CdS/g‐C3N4 Hybrids with Improved Photostability and Visible Light Photocatalytic Activity

Novel composite photocatalysts consisting of CdS and graphitic carbon nitride (CdS/g‐C3N4) with different ratios of CdS were prepared. The CdS/g‐C3N4 composite photocatalysts were characterized in detail and their photocatalytic activity was evaluated by using rhodamine B and colorless metronidazole as probes. Compared with pure g‐C3N4, the CdS/g‐C3N4 composite exhibits significantly enhanced photocatalytic activity under visible‐light irradiation. More importantly, g‐C3N4 substantially reinforces the photostability of CdS nanowires even in a nonsacrificial system. The synergistic effect between CdS and g‐C3N4 is found to be primarily responsible for enhancement of the separation of photogenerated electrons and holes, which helps improve the photocatalytic performance. A probable photodegradation process of metronidazole was proposed based on an analysis of the degradation products. This study provides new insight into the preparation of highly efficient and stable sulfide‐based composite photocatalysts and facilitates their application in a number of environmentally sensitive areas.