Construction of S-scheme Co3O4/g-C3N4 heterojunctions with boosted photocatalytic H2 production performance

The key step of photocatalytic technology using light energy to split water for hydrogen production is to prepare high performance and environmentally friendly stable photocatalysts . In this study, Co 3 O 4 was loaded onto polymeric carbon nitride (PCN) to construct S-scheme heterojunctions by an impregnating method. The successful construction of S-scheme Co 3 O 4 /PCN heterojunctions was proved by the various characterizations, the constructed S-scheme Co 3 O 4 /PCN heterojunctions have favorable photoelectric effect and exhibit better H 2 evolution performance than the single Co 3 O 4 and PCN. Construction of S-scheme Co 3 O 4 /PCN heterojunctions can elevate active sites induced by N-deficient formation. Therein, 3% is the optimal molar ratio of Co/PCN, and the corresponding sample (3CoO/CN) exhibits the highest H 2 evolution efficiency (105.06 μmol· g − 1 · h − 1 ) via simulated solar light illumination for 4 h, which is about 41 folds higher than the single PCN (2.48 μmol· g − 1 · h − 1 ). In short, the conspicuously boosted water splitting efficiency is mainly due to the strong light responsiveness and rapidly separation and migration of photoexcited charge pairs. The cyclic experiment results show that the S-scheme Co 3 O 4 /PCN heterojunction photocatalysts have high stability. The apparent quantum efficiency (AQE) of H 2 generation on 3CoO/CN is 0.053% under 420 nm monochromatic light irradiation . This study strongly verifies that construction of S-scheme Co 3 O 4 /PCN heterojunctions is a feasible route to boost the photocatalytic activity of g-C 3 N 4 , providing an interesting reference for design highly efficient and environmentally friendly C 3 N 4 -based photocatalysts.