(Oxy)nitride heterojunction-strengthened separation of photogenerated carriers in g-C3N4 towards enhanced photocatalytic H2 evolution

The metal-free graphitic carbon nitride (g-C3N4) with a series of merits like low cost, favorable stability, and controllable two-dimensional graphite-like structure, has been extensively studied for photocatalytic H2 evolution. Composite engineering is regarded as one of effective strategies to adjust the kinetics of photogenerated carriers in g-C3N4 for elevating its photocatalytic performance. Herein, the composite system of g-C3N4 with oxynitride LaTiO2N was elaborately constructed for improving photocatalytic H2-evolution performance. With systematical characterizations, the partial cover of g-C3N4 nanosheets on LaTiO2N (LaTiO2N@g-C3N4) was verified and promoted the sufficient contact between g-C3N4 and LaTiO2N, accompanied by the formation of the (oxy)nitride heterojunction. Benefited by the well-matched band structures for g-C3N4 and LaTiO2N, the (oxy) nitride heterojunction strengthened the separation of photogenerated carriers and therefore enhanced the photocatalytic performance of g-C3N4. This work gives more insight in composite engineering on g-C3N4, and also provides feasible guidelines for designing g-C3N4-based photocatalysts towards improving photocatalytic performance.

Automated summary

This study constructs a composite system of g-C3N4 with LaTiO2N to improve the photocatalytic H2 evolution performance of g-C3N4. By partial coverage of g-C3N4 nanosheets on LaTiO2N surface and the formation of (oxy)nitride heterojunction, the separation of photocarriers is enhanced, leading to enhanced photocatalytic performance.