Pyroelectric effect in CdS nanorods decorated with a molecular Co-catalyst for hydrogen evolution

Hexagonal cadmium sulfide (CdS) with a noncentro-symmetric structure exhibits piezoelectric and pyroelectric effect due to spontaneous polarization changes companied by temperature variation. However, its pyroelectric effect in pyroelectro-catalytic hydrogen evolution has not been well identified. Herein, we found that CdS nanorods decorated with an organic molecule 2-mercaptobenzimidazole (2MBI) can greatly enhance the pyroelectro-catalytic hydrogen evolution activity. The 2MBI acted as a molecular co-catalyst improves the pyroelectric property of CdS and enhances the separation of pyroelectro-induced charges. Under thermal cycling between 25 degrees C and 55 degrees C, CdS-2MBI shows apparently improved pyroelectro-catalytic H-2 evolution activity, which is about 5 folds of that for CdS alone. This work may initiate a new prospect for pyroelectric effect in photocatalysis, such as the photocatalytic hydrogen evolution under natural temperature fluctuations.