Porous dual Z-scheme InOOH/RCN/CoWO4 heterojunction with enhanced photothermal-photocatalytic properties towards norfloxacin degradation

Abstract

The effective separation of photogenerated carriers is still a key problem to be overcome in the preparation of efficient green photocatalysts. In this study, the direct dual Z-scheme heterojunction structure is constructed by combining InOOH with strong redox capacity and the CoWO4 with high electron mobility on the surface of reticular g-C3N4 (RCN). The comprehensive characterizations verify the three-phase coexistence of InOOH, CoWO4 and RCN. The systematic studies demonstrate that there are close heterojunction interfaces and well-matched band structures among them, which is conducive to improving the separation efficiency of photogenerated electron hole pairs. The photocatalytic result shows that the photocatalytic performance of the InOOH/RCN/CoWO4 composite is significantly superior to that of RCN, InOOH and CoWO4, and the degradation efficiency can reach 94 %, which could be mainly attributed to the construction of direct dual Z-scheme heterojunction. Furthermore, intermediates in the degradation process of InOOH/RCN/CoWO4 composite photocatalyst were detected by LC-MS, which confirmed the degradation products are green environmental protection. The possible degradation pathways and photocatalytic mechanism of InOOH/RCN/CoWO4 heterojunction were particularly discussed as well. These results provide a facile pathway for the preparation of high efficiency photocatalysts and the treatment of environmental pollution.