Novel P-n Li 2 SnO 3 /g-C 3 N 4 Heterojunction With Enhanced Visible Light Photocatalytic Efficiency Toward Rhodamine B Degradation.

The design of highly efficient and stable photocatalysts to utilize solar energy is a significant challenge in photocatalysis. In this work, a series of novel p-n heterojunction photocatalysts, Li2SnO3/g-C3N4, was successfully prepared via a facile calcining method, and exhibited superior photocatalytic activity toward the photodegradation of Rhodamine B solution under visible light irradiation as compared with pure Li2SnO3 and g-C3N4. The maximum kinetic rate constant of photocatalytic degradation of Rhodamine B within 60 min was 0.0302 min(-1), and the composites still retained excellent performance after four successive recycles. Chemical reactive species trapping experiments and electron paramagnetic resonance demonstrated that hydroxyl radicals (center dot OH) and superoxide ions (center dot O2-) were the dominant active species in the photocatalytic oxidation of Rhodamine B solution, while holes (h(+)) only played a minor role. We demonstrated that the enhancement of the photocatalytic activity could be assigned to the formation of a p-n junction photocatalytic system, which benefitted the efficient separation of photogenerated carriers. This study provides a visible light-responsive heterojunction photocatalyst with potential applications in environmental remediation.