Photocatalytic hydrogen evolution from biomass (glucose solution) on Au/CdS nanorods with Au3+ self-reduction.

Glucose, as one of the most familiar biomass, can be utilized to produce hydrogen and fine chemicals. This work reports the renewable hydrogen production from glucose over Au/CdS-nanorods (Au/CdS-NRs) photocatalyst. For Au/CdS-NRs catalyst, it shows a superior H 2 evolution rate of 90.0 ​μmol ​g−1 ​h−1 under visible light irradiation. Moreover, the H 2 generation from the glucose solution on Au/CdS-NRs prepared by twice solvothermal method is much higher than Au colloid and photoreduction methods. Prepared with twice solvothermal method, Au nanoparticles are obtained from Au3+ ions on the CdS surface, as Au3+ can be reduced by photogenerated electrons. The separated hole can oxidize glucose to produce protons, and protons can be reduced by photogenerated electrons into H 2. Meanwhile, the Au/CdS-NRs can also be used to produce H 2 from other biomasses, for instance sucrose, soluble starch, celluflor, pectin and waste paper scraps. The probable mechanism is proposed and discussed in the photocatalytic process from glucose reforming. This work indicates that the process of self-reducing Au3+ to Au can drastically increase the photocatalytic efficiency of H 2 evolution from biomass, by promoting the separation and transportation of photogenerated charge carriers. Image 1 • Au/CdS nanorods was prepared by twice solvothermal method. • Au3+ can be reduced by photogenerated electrons in glucose solution. • Self-reduction of Au3+ can significantly improve the charge separation. • A photocatalytic mechanism was proposed and confirmed by several techniques. [ABSTRACT FROM AUTHOR]