Narrow bandgap 1D g-C3N4/3D-Bi2MoO6 self-assembled heterojunction structure with enhanced photocatalytic performance for removal of MB or Cr (VI)

The wide bandgap structures and rapid carrier recombination are major factors limiting the photocatalytic activity of semiconductors. In this work, one dimension (1D) g-C₃N₄ with narrowed bandgap (1DCN) and three dimension (3D) Bi₂MoO₆ with inter-crossed nanosheet structure were combined into a heterojunction by a simple self-assembly method, which greatly improved the degradation efficiency of pollutants (methylene blue (MB) and Cr(VI)). The results showed that the degradation efficiency of MB by 1DCN/Bi₂MoO₆ could reach 97% after 210 min, and the reduction rate of Cr(VI) could reach more than 75% within 50 min under an illumination source of a 500W lamp source. The trapping analyses were performed and exhibited that the key reactive species in the 1DCN/Bi₂MoO₆ photodegradation were ·O₂⁻ and OH radicals in the reaction. In addition, the combined structure of 1D/3D effectively reduces the electron transport distance and increases the electron transfer rate, thereby further improving the catalytic effect of the heterojunction. The excellent catalytic activities of 1DCN/Bi₂MoO₆ have broad application prospects and provide reference for the combination of other heterostructures.