The construction of a heterostructured RGO/g-C 3 N 4 /LaCO 3 OH composite with enhanced visible light photocatalytic activity for MO degradation.

The construction of a heterojunction and the introduction of a cocatalyst can both promote the transfer of photogenerated electrons, which are effective strategies to enhance photocatalytic efficiency. In this paper, a ternary RGO/g-C 3 N 4 /LaCO 3 OH composite was synthesized by constructing a g-C 3 N 4 /LaCO 3 OH heterojunction and introducing a non-noble metal cocatalyst RGO through hydrothermal reactions. TEM, XRD, XPS, UV-vis diffuse reflectance spectroscopy, photo-electrochemistry and PL tests were carried out to characterize the structures, morphologies and carrier separation efficiencies of products. Benefiting from the boosted visible light absorption capability, reduced charge transfer resistance and facilitated photogenerated carrier separation, the visible light photocatalytic activity of the ternary RGO/g-C 3 N 4 /LaCO 3 OH composite was effectively improved, resulting in a much increased MO (methyl orange) degradation rate of 0.0326 min -1 compared with LaCO 3 OH (0.0003 min -1 ) and g-C 3 N 4 (0.0083 min -1 ). Moreover, by combining the results of the active species trapping experiment with the bandgap structure of each component, the mechanism of the MO photodegradation process was proposed.