One-pot synthesis of metakaolin/g-C3N4 composite for improved visible-light photocatalytic H2 evolution

The conversion of solar energy to chemical energy via photocatalysis is a potential pathway for future energy supplying, and the development of graphitic carbon nitride (g-C3N4) for visible-light photocatalytic hydrogen evolution reaction (HER) has attracted increasing attention. In this work, raw kaolinite was used to enhance the photocatalytic performance of g-C3N4 by constructing the metakaolin/g-C3N4 composites. A facile one-pot method, heat-treating their mixed precursors, was employed. The as-prepared MK/CN-70.4% exhibits a favorable hydrogen evolution rate of 288 μmol g−1 h−1, which is 1.5 times that of bulk g-C3N4. The improved HER benefits from both the electronegativity of metakaolin and the nanosizing of g-C3N4. The proposed strategy has the potential to inspire the utilization of other clay minerals to improve the photocatalytic activity of g-C3N4.