed.AbstractCu2O nanoparticles doped g-C3N4are synthesized via an in situ method and investigated in detail by IR techniques, X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, ultraviolet visible diffuse reflection spectroscopy, and photoluminescence spectroscopy. The as-prepared Cu2O/g-C3N4hybrids demonstrate enhanced photocatalytic activity toward hydrogen generation compared to pure bulk g-C3N4, the effect of Cu2O content on the rate of visible light photocatalytic hydrogen evolution reveals the optimal hydrogen evolution rate can reach 33.2 μmol h−1 g−1, which is about 4 times higher that of pure g-C3N4. The enhanced photocatalytic activity can be attributed to the improved separation and transfer of photogenerated electron–hole pairs at the intimate interface between g-C3N4and Cu2O. A possible photocatalytic mechanism of the Cu2O/g-C3N4composite is also discussed. This mediator-free in situ chemical doping strategy developed in this work will contribute to the achievement of other multicomponent photocatalysts.