Construction of novel S-scheme LaFeO3/g-C3N4 composite with efficient photocatalytic capacity for dye degradation and Cr(VI) reduction

The novel LaFeO3/g-C3N4 composite system with S-scheme heterojunction was designed and prepared through the reasonable combination of admirable oxidation of LaFeO3 and robust reduction of g-C3N4, then treating the refractory organics and toxic heavy ions in water. The significant enhancement on the photocatalytic property not only derived from the sufficient active sites, but also originated from the extended life-span of charge carriers. Meanwhile, the three-dimensional structure and combined redox advantages of bicomponents helped the separation and transfer of electron-hole pairs, thus improving the photocatalytic performance. Upon these superior characters, the apparent rate constant of RB-19 degradation by LaFeO3/g-C3N4 composite was 2.3 times than that of LaFeO3 and 24.8 times than that of g-C3N4. While that for Cr(VI) reduction was calculated as 0.0172, which was 4.8 times than that of LaFeO3 and 10.3 times than that of g-C3N4. Satisfyingly, in the simulation tests with adding different inorganic metal ions or surfactants into the water environments, this nice system of LaFeO3/g-C3N4 exhibited the excellent practical stability, a proof that its application prospect was promising. Moreover, our study provides the efficient avenue to design and explore the novel heterojunction photocatalyst.