Hydrothermally prepared unactivated bean sprouts biochar supported CdS with significantly enhanced photocatalytic hydrogen evolution activity

Unactivated bean sprout (Faba pullulat) biochar (BSB) supported cadmium sulfide composites (CdS/BSB) were prepared by hydrothermal combined with freeze-drying without adding any activation agent. The structure and morphology have been characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) in detail, respectively. CdS/BSB(5:4) with a mass ratio of CdS to BSB of 5:4 had the highest photocatalytic hydrogen production rate of 17.7 mmol.g−1.h−1, which is about 3.93 and 3.2 times that of synthesized CdS without biochar and the commercial activated carbon supported CdS, respectively. These results suggested that biochar derived from bean sprout could be a low-cost, renewable, environmentally friendly and metal-free cocatalyst for hydrogen generation.